[MaxGhenis]

Fixes #2307
Reproducer: policyengine_uk/tests/test_supplied_inputs.py::test_a_value_cached_over_an_input_is_not_supplied
axiom: n/a: simulation infrastructure, no policy rule change

Stacked on #2265. #2265 adds stored_supplied_value, and this PR builds on it rather than adding a second copy. This branch contains #2265's head, e804e8bc, and targets main, so CI runs on it. Land #2265 first: this PR's diff then shows only its own three files.

This branch merges main at 47a2817 (merge commit 3bce60e). main had added model values (set_model_value), copied populations and 38 more variables in SUPPLIED_INPUT_VARIABLES, and requires policyengine-core 3.33.0 or later (uv.lock pins 3.34.1).

0e44f0988 merges e804e8bc into 71fb10ca, with two conflicts. In simulation.py both sides added the subsample_simulation import, and the merge keeps one copy. In utils/supplied_inputs.py the module docstring keeps this PR's paragraph on tiers, which covers every helper, and #2265's sentence on model values in supplied_input_arrays. The merge also keeps this PR's _supplied_without_reading and #2265's is_model_value.

What was wrong

supplied_input and supplied_input_periods treated a value cached over a supplied input as supplied. #2307 reproduces it: after set_input of 100 and put_in_cache of 999 for the same period, supplied_input returned [999.] and supplied_input_periods returned [2025], while core's Holder._stores_user_input returned False. The same script on main at 47a2817 with policyengine-core 3.34.1 still prints [999.] and [2025], and core's Simulation._get_recorded_input_array returns None.

Why

Both helpers checked only two things: that core recorded the input (Simulation._user_input_keys), and that Holder._get_array_from_storage returned something. That method reads memory first, then disk, and does not ask whether the value it finds is the input. The record outlives a value cached over the input. put_in_cache stores over the input and takes that tier off the holder's record of where the input is (Holder._user_input_storage), but the _user_input_keys entry stays. So there were two wrong answers:

1. A value cached over the input in the same tier came back as supplied.
2. For an input stored on disk, with a value cached over it in memory, the helpers read memory and returned the cached value.

What changes

• supplied_input reads through stored_supplied_value (from Give UK simulations a working subsample #2265). That reads a supplied value only from a tier in which core's Holder._stores_user_input(period, branch_name, tier) finds the input: a tier that the holder records the input in and that holds a value the engine did not calculate. Memory comes before disk.
• supplied_input_periods uses the same rule. It finds the tier without reading the value, which may be on disk. It reads the value only when the model stored one for the period (set_model_value), to tell the model's value from a supplied one, as supplied_input does. stored_supplied_value and the periods helper share a private _supplied_value_storage. What stored_supplied_value returns stays the same.
• Unchanged:
  • Branch order. supplied_input still looks at this branch first, then each branch it was made from, then the default branch. If a branch's input has gone, it reads the next one, as core's _get_recorded_input_array does.
  • Model values. Neither helper returns a value the model stored with set_model_value while it stays the stored value.
  • Neutralised variables. A neutralised variable whose input survives reads as its default.
  • SUPPLIED_INPUT_VARIABLES and its check.
• Not changed: drop_missing_supplied_inputs. It forgets a record whose value has gone from both tiers, the population-rebuild case (policyengine-core#605). It keeps a record whose input a cached value has replaced. That does no harm now: the helpers ignore such a record, and so does core's input export (_stores_user_input).

Does this change results?

Not in normal calculation. The defect shows only when code stores a value with Holder.put_in_cache and its default derived=False, or with Holder._set.

• In policyengine-core 3.34.1, Simulation calls put_in_cache once, for each value it calculates, with derived=True.
• put_in_cache with derived=True stores nothing when the value get_array would read for that period is an input.
• Core's other writers store inputs: set_input and its period helpers, and the input replay in _invalidate_all_caches.
• The simulation dumper restores a dump into a new simulation, one value for each variable and period, so it stores nothing over an input either.
• policyengine-uk code outside its tests calls neither put_in_cache nor Holder._set.
• A code search of the PolicyEngine organisation found direct put_in_cache calls only in US code: one crfb-tob-impacts worker and two policyengine-us tests.

test_calculating_leaves_every_supplied_value_supplied executes this claim. It supplies all 45 variables in SUPPLIED_INPUT_VARIABLES for two years, each with a value of its own type for its own period, on the default branch, and one more input on a branch. Then it calculates ten outputs over five years on both, and checks that each input still counts as supplied and keeps its value, and that core still counts every recorded input as stored. This test also passes on the code before the fix.

The callers that read through the helpers, such as the bus fare, NI class 4 loss, carer benefit, childcare, Housing Benefit, PIP and energy price guarantee formulas, get a different answer only after one of the routes above has cached a value over the input.

Invariants

policyengine_uk/tests/test_supplied_inputs.py states them. The model covers every sequence of these steps: inputs set, values cached (calculated or not), arrays deleted and calculations run. Each step can act on a branch, on the branch it was made from or on the default branch, in memory or on disk.

1. Survival (model). supplied_input returns the input on the nearest branch that still stores one for the period, reading memory before disk. Otherwise it returns None. An input survives until something deletes it, or until another input or a cached value replaces it in the same tier. A value cached in memory over an input on disk leaves that input. A calculated value never replaces an input.
2. Agreement. supplied_input returns a value for a period exactly when supplied_input_periods lists that period, and the list runs from the earliest period.
3. Differential.
   • For every recorded input, the helpers count it as supplied exactly when core's Holder._stores_user_input does.
   • On core 3.33.1 and later, supplied_input returns what Simulation._get_recorded_input_array returns.
   • On core 3.33.2 and later, supplied_input_periods lists the periods that Simulation._get_set_input_periods lists.
4. Calculation. After calculation, every supplied value of every registered variable still counts as supplied and keeps its value.

Intended: a neutralised variable whose input survives reads as its default.

Tests

• policyengine_uk/tests/test_supplied_inputs.py has 53 tests:
  • one regression test for each of the 45 registered variables, with a value of the variable's own type (float, integer, boolean or enum) for its own period (a year, or a month for the four monthly variables);
  • other years' inputs still count;
  • an input on disk under a value cached in memory counts as supplied;
  • a value cached over an input on disk does not;
  • the engine never stores a calculated value over an input;
  • branch order;
  • a neutralised input;
  • the calculation test above;
  • a Hypothesis property test (100 examples, five explicit ones) of a model over a three-branch chain and both tiers.
• Hypothesis found an error in the model, not in the fix. From core 3.33, set_input first drops cached values that may depend on the input, so an input can go to disk where the model expected memory. The model now records the tier that holds each value, and an explicit example pins the case.
• Run locally at 71fb10c with policyengine-core 3.34.1 (uv sync --frozen --extra dev), -n 4 and a fresh --basetemp: this PR's test files and every test file that imports the helpers gave 590 passed. The 16 files: test_supplied_inputs.py, test_subsample.py, test_bus_fare_reforms.py, test_input_records.py, test_ni_class_4_profits_properties.py, test_gift_aid.py, test_housing_benefit_accommodation_dates.py, test_input_dataframe_export.py, test_capital_gains_projection.py, test_household_subset.py, aggregate_impact/test_aggregate_impact_childcare_provenance.py, aggregate_impact/test_aggregate_impact_guard.py, test_trading_allowance_claim_status_data_year.py, test_childcare_birthday_terms.py, test_benefit_cap_specified_benefits_properties.py and test_current_education_order.py.
• YAML policy tests at 71fb10c with core 3.34.1: the 250 files under policyengine_uk/tests/policy that name a variable in SUPPLIED_INPUT_VARIABLES gave 3,420 passed. They include bus_journeys, person_bus_fare_spending, loss_relief, ni_class_2 and ni_class_4_profits (68 passed on their own).
• policyengine_uk/tests/code_health at 71fb10c: 3,163 passed.
• Mutation check at 71fb10c, core 3.34.1, against test_supplied_inputs.py:
  • The helpers as they stood before the fix (reading through Holder._get_array_from_storage, with main's model-value check kept): 51 of 53 fail. The two that pass, test_a_calculated_value_is_never_stored_over_an_input and test_calculating_leaves_every_supplied_value_supplied, should pass before the fix too.
  • The tests catch each of six mutants of the fix:
    • no fall-back to the parent branch: 2 fail;
    • the periods helper left on the old rule: 50 fail;
    • ignoring the recorded tiers: 51 fail;
    • reading disk before memory: 1 fails (the Hypothesis test);
    • the periods helper ignoring model values: 2 fail; test_input_records.py, run alongside, catches none. A default single-person simulation stores model values of uc_LCWRA_element from 2026, and the mutant lists those years as supplied.
• uvx ruff@0.17.2 format --check ., uvx ruff@0.17.2 check ., uvx ruff@0.17.2 check --select F811,F821 policyengine_uk and git diff --check pass at 71fb10c.
• Not run locally: the full suite, or any test at 0e44f0988. CI runs the suite there.
• CI's aggregate impact report at 0e44f0988, merged into main (040e9a5f07 against 6fe91ff6e8, enhanced_frs_2024_25.h5, policyengine-uk-data 1.58.1, fiscal years 2025-26 to 2031-32), breaks no check and flags no moves, and no household's net income changes in any year. One check, sign:vat, fails on both sides, as it does on main.

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[juaristi22]

Reviewed at 5b4dc2143347b49226d06fc9e6421495da4e5cfe, using the stacked merge-base diff over #2265. No actionable findings in surviving-input storage tiers or affected consumers.

Both helpers use the same eligibility predicate as Core’s input-store checks, including recorded-empty locations, derived values, memory/disk tier order and overwritten child-branch inputs. The unchanged subsampling API retains its behavior.

Validation: all 104 tests in the five affected files passed, including the three-branch/two-tier properties, ordinary household net income and income tax, bus fare and NI loss consumers, and subsample rebuilds. Ruff formatting passed. Execution used Core3.33.2; I also compared the identical predicate in the pinned Core3.32.27 source. The documented #2265 merge dependency remains.

[MaxGhenis]

Picking this up for the UK hub. Reply here if you're mid-change and I'll stop.

---

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[MaxGhenis]

PR_TITLE.txt

Count only supplied inputs that are still stored in their tier

---

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[MaxGhenis]

PR_BODY.md

Fixes #2307
Reproducer: policyengine_uk/tests/test_supplied_inputs.py::test_a_value_cached_over_an_input_is_not_supplied
axiom: n/a: simulation infrastructure, no policy rule change

**Stacked on #2265.** #2265 adds `stored_supplied_value`, and this PR builds on it rather than adding a second copy. The PR targets #2265's branch (`fix-subsample-2254`). CI runs only for PRs into `main`, so it runs once GitHub moves this PR to `main`.

This branch merges `main` at 47a2817e2d57e6acbc08b76e09fde89fc27b81fa (merge commit 3bce60ef4c5e153a7c95a51341b0e3a85b8644f7). `main` had added model values (`set_model_value`), copied populations and 38 more variables in `SUPPLIED_INPUT_VARIABLES`, and requires policyengine-core 3.33.0 or later (`uv.lock` pins 3.34.1).

## What was wrong

`supplied_input` and `supplied_input_periods` treated a value cached over a supplied input as supplied. #2307 reproduces it: after `set_input` of 100 and `put_in_cache` of 999 for the same period, `supplied_input` returned `[999.]` and `supplied_input_periods` returned `[2025]`, while core's `Holder._stores_user_input` returned `False`. The same script on `main` at 47a2817e with policyengine-core 3.34.1 still prints `[999.]` and `[2025]`, and core's `Simulation._get_recorded_input_array` returns `None`.

## Why

Both helpers checked only two things: that core recorded the input (`Simulation._user_input_keys`), and that `Holder._get_array_from_storage` returned something. That method reads memory first, then disk, and does not ask whether the value it finds is the input. The record outlives a value cached over the input. `put_in_cache` stores over the input and takes that tier off the holder's record of where the input is (`Holder._user_input_storage`), but the `_user_input_keys` entry stays. So there were two wrong answers:

1. A value cached over the input in the same tier came back as supplied.
2. For an input stored on disk, with a value cached over it in memory, the helpers read memory and returned the cached value.

## What changes

- `supplied_input` reads through `stored_supplied_value` (from #2265). That reads a supplied value only from a tier in which core's `Holder._stores_user_input(period, branch_name, tier)` finds the input: a tier that the holder records the input in and that holds a value the engine did not calculate. Memory comes before disk.
- `supplied_input_periods` uses the same rule. It finds the tier without reading the value, which may be on disk. It reads the value only when the model stored one for the period (`set_model_value`), to tell the model's value from a supplied one, as `supplied_input` does. `stored_supplied_value` and the periods helper share a private `_supplied_value_storage`. What `stored_supplied_value` returns stays the same.
- Unchanged:
  - Branch order. `supplied_input` still looks at this branch first, then each branch it was made from, then the default branch. If a branch's input has gone, it reads the next one, as core's `_get_recorded_input_array` does.
  - Model values. Neither helper returns a value the model stored with `set_model_value` while it stays the stored value.
  - Neutralised variables. A neutralised variable whose input survives reads as its default.
  - `SUPPLIED_INPUT_VARIABLES` and its check.
- Not changed: `drop_missing_supplied_inputs`. It forgets a record whose value has gone from both tiers, the population-rebuild case (policyengine-core#605). It keeps a record whose input a cached value has replaced. That does no harm now: the helpers ignore such a record, and so does core's input export (`_stores_user_input`).

## Does this change results?

Not in normal calculation. The defect shows only when code stores a value with `Holder.put_in_cache` and its default `derived=False`, or with `Holder._set`.

- In policyengine-core 3.34.1, `Simulation` calls `put_in_cache` once, for each value it calculates, with `derived=True`.
- `put_in_cache` with `derived=True` stores nothing when the value `get_array` would read for that period is an input.
- Core's other writers store inputs: `set_input` and its period helpers, and the input replay in `_invalidate_all_caches`.
- The simulation dumper restores a dump into a new simulation, one value for each variable and period, so it stores nothing over an input either.
- policyengine-uk code outside its tests calls neither `put_in_cache` nor `Holder._set`.
- A code search of the PolicyEngine organisation found direct `put_in_cache` calls only in US code: one crfb-tob-impacts worker and two policyengine-us tests.

`test_calculating_leaves_every_supplied_value_supplied` executes this claim. It supplies all 45 variables in `SUPPLIED_INPUT_VARIABLES` for two years, each with a value of its own type for its own period, on the default branch, and one more input on a branch. Then it calculates ten outputs over five years on both, and checks that each input still counts as supplied and keeps its value, and that core still counts every recorded input as stored. This test also passes on the code before the fix.

The callers that read through the helpers, such as the bus fare, NI class 4 loss, carer benefit, childcare, Housing Benefit, PIP and energy price guarantee formulas, get a different answer only after one of the routes above has cached a value over the input.

## Invariants

`policyengine_uk/tests/test_supplied_inputs.py` states them. The model covers every sequence of these steps: inputs set, values cached (calculated or not), arrays deleted and calculations run. Each step can act on a branch, on the branch it was made from or on the default branch, in memory or on disk.

1. **Survival (model).** `supplied_input` returns the input on the nearest branch that still stores one for the period, reading memory before disk. Otherwise it returns `None`. An input survives until something deletes it, or until another input or a cached value replaces it in the same tier. A value cached in memory over an input on disk leaves that input. A calculated value never replaces an input.
2. **Agreement.** `supplied_input` returns a value for a period exactly when `supplied_input_periods` lists that period, and the list runs from the earliest period.
3. **Differential.**
   - For every recorded input, the helpers count it as supplied exactly when core's `Holder._stores_user_input` does.
   - On core 3.33.1 and later, `supplied_input` returns what `Simulation._get_recorded_input_array` returns.
   - On core 3.33.2 and later, `supplied_input_periods` lists the periods that `Simulation._get_set_input_periods` lists.
4. **Calculation.** After calculation, every supplied value of every registered variable still counts as supplied and keeps its value.

Intended: a neutralised variable whose input survives reads as its default.

## Tests

- `policyengine_uk/tests/test_supplied_inputs.py` has 53 tests:
  - one regression test for each of the 45 registered variables, with a value of the variable's own type (float, integer, boolean or enum) for its own period (a year, or a month for the four monthly variables);
  - other years' inputs still count;
  - an input on disk under a value cached in memory counts as supplied;
  - a value cached over an input on disk does not;
  - the engine never stores a calculated value over an input;
  - branch order;
  - a neutralised input;
  - the calculation test above;
  - a Hypothesis property test (100 examples, five explicit ones) of a model over a three-branch chain and both tiers.
- Hypothesis found an error in the model, not in the fix. From core 3.33, `set_input` first drops cached values that may depend on the input, so an input can go to disk where the model expected memory. The model now records the tier that holds each value, and an explicit example pins the case.
- Run locally at 71fb10ca1c332341137bce7cafc1f0b46c3d0213 with policyengine-core 3.34.1 (`uv sync --frozen --extra dev`), `-n 4` and a fresh `--basetemp`: this PR's test files and every test file that imports the helpers gave 590 passed. The 16 files: `test_supplied_inputs.py`, `test_subsample.py`, `test_bus_fare_reforms.py`, `test_input_records.py`, `test_ni_class_4_profits_properties.py`, `test_gift_aid.py`, `test_housing_benefit_accommodation_dates.py`, `test_input_dataframe_export.py`, `test_capital_gains_projection.py`, `test_household_subset.py`, `aggregate_impact/test_aggregate_impact_childcare_provenance.py`, `aggregate_impact/test_aggregate_impact_guard.py`, `test_trading_allowance_claim_status_data_year.py`, `test_childcare_birthday_terms.py`, `test_benefit_cap_specified_benefits_properties.py` and `test_current_education_order.py`.
- YAML policy tests at 71fb10ca with core 3.34.1: the 250 files under `policyengine_uk/tests/policy` that name a variable in `SUPPLIED_INPUT_VARIABLES` gave 3,420 passed. They include `bus_journeys`, `person_bus_fare_spending`, `loss_relief`, `ni_class_2` and `ni_class_4_profits` (68 passed on their own).
- `policyengine_uk/tests/code_health` at 71fb10ca: 3,163 passed.
- Mutation check at 71fb10ca, core 3.34.1, against `test_supplied_inputs.py`:
  - The helpers as they stood before the fix (reading through `Holder._get_array_from_storage`, with `main`'s model-value check kept): 51 of 53 fail. The two that pass, `test_a_calculated_value_is_never_stored_over_an_input` and `test_calculating_leaves_every_supplied_value_supplied`, should pass before the fix too.
  - The tests catch each of six mutants of the fix:
    - no fall-back to the parent branch: 2 fail;
    - the periods helper left on the old rule: 50 fail;
    - ignoring the recorded tiers: 51 fail;
    - reading disk before memory: 1 fails (the Hypothesis test);
    - the periods helper ignoring model values: 2 fail; `test_input_records.py`, run alongside, catches none. A default single-person simulation stores model values of `uc_LCWRA_element` from 2026, and the mutant lists those years as supplied.
- `uvx ruff@0.17.2 format --check .`, `uvx ruff@0.17.2 check .`, `uvx ruff@0.17.2 check --select F811,F821 policyengine_uk` and `git diff --check` pass at 71fb10ca.
- Not run locally: the full suite. CI runs it once this PR moves to `main`.

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[MaxGhenis]

Ready for hub review

Head: 71fb10ca1c332341137bce7cafc1f0b46c3d0213 on claude/merge-main-pr-2308-4p6qfw. It branches from this PR's head 5b4dc2143347b49226d06fc9e6421495da4e5cfe. The harness pins pushes to claude/..., so I did not push to fix-supplied-input-tiers. No PR has this branch as its head, so no CI has run.

Commits on top of 5b4dc21:

1. 3bce60ef merges main at 47a2817e2d57e6acbc08b76e09fde89fc27b81fa. main had moved past the brief's 95dfc62f only by Count Maternity Allowance in the benefit cap #2811 (Maternity Allowance in the benefit cap). That change touches neither conflicted file, and git merge-tree gave the same two conflicts against both commits.
2. 42414bd5 asks core's Holder._stores_user_input which tier holds the input.
3. e02d116c generalises the tests to main's 45 registered variables.
4. 71fb10ca renames the changelog fragment to changelog.d/2307.fixed.md and drops its leading list marker.

Open findings

None. The PR has one review, 5638137428 by juaristi22 at 5b4dc21: APPROVED, "No actionable findings". It has no inline review comments and no issue comments besides my pick-up note. The approval predates the merge.

Conflict resolutions

• policyengine_uk/simulation.py:85-93: an import-block conflict only. I kept this branch's subsample_simulation import (Give UK simulations a working subsample #2265) and main's built_from_data, input_dataframe and measurement_branches imports. Git merged the rest of the file cleanly.
• policyengine_uk/utils/supplied_inputs.py:
  • Module docstring (lines 1-44): I kept main's paragraphs on rebuilds (copy_other_populations, keep_population_records) and model values (set_model_value), this branch's paragraph on tiers, and the supplied_input_arrays line from Give UK simulations a working subsample #2265.
  • supplied_input_periods (around line 160): main read the value twice through _get_array_from_storage to exclude model values. This branch checks the tier without reading. Resolution: a new _supplied_without_reading (around line 305) finds the tier through _supplied_value_storage and reads the value only when _model_values holds a value for that key, then applies main's _is_model_value. This keeps both intents.
  • supplied_input (around line 230): Git merged it cleanly. It reads through stored_supplied_value, then main's model-value check returns None, then the neutralised default.
  • Tail of the file: I kept Give UK simulations a working subsample #2265's supplied_input_arrays and stored_supplied_value, this PR's _supplied_value_storage, and all of main's model-value and population-copy helpers.
• Where main now does what the PR did: main requires policyengine-core 3.33.0 or later. From that version, Holder._stores_user_input(period, branch_name, storage_name) checks one tier. I diffed the 3.33.0 and 3.34.1 sources: it and holders.helpers._is_input and get_stored_input match. So commit 42414bd5 drops this PR's copy of the per-tier rule from _supplied_value_storage (supplied_inputs.py:291-303) and calls core's method. I kept stored_supplied_value rather than switching to core's get_stored_input. Core's helper differs in three ways: it requires the key in _user_input_keys, it counts any stored value as an input when the simulation has no record, and it writes _user_input_storage (_seed_input_storage). subsample.py and the tests call stored_supplied_value directly.
• main still has the supplied_input and supplied_input_periods count a value cached over a supplied input as supplied #2307 bug. I ran supplied_input and supplied_input_periods count a value cached over a supplied input as supplied #2307's script on main at 47a2817 with core 3.34.1, and it printed [999.] and [Period(2025)], while _get_recorded_input_array returned None. So the PR's fix is still needed.

Tests changed by the merge

main grew SUPPLIED_INPUT_VARIABLES from 7 to 45 variables, among them booleans, enums, integers and four monthly variables. At the merge commit, 14 tests failed:

• 13 of the parametrised test_a_value_cached_over_an_input_is_not_supplied, which stored a float for a year. Enums raised Unsupported array dtype: float64.
• test_calculating_leaves_every_supplied_value_supplied, which asserted that a hard-coded table of 7 variables equals the registered set.

Commit e02d116c adds stored_period and value_of_type (test_supplied_inputs.py:101-125), which store a value of each variable's own type for its own period. The calculation test now supplies all 45 variables. The hasattr(..., "_get_recorded_input_array") guards stay: core 3.33.0, which pyproject.toml still allows, lacks that method.

Tests run (all at 71fb10ca, core 3.34.1, uv sync --frozen --extra dev)

• Python, -n 4, fresh --basetemp: 590 passed across this PR's files and every test file that imports the helpers. The 16 files are test_supplied_inputs.py (53), test_subsample.py, test_bus_fare_reforms.py, test_input_records.py, test_ni_class_4_profits_properties.py, test_gift_aid.py, test_housing_benefit_accommodation_dates.py, test_input_dataframe_export.py, test_capital_gains_projection.py, test_household_subset.py, aggregate_impact/test_aggregate_impact_childcare_provenance.py, aggregate_impact/test_aggregate_impact_guard.py, test_trading_allowance_claim_status_data_year.py, test_childcare_birthday_terms.py, test_benefit_cap_specified_benefits_properties.py and test_current_education_order.py.
• YAML: 3,420 passed across the 250 policy files that name a registered variable. The five files the PR body names gave 68 passed on their own.
• policyengine_uk/tests/code_health: 3,163 passed.
• uvx ruff@0.17.2 format --check ., check . and check --select F811,F821 policyengine_uk: pass. git diff --check origin/main HEAD: clean.
• .github/check_changelog_fragments.py --base origin/main --head HEAD: OK. It warns only about Give UK simulations a working subsample #2265's fix-subsample-2254.fixed.md list marker, which I left alone.
• .github/check_fix_pr.py on the final title and body with head 71fb10ca: PASS. It found 2 changed executable tests against main, and 504 against the current fix-subsample-2254.

Mutation and revert checks (repeated because the merge changed the code they cover)

All ran against test_supplied_inputs.py at 71fb10ca:

• Pre-fix helpers (_get_array_from_storage, keeping main's model-value check): 51 of 53 fail. The two calculation tests pass, as before.
• No fall-back to the parent branch: 2 fail.
• The periods helper on the old rule: 50 fail.
• Ignoring the recorded tiers: 51 fail.
• Reading disk before memory: 1 fails (the Hypothesis test).
• New, for the merged code: the periods helper ignoring model values. 2 fail: the uc_LCWRA_element regression case and the calculation test. A default single-person simulation stores model values of uc_LCWRA_element from 2026 onwards. test_input_records.py catches none of these mutants.

Skipped and why

• The full suite, which CI runs.
• Core 3.32.27 runs: main now requires 3.33.0 or later.
• No law needed: this is simulation infrastructure.
• No survey-data tests.

Judgement calls

• I merged main at 47a2817e, not the brief's 95dfc62f, because it was current and the extra commits touch neither conflicted file.
• I left the stack note in the body. Give UK simulations a working subsample #2265 is still open and fix-subsample-2254 is still the base. That base gained four commits after this PR's head (9a91736f "Preserve neutralised inputs when subsampling", 74b0c65d, 1fbfa6c7, e4c54d7f), and this branch does not include them. Its last merge of main (fc537e4e) predates 47a2817e. Against that base, GitHub's diff will show main's changes too, until Give UK simulations a working subsample #2265 merges main or this PR moves to main.
• I renamed the fragment from fix-supplied-input-tiers.fixed.md to 2307.fixed.md. Towncrier's issue_format is empty, so the text keeps (#2307).

Sentences in PR_BODY.md that carry a CI figure

None. Every count in the body comes from a local run labelled 71fb10ca. The only CI sentences are "CI runs only for PRs into main, so it runs once GitHub moves this PR to main." and "Not run locally: the full suite. CI runs it once this PR moves to main."

---

Generated by Claude Code

[github-actions]

Aggregate impact on certified data: pass

Base 040e9a5f07 against head 6fe91ff6e8, both on enhanced_frs_2024_25.h5 (policyengine-uk-data 1.58.1, sha256 056e80fd8e91), fiscal years 2025-26 to 2031-32. Each year is a full microsimulation run on each side.

Checks: 0 broken by this change, 1 failing on both sides, 0 fixed. Moves flagged for review: 0 (thresholds in report_spec.yaml; a flag does not fail the job).

Workflow run and full report

Notes

• In the years a figure from fewer than 10 records is suppressed (spending.disabled_students_allowance), every total containing it, and the decile incomes, are rebuilt from their other components, so no published total includes it. Those totals are marked †. A change is withheld where the two sides leave out different figures and can't be lined up.

Moves flagged for review

None.

Spending by benefit and service

Measure	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Disabled Students' Allowance	suppressed	suppressed	suppressed	suppressed	suppressed	suppressed	suppressed

Caseloads

Measure	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Disabled Students' Allowance	suppressed	suppressed	suppressed	suppressed	suppressed	suppressed	suppressed

Household net income by decile

No household's net income changes in any year.

No change in any year: receipts by tax head; government balance, each component counted once; model totals; household income totals; population; poverty rates; people in poverty; inequality; mean household net income in each side's own deciles; standard reform costings (change in gov_balance); standard reforms: change in each reform's target.

Checks failing on both base and head (1)

• VAT excluding private school fees is never negative (sign:vat): 2025-26: 76 units below zero, a weighted £-53,888,684 in total; 2026-27: 76 units below zero, a weighted £-55,777,260 in total; 2027-28: 76 units below zero, a weighted £-57,727,917 in total

Counted-once check

Each of 92 components was raised by £1 per unit in 2026-27, and every head of its totals was read household by household: its own head must rise by exactly £1, no other tax head may move, no other benefit may rise, and the model's own total must move by what its heads moved. A head that breaks a rule is measured again twice: with every other head held at its baseline value, and with every other head held at its value after the first £1 while the component rises again. It fails where either still shows the response. 0 failed; 0 were skipped.

• widowed_parents_allowance: pension_credit responds only through other heads in fewer than 10 households (other heads that moved there: carers_allowance; gov_spending; not a failure)
• widowed_parents_allowance: pension_credit responds only through other heads in fewer than 10 households (other heads that moved there: carers_allowance; household_benefits; not a failure)

Provenance

Side	Commit	Runtime	Environment hash	Partition hash	Time
base	main 040e9a5f07	uk 2.175.4 (files 889511591b1d), core 3.34.1, py 3.13.18 aarch64	b1e13a3ca1b7	3bcfb3473960	2448.13s
head	#2308 merged into main 6fe91ff6e8	uk 2.175.4 (files 4bf9253e5a62), core 3.34.1, py 3.13.18 aarch64	b1e13a3ca1b7	3bcfb3473960	2512.08s

Dataset: hf://policyengine/policyengine-uk-data-private/enhanced_frs_2024_25.h5@2526edbbb687a3b54dbb11272e5389e4b62d2ac2, sha256 056e80fd8e9151d78f432a25cde863340baee81304c6216a37fb575ce8563784 (verified on both sides), policyengine-uk-data 1.58.1.

Receipts by tax head: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Final charge on cash interest in non-cash ISAs	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Lifetime ISA withdrawal charge	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Income tax	£294.46bn	£315.23bn	£335.82bn	£351.28bn	£366.96bn	£385.36bn	£399.99bn
National Insurance (employee and self-employed)	£51.70bn	£54.14bn	£56.13bn	£57.73bn	£59.76bn	£61.64bn	£63.51bn
National Insurance (employer)	£148.71bn	£155.37bn	£160.88bn	£165.09bn	£172.06bn	£177.36bn	£182.57bn
Employer NI change borne by capital	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Employer NI change borne by consumers	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Capital gains tax	£12.60bn	£13.15bn	£13.60bn	£14.11bn	£14.67bn	£15.24bn	£15.80bn
Student loan repayments	£7.82bn	£8.13bn	£8.39bn	£8.58bn	£8.79bn	£9.04bn	£9.29bn
VAT excluding private school fees	£249.37bn	£256.87bn	£266.33bn	£272.70bn	£278.97bn	£285.24bn	£291.59bn
Change in VAT from its baseline	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
VAT on private school fees	£1.95bn	£2.01bn	£2.09bn	£2.14bn	£2.20bn	£2.26bn	£2.31bn
Change in private school VAT from its baseline	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Fuel duties	£24.71bn	£24.13bn	£26.00bn	£26.83bn	£26.51bn	£25.78bn	£24.63bn
Alcohol duties	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Tobacco duties	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Vehicle excise duties	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Betting and gaming duties	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
TV licence fee	£4.26bn	£4.40bn	£4.41bn	£4.42bn	£4.43bn	£4.44bn	£4.45bn
Council tax	£49.21bn	£52.16bn	£54.89bn	£57.95bn	£61.16bn	£64.47bn	£67.91bn
High value council tax surcharge	£0.00bn	£0.00bn	£0.00bn	£0.48bn	£0.49bn	£0.50bn	£0.51bn
Northern Ireland domestic rates	£0.55bn	£0.58bn	£0.60bn	£0.63bn	£0.66bn	£0.69bn	£0.72bn
Business rates	£34.68bn	£36.20bn	£38.00bn	£39.46bn	£42.27bn	£43.25bn	£44.29bn
Stamp duty land tax on the household's own purchases	£6.88bn	£7.32bn	£7.66bn	£8.06bn	£8.47bn	£8.91bn	£9.35bn
Stamp duty land tax paid by companies	£4.72bn	£4.57bn	£5.29bn	£6.03bn	£6.37bn	£6.92bn	£7.45bn
Land transaction tax (Wales)	£0.07bn	£0.08bn	£0.08bn	£0.09bn	£0.10bn	£0.10bn	£0.11bn
Land and buildings transaction tax (Scotland)	£0.31bn	£0.32bn	£0.33bn	£0.35bn	£0.36bn	£0.38bn	£0.40bn
Unspecified tax change borne by capital	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Unspecified tax change borne by consumers	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Wealth tax	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Wealth tax excluding the main residence	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Land value tax	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Carbon tax	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn

Spending by benefit and service: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Lifetime ISA bonus	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
State Pension	£121.68bn	£125.92bn	£126.72bn	£129.48bn	£132.98bn	£136.65bn	£140.41bn
Pension Credit	£6.21bn	£6.46bn	£6.68bn	£6.82bn	£6.89bn	£7.07bn	£7.22bn
Winter Fuel Payment	£1.86bn	£1.85bn	£1.79bn	£1.77bn	£1.78bn	£1.78bn	£1.78bn
Pension Age Winter Heating Payment (Scotland)	£0.19bn	£0.20bn	£0.20bn	£0.21bn	£0.21bn	£0.22bn	£0.22bn
Universal Credit	£75.48bn	£81.56bn	£84.02bn	£86.07bn	£87.22bn	£88.76bn	£89.38bn
Housing Benefit	£8.56bn	£8.51bn	£8.83bn	£9.05bn	£9.28bn	£9.56bn	£9.83bn
Council Tax Reduction	£2.07bn	£2.20bn	£2.32bn	£2.45bn	£2.59bn	£2.73bn	£2.87bn
Employment and Support Allowance (income-related)	£0.79bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Employment and Support Allowance (contribution-based)	£5.20bn	£5.37bn	£5.56bn	£5.69bn	£5.82bn	£5.95bn	£6.09bn
Jobseeker's Allowance (income-based)	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Jobseeker's Allowance (contribution-based)	£0.29bn	£0.30bn	£0.31bn	£0.31bn	£0.32bn	£0.33bn	£0.34bn
Income Support	£0.11bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Working Tax Credit	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Child Tax Credit	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Incapacity Benefit	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Personal Independence Payment	£26.95bn	£28.03bn	£29.05bn	£30.09bn	£30.75bn	£31.51bn	£32.21bn
Disability Living Allowance	£7.49bn	£7.79bn	£8.07bn	£8.36bn	£8.55bn	£8.76bn	£8.95bn
Attendance Allowance	£8.68bn	£9.03bn	£9.36bn	£9.69bn	£9.90bn	£10.15bn	£10.38bn
Carer's Allowance	£4.48bn	£4.66bn	£4.83bn	£5.00bn	£5.11bn	£5.27bn	£5.42bn
Carer Support Payment (Scotland)	£0.31bn	£0.32bn	£0.33bn	£0.34bn	£0.35bn	£0.36bn	£0.37bn
Carer's Allowance Supplement (Scotland)	£0.00bn	£0.04bn	£0.04bn	£0.05bn	£0.05bn	£0.05bn	£0.05bn
Severe Disablement Allowance	£0.03bn	£0.03bn	£0.03bn	£0.03bn	£0.03bn	£0.03bn	£0.03bn
Industrial Injuries Disablement Benefit	£0.50bn	£0.52bn	£0.54bn	£0.55bn	£0.56bn	£0.58bn	£0.59bn
Armed Forces Compensation Scheme	£0.61bn	£0.63bn	£0.65bn	£0.66bn	£0.68bn	£0.69bn	£0.71bn
War Widow's or Widower's Pension	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Child Benefit	£16.19bn	£16.82bn	£17.39bn	£18.00bn	£18.39bn	£18.84bn	£19.25bn
Scottish Child Payment	£0.49bn	£0.52bn	£0.53bn	£0.55bn	£0.56bn	£0.57bn	£0.56bn
Two Child Limit Payment (Scotland, counterfactual)	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Healthy Start vouchers	£0.05bn	£0.05bn	£0.05bn	£0.05bn	£0.05bn	£0.05bn	£0.05bn
Maternity Allowance	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Statutory Maternity Pay	£3.30bn	£3.41bn	£3.54bn	£3.62bn	£3.70bn	£3.78bn	£3.87bn
Statutory Paternity Pay	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Statutory Sick Pay	£1.12bn	£1.16bn	£1.20bn	£1.23bn	£1.26bn	£1.29bn	£1.32bn
Sure Start Maternity Grant	£0.01bn	£0.01bn	£0.01bn	£0.01bn	£0.01bn	£0.01bn	£0.01bn
Bereavement Support Payment	£0.67bn	£0.69bn	£0.71bn	£0.73bn	£0.75bn	£0.76bn	£0.78bn
Widowed Parent's Allowance	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Tax-Free Childcare	£0.56bn	£0.57bn	£0.57bn	£0.58bn	£0.60bn	£0.61bn	£0.59bn
Extended childcare entitlement	£2.99bn	£3.50bn	£3.59bn	£3.71bn	£3.78bn	£3.86bn	£3.93bn
Universal childcare entitlement	£2.06bn	£2.22bn	£2.29bn	£2.37bn	£2.43bn	£2.48bn	£2.53bn
Targeted childcare entitlement	£0.50bn	£0.51bn	£0.52bn	£0.54bn	£0.55bn	£0.57bn	£0.56bn
Childcare Offer for Wales	£0.26bn	£0.28bn	£0.28bn	£0.29bn	£0.30bn	£0.31bn	£0.32bn
Care to Learn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Childcare Grant	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Parents' Learning Allowance	£0.20bn	£0.20bn	£0.20bn	£0.20bn	£0.20bn	£0.20bn	£0.20bn
Adult Dependants' Grant	£0.06bn	£0.06bn	£0.04bn	£0.04bn	£0.04bn	£0.04bn	£0.04bn
Travel Grant	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Disabled Students' Allowance	suppressed	suppressed	suppressed	suppressed	suppressed	suppressed	suppressed
16 to 19 Bursary Fund	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
NHS spending	£203.89bn	£204.30bn	£204.56bn	£204.91bn	£205.34bn	£205.85bn	£206.35bn
State education spending	£0.02bn	£0.02bn	£0.02bn	£0.02bn	£0.02bn	£0.02bn	£0.02bn
Transport subsidy spending	£25.05bn	£25.10bn	£25.14bn	£25.18bn	£25.23bn	£25.30bn	£25.36bn
Cost-of-living support payment	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Energy Bills Rebate	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Household Energy Payment	£0.00bn	£2.11bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Energy Price Guarantee subsidy	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Basic income	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Disability basic income	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Other public spending budget change	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn

Caseloads: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Lifetime ISA bonus	0k	0k	0k	0k	0k	0k	0k
State Pension	11,264k	11,145k	10,819k	10,700k	10,723k	10,750k	10,776k
Pension Credit	1,489k	1,484k	1,476k	1,454k	1,452k	1,457k	1,466k
Winter Fuel Payment	7,844k	7,783k	7,473k	7,375k	7,391k	7,409k	7,427k
Pension Age Winter Heating Payment (Scotland)	803k	802k	800k	797k	799k	801k	802k
Universal Credit	6,342k	6,418k	6,408k	6,369k	6,363k	6,343k	6,295k
Housing Benefit	1,249k	1,182k	1,181k	1,164k	1,164k	1,166k	1,168k
Council Tax Reduction	3,180k	3,199k	3,205k	3,218k	3,233k	3,244k	3,251k
Employment and Support Allowance (income-related)	71k	0k	0k	0k	0k	0k	0k
Employment and Support Allowance (contribution-based)	719k	720k	721k	722k	724k	726k	728k
Jobseeker's Allowance (income-based)	0k	0k	0k	0k	0k	0k	0k
Jobseeker's Allowance (contribution-based)	67k	67k	67k	67k	67k	68k	68k
Income Support	25k	0k	0k	0k	0k	0k	0k
Working Tax Credit	0k	0k	0k	0k	0k	0k	0k
Child Tax Credit	0k	0k	0k	0k	0k	0k	0k
Incapacity Benefit	0k	0k	0k	0k	0k	0k	0k
Personal Independence Payment	3,567k	3,575k	3,579k	3,585k	3,593k	3,602k	3,611k
Disability Living Allowance	1,291k	1,294k	1,296k	1,298k	1,300k	1,304k	1,307k
Attendance Allowance	1,695k	1,698k	1,700k	1,703k	1,707k	1,711k	1,715k
Carer's Allowance	1,034k	1,037k	1,038k	1,040k	1,042k	1,060k	1,062k
Carer Support Payment (Scotland)	71k	71k	71k	72k	72k	72k	72k
Carer's Allowance Supplement (Scotland)	0k	71k	71k	72k	72k	72k	72k
Severe Disablement Allowance	4k	4k	4k	4k	4k	4k	4k
Industrial Injuries Disablement Benefit	137k	137k	137k	138k	138k	138k	139k
Armed Forces Compensation Scheme	93k	93k	94k	94k	94k	94k	94k
War Widow's or Widower's Pension	0k	0k	0k	0k	0k	0k	0k
Child Benefit	8,123k	8,120k	8,120k	8,130k	8,145k	8,161k	8,178k
Scottish Child Payment	351k	352k	352k	353k	350k	348k	337k
Two Child Limit Payment (Scotland, counterfactual)	0k	0k	0k	0k	0k	0k	0k
Healthy Start vouchers	200k	200k	200k	201k	201k	201k	202k
Maternity Allowance	0k	0k	0k	0k	0k	0k	0k
Statutory Maternity Pay	333k	333k	334k	334k	335k	336k	337k
Statutory Paternity Pay	0k	0k	0k	0k	0k	0k	0k
Statutory Sick Pay	181k	182k	182k	182k	182k	183k	183k
Sure Start Maternity Grant	26k	26k	26k	26k	26k	26k	26k
Bereavement Support Payment	98k	98k	98k	98k	98k	99k	99k
Widowed Parent's Allowance	0k	0k	0k	0k	0k	0k	0k
Tax-Free Childcare	1,043k	1,027k	1,014k	1,009k	1,011k	1,009k	993k
Extended childcare entitlement	795k	800k	796k	797k	798k	798k	792k
Universal childcare entitlement	1,071k	1,072k	1,072k	1,073k	1,076k	1,079k	1,074k
Targeted childcare entitlement	165k	156k	154k	154k	155k	155k	150k
Childcare Offer for Wales	39k	39k	39k	39k	39k	39k	39k
Care to Learn	0k	0k	0k	0k	0k	0k	0k
Childcare Grant	0k	0k	0k	0k	0k	0k	0k
Parents' Learning Allowance	98k	98k	98k	99k	99k	99k	99k
Adult Dependants' Grant	18k	18k	12k	12k	12k	12k	12k
Travel Grant	0k	0k	0k	0k	0k	0k	0k
Disabled Students' Allowance	suppressed	suppressed	suppressed	suppressed	suppressed	suppressed	suppressed
16 to 19 Bursary Fund	0k	0k	0k	0k	0k	0k	0k
Cost-of-living support payment	0k	0k	0k	0k	0k	0k	0k
Energy Bills Rebate	0k	0k	0k	0k	0k	0k	0k
Household Energy Payment	0k	21,065k	0k	0k	0k	0k	0k
Energy Price Guarantee subsidy	0k	0k	0k	0k	0k	0k	0k
Basic income	0k	0k	0k	0k	0k	0k	0k
Disability basic income	0k	0k	0k	0k	0k	0k	0k

Government balance, each component counted once: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Government receipts, each component once	£892.00bn	£934.66bn	£980.50bn	£1,015.93bn	£1,054.24bn	£1,091.56bn	£1,124.89bn
Government spending	£528.93bn †	£544.94bn †	£549.99bn †	£558.68bn †	£566.30bn †	£575.00bn †	£582.59bn †
Government balance, each receipt once	£363.07bn †	£389.72bn †	£430.51bn †	£457.24bn †	£487.94bn †	£516.56bn †	£542.31bn †
Benefits in household_benefits but not in gov_spending	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn

Model totals: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
gov_tax	£892.00bn	£934.66bn	£980.50bn	£1,015.93bn	£1,054.24bn	£1,091.56bn	£1,124.89bn
household_tax	£491.97bn	£520.41bn	£551.21bn	£576.00bn	£601.00bn	£626.69bn	£648.42bn
pre_budget_change_household_tax	£484.15bn	£512.28bn	£542.82bn	£566.95bn	£591.72bn	£617.16bn	£638.61bn
gov_spending	£528.93bn †	£544.94bn †	£549.99bn †	£558.68bn †	£566.30bn †	£575.00bn †	£582.59bn †
household_benefits	£528.93bn †	£544.94bn †	£549.99bn †	£558.68bn †	£566.30bn †	£575.00bn †	£582.59bn †
gov_balance	£363.07bn †	£389.72bn †	£430.51bn †	£457.24bn †	£487.94bn †	£516.56bn †	£542.31bn †

Household income totals: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Household market income	£1,637.96bn	£1,702.77bn	£1,757.35bn	£1,806.41bn	£1,855.97bn	£1,912.43bn	£1,970.44bn
Household net income	£1,636.24bn †	£1,687.10bn †	£1,714.68bn †	£1,746.67bn †	£1,777.79bn †	£1,816.07bn †	£1,858.68bn †
Household net income (HBAI definition)	£1,449.13bn	£1,499.11bn	£1,530.09bn	£1,564.35bn	£1,596.99bn	£1,634.64bn	£1,675.60bn

Population: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
People	69,245k	69,383k	69,473k	69,592k	69,738k	69,912k	70,080k
Benefit units	35,110k	35,181k	35,226k	35,286k	35,360k	35,449k	35,534k
Households	31,046k	31,108k	31,149k	31,201k	31,267k	31,345k	31,420k

Poverty rates: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Absolute poverty, before housing costs: everyone	16.3%	15.5%	16.4%	16.3%	16.5%	16.5%	16.6%
Absolute poverty, before housing costs: children	24.7%	22.1%	23.3%	22.9%	23.1%	23.2%	23.5%
Absolute poverty, before housing costs: working-age adults	14.1%	13.8%	14.7%	14.7%	14.8%	14.8%	15.0%
Absolute poverty, before housing costs: pensioners	13.7%	13.4%	14.0%	13.8%	14.0%	14.0%	13.9%
Absolute poverty, after housing costs: everyone	21.6%	21.1%	22.0%	22.6%	22.9%	23.1%	23.5%
Absolute poverty, after housing costs: children	33.3%	31.3%	32.3%	32.5%	32.9%	33.4%	34.2%
Absolute poverty, after housing costs: working-age adults	19.9%	19.8%	20.8%	21.6%	21.9%	22.0%	22.3%
Absolute poverty, after housing costs: pensioners	12.7%	12.4%	13.2%	13.2%	13.3%	13.4%	13.6%
Relative poverty, before housing costs: everyone	17.0%	16.0%	16.4%	16.3%	16.4%	16.3%	16.6%
Relative poverty, before housing costs: children	25.9%	22.9%	23.3%	22.9%	23.0%	22.9%	23.5%
Relative poverty, before housing costs: working-age adults	14.5%	14.1%	14.6%	14.7%	14.7%	14.7%	15.0%
Relative poverty, before housing costs: pensioners	14.5%	14.1%	14.0%	13.8%	13.8%	13.9%	13.9%
Relative poverty, after housing costs: everyone	21.5%	21.0%	21.2%	21.3%	21.3%	21.5%	21.7%
Relative poverty, after housing costs: children	33.1%	31.1%	31.1%	31.0%	31.1%	31.2%	31.8%
Relative poverty, after housing costs: working-age adults	19.9%	19.8%	20.2%	20.4%	20.5%	20.6%	20.8%
Relative poverty, after housing costs: pensioners	12.5%	12.4%	12.2%	11.8%	11.7%	11.8%	12.1%

People in poverty: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Absolute poverty, before housing costs: everyone	11,277k	10,784k	11,408k	11,373k	11,482k	11,521k	11,657k
Absolute poverty, before housing costs: children	3,688k	3,314k	3,496k	3,445k	3,480k	3,502k	3,549k
Absolute poverty, before housing costs: working-age adults	5,965k	5,895k	6,311k	6,366k	6,423k	6,434k	6,524k
Absolute poverty, before housing costs: pensioners	1,624k	1,575k	1,601k	1,562k	1,579k	1,585k	1,584k
Absolute poverty, after housing costs: everyone	14,944k	14,607k	15,318k	15,729k	15,946k	16,150k	16,440k
Absolute poverty, after housing costs: children	4,975k	4,682k	4,837k	4,888k	4,945k	5,040k	5,179k
Absolute poverty, after housing costs: working-age adults	8,463k	8,465k	8,976k	9,348k	9,496k	9,588k	9,715k
Absolute poverty, after housing costs: pensioners	1,506k	1,461k	1,506k	1,494k	1,506k	1,522k	1,546k
Relative poverty, before housing costs: everyone	11,750k	11,088k	11,394k	11,363k	11,422k	11,423k	11,657k
Relative poverty, before housing costs: children	3,872k	3,423k	3,496k	3,443k	3,466k	3,454k	3,549k
Relative poverty, before housing costs: working-age adults	6,159k	6,014k	6,304k	6,361k	6,392k	6,393k	6,524k
Relative poverty, before housing costs: pensioners	1,719k	1,651k	1,594k	1,560k	1,564k	1,576k	1,584k
Relative poverty, after housing costs: everyone	14,864k	14,560k	14,740k	14,811k	14,883k	15,023k	15,241k
Relative poverty, after housing costs: children	4,944k	4,660k	4,660k	4,662k	4,679k	4,707k	4,805k
Relative poverty, after housing costs: working-age adults	8,431k	8,444k	8,687k	8,823k	8,880k	8,974k	9,067k
Relative poverty, after housing costs: pensioners	1,489k	1,456k	1,393k	1,327k	1,325k	1,342k	1,369k

Inequality: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Gini coefficient, equivalised HBAI income before housing costs	0.3078	0.3051	0.3057	0.3056	0.3061	0.3067	0.3083

Mean household net income in each side's own deciles: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Decile 1: mean household_net_income per household	£17,681 †	£18,010 †	£17,918 †	£18,160 †	£18,301 †	£18,547 †	£18,732 †
Decile 2: mean household_net_income per household	£27,942 †	£29,024 †	£28,623 †	£29,004 †	£29,287 †	£29,699 †	£30,089 †
Decile 3: mean household_net_income per household	£34,316 †	£35,426 †	£36,075 †	£36,523 †	£36,995 †	£37,682 †	£38,154 †
Decile 4: mean household_net_income per household	£38,934 †	£40,687 †	£41,716 †	£42,770 †	£43,423 †	£44,111 †	£44,446 †
Decile 5: mean household_net_income per household	£43,235 †	£45,555 †	£46,034 †	£46,930 †	£47,714 †	£48,578 †	£50,274 †
Decile 6: mean household_net_income per household	£47,931 †	£49,240 †	£50,932 †	£51,984 †	£52,963 †	£53,976 †	£54,714 †
Decile 7: mean household_net_income per household	£55,659 †	£56,577 †	£57,445 †	£57,649 †	£58,750 †	£59,668 †	£61,096 †
Decile 8: mean household_net_income per household	£68,784 †	£70,805 †	£71,866 †	£73,514 †	£73,888 †	£75,324 †	£77,180 †
Decile 9: mean household_net_income per household	£78,889 †	£81,012 †	£80,859 †	£82,645 †	£85,463 †	£86,945 †	£89,508 †
Decile 10: mean household_net_income per household	£116,861 †	£120,160 †	£124,545 †	£126,419 †	£125,752 †	£128,367 †	£130,693 †

Standard reform costings (change in gov_balance): head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Raise basic rate by 1pp	£6.41bn	£6.66bn	£6.63bn	£6.85bn	£7.03bn	£7.25bn	£7.49bn
Raise higher rate by 1pp	£3.61bn	£3.87bn	£4.00bn	£4.22bn	£4.44bn	£4.71bn	£4.83bn
Raise personal allowance by ~800GBP/year	£-3.81bn	£-3.93bn	£-3.99bn	£-4.05bn	£-4.11bn	£-4.24bn	£-1.95bn
Raise child benefit by 25GBP/week per additional child	£-1.99bn	£-1.75bn	£-1.55bn	£-1.38bn	£-1.30bn	£-1.18bn	£-1.07bn
Reduce Universal Credit taper rate to 20%	£-20.77bn	£-21.32bn	£-21.75bn	£-22.00bn	£-22.35bn	£-22.75bn	£-22.94bn
Raise Class 1 main employee NICs rate to 10%	£10.89bn	£11.30bn	£11.71bn	£12.01bn	£12.31bn	£12.62bn	£13.00bn
Raise VAT standard rate by 2pp	£24.89bn	£25.71bn	£26.63bn	£27.24bn	£27.87bn	£28.50bn	£29.14bn
Raise additional rate by 3pp	£2.90bn	£3.15bn	£3.22bn	£3.41bn	£3.61bn	£3.85bn	£4.14bn
Raise the Universal Credit standard allowance by 10%	£-3.06bn	£-3.22bn	£-3.30bn	£-3.39bn	£-3.48bn	£-3.53bn	£-3.54bn
Raise the State Pension by 10%	£-7.76bn	£-7.99bn	£-8.22bn	£-8.44bn	£-8.79bn	£-8.52bn	£-8.86bn

Standard reforms: change in each reform's target: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Raise basic rate by 1pp: change in income_tax	£6.55bn	£6.86bn	£6.79bn	£7.00bn	£7.20bn	£7.44bn	£7.66bn
Raise higher rate by 1pp: change in income_tax	£3.61bn	£3.92bn	£4.01bn	£4.23bn	£4.45bn	£4.72bn	£4.84bn
Raise personal allowance by ~800GBP/year: change in income_tax	£-3.93bn	£-4.07bn	£-4.13bn	£-4.18bn	£-4.22bn	£-4.40bn	£-1.75bn
Raise child benefit by 25GBP/week per additional child: change in child_benefit	£2.33bn	£2.14bn	£1.94bn	£1.76bn	£1.65bn	£1.52bn	£1.40bn
Reduce Universal Credit taper rate to 20%: change in universal_credit	£20.74bn	£21.31bn	£21.79bn	£22.05bn	£22.37bn	£22.78bn	£22.99bn
Raise Class 1 main employee NICs rate to 10%: change in national_insurance	£11.15bn	£11.63bn	£12.00bn	£12.29bn	£12.61bn	£12.94bn	£13.31bn
Raise VAT standard rate by 2pp: change in vat	£24.69bn	£25.51bn	£26.42bn	£27.03bn	£27.65bn	£28.28bn	£28.91bn
Raise additional rate by 3pp: change in income_tax	£2.90bn	£3.15bn	£3.22bn	£3.42bn	£3.62bn	£3.86bn	£4.12bn
Raise the Universal Credit standard allowance by 10%: change in universal_credit	£3.06bn	£3.22bn	£3.32bn	£3.41bn	£3.47bn	£3.53bn	£3.55bn
Raise the State Pension by 10%: change in state_pension	£10.68bn	£11.17bn	£11.28bn	£11.60bn	£12.03bn	£12.46bn	£12.96bn