[juaristi22]

Fixes #2660.

Add seven property tests for the Housing Benefit family premium, four full-person pension-age fixtures covering Great Britain and Northern Ireland in both person orders, and a 2015 case with all five applicable-amount components positive. Document the eligibility assumptions and the primary sources for the fixed expectations.

The properties cover family size, missing included children, closure dates, protected categories, historical lone-parent routing, supported amounts and an independently reformable Northern Ireland closure date. Tests extending through 2030 check parameter and projection contracts; they do not assert future legislation or published rates.

Claim-continuity categories and the adult carer-premium entitlement are supplied premises. The tests exercise the family-premium and applicable-amount component contracts; the documentation explains these limits. The fixed component totals exclude child personal allowance, which is not modelled (#2232); the £3,123.12 component is the disabled-child premium.

Validation: 47 test items passed across three focused executions: seven property tests, 20 family-premium YAML cases and 20 applicable-amount YAML cases. The property tests reported 84 generated passing cases within those seven tests; explicit examples remain separate. Ruff format and lint passed. The local test execution used the five final working-file versions over base 49a75906; committing unchanged files does not constitute a second execution.

The review follow-up changes documentation and YAML comments only. Static checks confirm all 40 parsed YAML cases, the property module and the production variables and parameters remain unchanged. No model tests ran for this clarification.

Independent incremental canonical review: COMPLETE / APPROVE at commit 989b4a106ab8f0d986fef2488e209411c9f3dc6d, with zero findings and zero material gaps. The prior review and test executions retain their original commit and working-file labels.

axiom: n/a: Test coverage and documentation; policy formulas and parameters are unchanged.

[github-actions]

Aggregate impact on certified data: pass

Base fba0c0a53e against head 53a3740b18, 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

Standard reform costings (change in gov_balance)

Measure	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Raise additional rate by 3pp	0	0	0	0	0	suppressed	suppressed

Standard reforms: change in each reform's target

Measure	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Raise additional rate by 3pp: change in income_tax	0	0	0	0	0	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.

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 £-53,889,156 in total; 2026-27: 76 units below zero, a weighted £-55,420,387 in total; 2027-28: 76 units below zero, a weighted £-56,618,038 in total

Counted-once check

Each of 91 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 fba0c0a53e	uk 2.162.3 (files 094c8502b994), core 3.33.2, py 3.13.17 aarch64	6e6b7066671c	4f86ac4248d9	1853.26s
head	#2677 merged into main 53a3740b18	uk 2.162.3 (files 094c8502b994), core 3.33.2, py 3.13.17 aarch64	6e6b7066671c	4f86ac4248d9	1843.86s

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	£298.70bn	£318.31bn	£335.60bn	£350.52bn	£365.79bn	£383.53bn	£401.03bn
National Insurance (employee and self-employed)	£52.37bn	£54.71bn	£56.48bn	£58.15bn	£60.22bn	£62.11bn	£64.44bn
National Insurance (employer)	£150.59bn	£156.99bn	£161.74bn	£166.13bn	£173.24bn	£178.59bn	£185.29bn
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	£12.61bn	£13.05bn	£13.53bn	£14.02bn	£14.52bn	£15.05bn	£15.58bn
Student loan repayments	£7.91bn	£8.21bn	£8.43bn	£8.63bn	£8.85bn	£9.10bn	£9.42bn
VAT excluding private school fees	£249.37bn	£255.28bn	£261.81bn	£267.87bn	£274.12bn	£280.56bn	£286.81bn
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	£2.00bn	£2.05bn	£2.10bn	£2.21bn	£2.21bn	£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	£24.53bn	£24.64bn	£26.64bn	£26.69bn	£26.42bn	£25.76bn	£26.35bn
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	£4.41bn	£4.42bn	£4.44bn	£4.45bn	£4.47bn	£4.48bn
Council tax	£49.21bn	£51.88bn	£54.97bn	£58.29bn	£61.55bn	£64.92bn	£68.49bn
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	£38.04bn	£38.88bn	£39.76bn	£43.07bn	£43.13bn	£44.57bn
Stamp duty land tax on the household's own purchases	£6.90bn	£7.39bn	£7.81bn	£8.21bn	£8.62bn	£9.02bn	£9.42bn
Stamp duty land tax paid by companies	£4.81bn	£5.98bn	£6.73bn	£7.46bn	£8.21bn	£8.87bn	£9.16bn
Land transaction tax (Wales)	£0.07bn	£0.08bn	£0.09bn	£0.09bn	£0.10bn	£0.10bn	£0.11bn
Land and buildings transaction tax (Scotland)	£0.31bn	£0.32bn	£0.34bn	£0.35bn	£0.37bn	£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	£121.64bn	£126.07bn	£127.08bn	£128.87bn	£132.52bn	£136.31bn	£140.08bn
Pension Credit	£6.66bn	£7.04bn	£7.32bn	£7.46bn	£7.60bn	£7.77bn	£7.94bn
Winter Fuel Payment	£1.86bn	£1.86bn	£1.80bn	£1.78bn	£1.79bn	£1.79bn	£1.80bn
Pension Age Winter Heating Payment (Scotland)	£0.19bn	£0.20bn	£0.20bn	£0.21bn	£0.21bn	£0.22bn	£0.22bn
Universal Credit	£75.21bn	£80.38bn	£82.93bn	£84.23bn	£85.58bn	£86.87bn	£87.97bn
Housing Benefit	£8.55bn	£8.89bn	£9.17bn	£9.31bn	£9.58bn	£9.84bn	£10.10bn
Council Tax Reduction	£1.98bn	£2.02bn	£2.07bn	£2.11bn	£2.16bn	£2.21bn	£2.25bn
Employment and Support Allowance (income-related)	£0.79bn	£0.81bn	£0.83bn	£0.85bn	£0.86bn	£0.89bn	£0.90bn
Employment and Support Allowance (contribution-based)	£5.20bn	£5.34bn	£5.46bn	£5.59bn	£5.72bn	£5.85bn	£5.99bn
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	£0.30bn	£0.31bn	£0.32bn	£0.32bn	£0.33bn
Income Support	£0.12bn	£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	£26.94bn	£28.06bn	£29.13bn	£29.83bn	£30.54bn	£31.26bn	£31.96bn
Disability Living Allowance	£7.49bn	£7.80bn	£8.10bn	£8.29bn	£8.49bn	£8.69bn	£8.88bn
Attendance Allowance	£8.68bn	£9.04bn	£9.38bn	£9.61bn	£9.83bn	£10.07bn	£10.29bn
Carer's Allowance	£4.48bn	£4.67bn	£4.84bn	£4.96bn	£5.08bn	£5.19bn	£5.31bn
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	£0.04bn	£0.04bn	£0.04bn	£0.04bn
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	£0.53bn	£0.54bn	£0.55bn	£0.57bn	£0.58bn
Armed Forces Compensation Scheme	£0.61bn	£0.62bn	£0.64bn	£0.65bn	£0.67bn	£0.68bn	£0.70bn
War Widow's or Widower's Pension	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Child Benefit	£16.16bn	£16.83bn	£17.43bn	£17.85bn	£18.26bn	£18.69bn	£19.10bn
Scottish Child Payment	£0.49bn	£0.52bn	£0.54bn	£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	£3.39bn	£3.47bn	£3.55bn	£3.63bn	£3.72bn	£3.80bn
Statutory Paternity Pay	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Statutory Sick Pay	£1.12bn	£1.15bn	£1.18bn	£1.21bn	£1.24bn	£1.27bn	£1.29bn
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	£0.70bn	£0.72bn	£0.73bn	£0.75bn	£0.77bn
Widowed Parent's Allowance	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn	£0.00bn
Tax-Free Childcare	£0.55bn	£0.56bn	£0.57bn	£0.58bn	£0.59bn	£0.61bn	£0.59bn
Extended childcare entitlement	£2.99bn	£3.50bn	£3.60bn	£3.67bn	£3.77bn	£3.85bn	£3.94bn
Universal childcare entitlement	£2.05bn	£2.23bn	£2.28bn	£2.34bn	£2.40bn	£2.47bn	£2.52bn
Targeted childcare entitlement	£0.50bn	£0.51bn	£0.52bn	£0.53bn	£0.54bn	£0.56bn	£0.52bn
Childcare Offer for Wales	£0.26bn	£0.28bn	£0.28bn	£0.29bn	£0.30bn	£0.30bn	£0.31bn
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	£203.83bn	£204.54bn	£205.13bn	£205.79bn	£206.49bn	£207.23bn	£207.73bn
State education spending	£0.02bn	£0.02bn	£0.02bn	£0.02bn	£0.02bn	£0.02bn	£0.02bn
Transport subsidy spending	£25.05bn	£25.13bn	£25.21bn	£25.29bn	£25.37bn	£25.46bn	£25.53bn
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
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	11,261k	11,158k	10,849k	10,746k	10,783k	10,822k	10,848k
Pension Credit	1,485k	1,483k	1,480k	1,461k	1,462k	1,464k	1,460k
Winter Fuel Payment	7,842k	7,793k	7,494k	7,407k	7,432k	7,459k	7,477k
Pension Age Winter Heating Payment (Scotland)	803k	803k	803k	800k	803k	806k	808k
Universal Credit	6,334k	6,341k	6,366k	6,347k	6,345k	6,333k	6,298k
Housing Benefit	1,249k	1,247k	1,250k	1,234k	1,238k	1,240k	1,239k
Council Tax Reduction	3,175k	3,198k	3,209k	3,229k	3,244k	3,257k	3,264k
Employment and Support Allowance (income-related)	71k	71k	71k	71k	71k	72k	72k
Employment and Support Allowance (contribution-based)	719k	721k	723k	726k	728k	731k	732k
Jobseeker's Allowance (income-based)	0k	0k	0k	0k	0k	0k	0k
Jobseeker's Allowance (contribution-based)	67k	67k	67k	68k	68k	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	3,566k	3,579k	3,589k	3,601k	3,613k	3,626k	3,635k
Disability Living Allowance	1,291k	1,295k	1,299k	1,303k	1,308k	1,312k	1,316k
Attendance Allowance	1,694k	1,700k	1,705k	1,711k	1,716k	1,723k	1,727k
Carer's Allowance	1,034k	1,038k	1,041k	1,044k	1,048k	1,051k	1,053k
Carer Support Payment (Scotland)	71k	71k	72k	72k	72k	72k	73k
Carer's Allowance Supplement (Scotland)	0k	71k	72k	72k	72k	72k	73k
Severe Disablement Allowance	4k	4k	4k	4k	4k	4k	4k
Industrial Injuries Disablement Benefit	137k	137k	138k	138k	139k	139k	140k
Armed Forces Compensation Scheme	93k	93k	94k	94k	94k	95k	95k
War Widow's or Widower's Pension	0k	0k	0k	0k	0k	0k	0k
Child Benefit	8,102k	8,128k	8,142k	8,165k	8,191k	8,216k	8,232k
Scottish Child Payment	350k	352k	353k	357k	354k	355k	342k
Two Child Limit Payment (Scotland, counterfactual)	0k	0k	0k	0k	0k	0k	0k
Healthy Start vouchers	199k	200k	201k	201k	202k	203k	203k
Maternity Allowance	0k	0k	0k	0k	0k	0k	0k
Statutory Maternity Pay	332k	334k	335k	336k	337k	338k	339k
Statutory Paternity Pay	0k	0k	0k	0k	0k	0k	0k
Statutory Sick Pay	181k	182k	182k	183k	183k	184k	185k
Sure Start Maternity Grant	26k	26k	26k	26k	26k	27k	27k
Bereavement Support Payment	98k	98k	98k	99k	99k	99k	100k
Widowed Parent's Allowance	0k	0k	0k	0k	0k	0k	0k
Tax-Free Childcare	1,014k	1,024k	1,024k	1,027k	1,027k	1,031k	1,013k
Extended childcare entitlement	796k	801k	806k	809k	815k	819k	820k
Universal childcare entitlement	1,071k	1,074k	1,077k	1,080k	1,086k	1,096k	1,097k
Targeted childcare entitlement	165k	156k	154k	155k	155k	156k	144k
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	99k	99k	99k	100k	100k
Adult Dependants' Grant	18k	18k	12k	12k	12k	13k	13k
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
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	£898.82bn	£941.86bn	£980.11bn	£1,013.84bn	£1,052.89bn	£1,089.01bn	£1,129.10bn
Government spending	£528.87bn †	£543.67bn †	£551.43bn †	£557.71bn †	£566.13bn †	£574.77bn †	£582.74bn †
Government balance, each receipt once	£369.95bn †	£398.19bn †	£428.68bn †	£456.13bn †	£486.76bn †	£514.23bn †	£546.36bn †
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	£898.82bn	£941.86bn	£980.11bn	£1,013.84bn	£1,052.89bn	£1,089.01bn	£1,129.10bn
household_tax	£496.91bn	£527.60bn	£554.51bn	£577.74bn	£603.32bn	£627.65bn	£654.69bn
pre_budget_change_household_tax	£489.00bn	£519.39bn	£546.08bn	£568.63bn	£593.98bn	£618.05bn	£644.75bn
gov_spending	£528.87bn †	£543.67bn †	£551.43bn †	£557.71bn †	£566.13bn †	£574.77bn †	£582.74bn †
household_benefits	£528.87bn †	£543.67bn †	£551.43bn †	£557.71bn †	£566.13bn †	£574.77bn †	£582.74bn †
gov_balance	£369.95bn †	£398.19bn †	£428.68bn †	£456.13bn †	£486.76bn †	£514.23bn †	£546.36bn †

Household income totals: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Household market income	£1,651.49bn	£1,713.03bn	£1,764.05bn	£1,812.97bn	£1,862.19bn	£1,918.39bn	£1,985.28bn
Household net income	£1,644.34bn †	£1,688.53bn †	£1,719.29bn †	£1,750.26bn †	£1,781.23bn †	£1,820.53bn †	£1,866.75bn †
Household net income (HBAI definition)	£1,457.21bn	£1,504.32bn	£1,537.33bn	£1,569.01bn	£1,602.22bn	£1,639.95bn	£1,686.40bn

Population: head levels

Measure (head)	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
People	69,224k	69,466k	69,668k	69,891k	70,128k	70,381k	70,550k
Benefit units	35,100k	35,223k	35,325k	35,438k	35,558k	35,686k	35,772k
Households	31,037k	31,145k	31,236k	31,336k	31,442k	31,555k	31,631k

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	16.0%	15.1%	15.5%	15.6%	15.7%	15.8%	15.8%
Absolute poverty, before housing costs: children	24.0%	21.2%	21.5%	21.5%	21.7%	21.9%	21.8%
Absolute poverty, before housing costs: working-age adults	13.8%	13.5%	14.0%	14.1%	14.2%	14.2%	14.3%
Absolute poverty, before housing costs: pensioners	13.7%	13.2%	13.1%	13.4%	13.5%	13.5%	13.5%
Absolute poverty, after housing costs: everyone	21.5%	20.8%	21.3%	21.5%	21.8%	21.9%	22.2%
Absolute poverty, after housing costs: children	33.1%	30.7%	31.1%	31.1%	31.4%	31.7%	32.3%
Absolute poverty, after housing costs: working-age adults	19.8%	19.6%	20.3%	20.5%	20.7%	20.9%	21.1%
Absolute poverty, after housing costs: pensioners	12.7%	12.4%	12.3%	12.5%	12.9%	12.9%	13.0%
Relative poverty, before housing costs: everyone	17.2%	16.4%	16.5%	16.4%	16.3%	16.4%	16.6%
Relative poverty, before housing costs: children	26.2%	23.5%	23.4%	23.1%	22.8%	23.0%	23.3%
Relative poverty, before housing costs: working-age adults	14.6%	14.4%	14.7%	14.7%	14.6%	14.7%	14.9%
Relative poverty, before housing costs: pensioners	15.0%	14.8%	14.1%	14.1%	14.0%	14.0%	14.2%
Relative poverty, after housing costs: everyone	21.6%	21.0%	21.2%	21.2%	21.3%	21.4%	21.8%
Relative poverty, after housing costs: children	33.3%	31.2%	30.9%	30.7%	31.0%	31.0%	31.5%
Relative poverty, after housing costs: working-age adults	19.9%	19.8%	20.1%	20.3%	20.5%	20.5%	20.8%
Relative poverty, after housing costs: pensioners	12.9%	12.4%	12.1%	11.9%	11.8%	11.9%	12.8%

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	11,051k	10,489k	10,774k	10,897k	11,005k	11,092k	11,140k
Absolute poverty, before housing costs: children	3,580k	3,185k	3,232k	3,242k	3,284k	3,321k	3,324k
Absolute poverty, before housing costs: working-age adults	5,846k	5,754k	6,039k	6,139k	6,191k	6,232k	6,270k
Absolute poverty, before housing costs: pensioners	1,625k	1,550k	1,504k	1,517k	1,530k	1,539k	1,545k
Absolute poverty, after housing costs: everyone	14,858k	14,424k	14,825k	15,016k	15,271k	15,438k	15,663k
Absolute poverty, after housing costs: children	4,944k	4,610k	4,671k	4,688k	4,757k	4,821k	4,919k
Absolute poverty, after housing costs: working-age adults	8,410k	8,361k	8,749k	8,916k	9,053k	9,141k	9,257k
Absolute poverty, after housing costs: pensioners	1,504k	1,454k	1,405k	1,412k	1,461k	1,475k	1,487k
Relative poverty, before housing costs: everyone	11,898k	11,405k	11,470k	11,490k	11,425k	11,528k	11,710k
Relative poverty, before housing costs: children	3,918k	3,524k	3,519k	3,491k	3,451k	3,492k	3,550k
Relative poverty, before housing costs: working-age adults	6,203k	6,137k	6,339k	6,402k	6,387k	6,441k	6,540k
Relative poverty, before housing costs: pensioners	1,776k	1,744k	1,611k	1,597k	1,587k	1,595k	1,621k
Relative poverty, after housing costs: everyone	14,969k	14,592k	14,740k	14,824k	14,961k	15,048k	15,363k
Relative poverty, after housing costs: children	4,977k	4,676k	4,652k	4,634k	4,691k	4,712k	4,794k
Relative poverty, after housing costs: working-age adults	8,455k	8,452k	8,697k	8,846k	8,924k	8,983k	9,107k
Relative poverty, after housing costs: pensioners	1,537k	1,464k	1,391k	1,344k	1,346k	1,354k	1,462k

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	0.3086	0.3059	0.3066	0.3072	0.3077	0.3083	0.3096

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	£17,773 †	£17,876 †	£17,831 †	£17,889 †	£18,127 †	£18,315 †	£18,445 †
Decile 2: mean household_net_income per household	£27,956 †	£28,855 †	£28,514 †	£28,878 †	£29,157 †	£29,624 †	£30,132 †
Decile 3: mean household_net_income per household	£34,379 †	£35,481 †	£36,103 †	£36,490 †	£36,752 †	£37,303 †	£38,128 †
Decile 4: mean household_net_income per household	£38,782 †	£40,746 †	£41,895 †	£42,415 †	£43,112 †	£43,928 †	£44,188 †
Decile 5: mean household_net_income per household	£43,785 †	£44,532 †	£45,603 †	£46,280 †	£47,374 †	£48,286 †	£49,557 †
Decile 6: mean household_net_income per household	£48,210 †	£49,520 †	£50,751 †	£51,516 †	£52,206 †	£53,079 †	£54,258 †
Decile 7: mean household_net_income per household	£56,210 †	£57,193 †	£57,748 †	£58,266 †	£58,991 †	£60,089 †	£61,812 †
Decile 8: mean household_net_income per household	£69,153 †	£70,584 †	£71,803 †	£73,070 †	£74,090 †	£75,614 †	£77,419 †
Decile 9: mean household_net_income per household	£79,488 †	£81,416 †	£82,836 †	£84,144 †	£85,527 †	£87,051 †	£89,927 †
Decile 10: mean household_net_income per household	£117,580 †	£120,294 †	£121,931 †	£124,160 †	£126,041 †	£128,335 †	£131,104 †

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	£6.47bn	£6.76bn	£6.67bn	£6.86bn	£7.06bn	£7.35bn	£7.55bn
Raise higher rate by 1pp	£3.69bn	£3.98bn	£4.03bn	£4.29bn	£4.46bn	£4.78bn	£4.91bn
Raise personal allowance by ~800GBP/year	£-3.82bn	£-3.94bn	£-4.01bn	£-4.09bn	£-4.18bn	£-4.18bn	£-2.00bn
Raise child benefit by 25GBP/week per additional child	£-1.99bn	£-1.75bn	£-1.56bn	£-1.46bn	£-1.35bn	£-1.24bn	£-1.12bn
Reduce Universal Credit taper rate to 20%	£-20.39bn	£-20.96bn	£-21.38bn	£-21.57bn	£-21.87bn	£-22.17bn	£-22.60bn
Raise Class 1 main employee NICs rate to 10%	£11.02bn	£11.42bn	£11.77bn	£12.07bn	£12.37bn	£12.75bn	£13.07bn
Raise VAT standard rate by 2pp	£24.89bn	£25.55bn	£26.14bn	£26.75bn	£27.39bn	£28.03bn	£28.66bn
Raise additional rate by 3pp	£2.96bn	£3.21bn	£3.26bn	£3.46bn	£3.65bn	suppressed	suppressed
Raise the Universal Credit standard allowance by 10%	£-3.02bn	£-3.15bn	£-3.26bn	£-3.30bn	£-3.34bn	£-3.39bn	£-3.44bn
Raise the State Pension by 10%	£-7.79bn	£-8.02bn	£-8.01bn	£-8.12bn	£-8.43bn	£-8.54bn	£-8.87bn

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	£6.61bn	£6.91bn	£6.83bn	£7.03bn	£7.24bn	£7.47bn	£7.73bn
Raise higher rate by 1pp: change in income_tax	£3.69bn	£3.99bn	£4.04bn	£4.25bn	£4.47bn	£4.74bn	£4.93bn
Raise personal allowance by ~800GBP/year: change in income_tax	£-3.95bn	£-4.08bn	£-4.17bn	£-4.24bn	£-4.34bn	£-4.41bn	£-1.76bn
Raise child benefit by 25GBP/week per additional child: change in child_benefit	£2.33bn	£2.14bn	£1.95bn	£1.84bn	£1.73bn	£1.62bn	£1.50bn
Reduce Universal Credit taper rate to 20%: change in universal_credit	£20.39bn	£20.95bn	£21.37bn	£21.62bn	£21.87bn	£22.22bn	£22.61bn
Raise Class 1 main employee NICs rate to 10%: change in national_insurance	£11.28bn	£11.74bn	£12.06bn	£12.37bn	£12.69bn	£13.03bn	£13.49bn
Raise VAT standard rate by 2pp: change in vat	£24.69bn	£25.35bn	£25.94bn	£26.54bn	£27.17bn	£27.81bn	£28.43bn
Raise additional rate by 3pp: change in income_tax	£2.96bn	£3.21bn	£3.26bn	£3.46bn	£3.66bn	suppressed	suppressed
Raise the Universal Credit standard allowance by 10%: change in universal_credit	£3.02bn	£3.15bn	£3.26bn	£3.32bn	£3.39bn	£3.44bn	£3.48bn
Raise the State Pension by 10%: change in state_pension	£10.68bn	£11.18bn	£11.31bn	£11.55bn	£12.00bn	£12.44bn	£12.94bn

[vahid-ahmadi]

Round 1 at 7e3e89bf3.

Verdict: the closure dates, protection rules and rates all match the law, and the tests pass. One should: the fixed applicable-amount totals leave out the child personal allowance without saying so.

What checks out:

• GB closure 20160501 (parameters/gov/dwp/housing_benefit/premiums/family/new_claim_end.yaml) matches SI 2015/1857 reg 1(b). The abolition covers both the working-age and the pension-age regulations (reg 2(1) and 2(2)).
• NI closure 20160905 matches SR 2016/310 reg 1(1). The reg 5(1) carve-out is only the old CTC additional amount (reg 20(1)(d)), so NI pension-age awards are protected too, as the NI fixtures assume.
• Protection ends when the family stops including a child or the person makes a new claim (SI 2015/1857 reg 4(2); SR 2016/310 reg 5(2)). test_no_included_child_has_no_family_premium is consistent with that.
• Rates: £17.45 and £22.20 (SI 2015/457 art 17(8)); £60.06 disabled child and £34.60 carer (SI 2015/457 Sch 6); £256.00 pension-age personal allowance before the April 2021 cutoff, £20.22 family and £22.20 lone-parent rate (DWP 2026-27 rates; SI 2006/214 Sch 3 para 3 as amended by SI 2026/148 art 24(7)).

Findings:

1. should: the totals are labelled as the applicable amount but leave out the child personal allowance. housing_benefit_applicable_amount.yaml:369 pins £9,630.92 and housing_benefit_family_premium.yaml:265, :304, :343, :382 pin £14,363.44. The doc table calls the first "Applicable amount" (docs/engineering/housing-benefit-family-premium-tests.md:45) and line 32 calls the second "the fixed component oracle". Under the PR's own references the applicable amount also includes the child allowance: £66.90 in 2015 (SI 2006/213 Sch 3 para 2, as set by SI 2015/457 Sch 5) and £87.88 in 2026-27 (SI 2006/214 Sch 3 para 2). So the legal totals would be £13,109.72 and £18,933.20. The model leaves this allowance out on purpose (Document deferred historical Housing Benefit child-allowance rules #2232, closed as deferred), so I am not asking you to implement it. Please add one sentence to the doc and the YAML comments, for example "excludes the child personal allowance, not modelled (Document deferred historical Housing Benefit child-allowance rules #2232)". Otherwise, when Document deferred historical Housing Benefit child-allowance rules #2232 is picked up, these fixtures will fail and look like a regression. Also, child3123.12 in the comment at housing_benefit_applicable_amount.yaml:367 is the disabled child premium. Calling it disabled child would stop it reading like the child allowance.
2. nit: test_family_premium_is_within_its_three_supported_amounts (test_housing_benefit_family_premium_properties.py:296-316) only checks that the value is one of {0, ordinary, historical}. The exact-value tests above it already pin each case, so it adds little. The seven property tests took 155 s locally, so dropping it would save some time.
3. nit: the annual convention means NI units in category NONE get nothing in 2016, although NI new claims before 5 September 2016 still got the premium. This is existing model behaviour and the doc says so. I am only noting it.
4. nit: for the 2026 amounts, SI 2026/148 art 24 is a better primary source than the DWP rates page (amount.yaml, 2025 and 2026 entries). This file is outside the PR's diff, so it can wait.

What I ran, at 7e3e89bf3 in a fresh worktree and venv:

• pytest policyengine_uk/tests/test_housing_benefit_family_premium_properties.py: 7 passed in 155 s.
• policyengine-core test on housing_benefit_family_premium.yaml and housing_benefit_applicable_amount.yaml: 40 passed.
• CI was all green at this head. The aggregate-impact report shows no change, as a tests-only PR should.

What I did not check: the NI pension-age allowance and child amounts in SR 2006/406 against the NI instruments (only against the model parameters), and the 2015 lone-parent personal allowances (£57.90 and £73.10), which I took from the model parameters.

🤖 Generated with Claude Code

[juaristi22]

Addressed in 989b4a1. The note now labels both totals as model component totals and explicitly excludes the unmodelled child personal allowance (#2232). All five YAML expectations carry the same qualifier, and the £3,123.12 component is labelled “disabled child.” Inputs, expected values, property tests and production code are unchanged. The optional property cleanup and rate-source citation remain follow-ups.

[vahid-ahmadi]

Round 2 at 989b4a106.

Verdict: the one should is fixed and nothing else changed. No open must or should, so I am approving.

Status of round 1 findings:

1. should, fixed. The doc now calls both totals a "model component total" and says they exclude the child personal allowance, which is not modelled (Document deferred historical Housing Benefit child-allowance rules #2232) (docs/engineering/housing-benefit-family-premium-tests.md:32-34 and :47-50). All five fixed expectations carry the same comment (housing_benefit_family_premium.yaml:265, :305, :345, :385; housing_benefit_applicable_amount.yaml:369), and the £3,123.12 term now reads "disabled child" (:367). The PR body and changelog say the same.
2. nit, left as a follow-up. Fine.
3. nit, noted only. No action needed.
4. nit, left as a follow-up. Fine.

The diff since 7e3e89bf3 is comments, the doc and the changelog only. Inputs, expected values, the property tests and production code are unchanged.

New findings: none.

What I ran, at 989b4a106 in a fresh worktree and venv:

• policyengine-core test on housing_benefit_family_premium.yaml and housing_benefit_applicable_amount.yaml: 40 passed.
• pytest policyengine_uk/tests/test_housing_benefit_family_premium_properties.py: 7 passed in 161 s.
• CI: all 19 checks green at this head, and GitHub reports it mergeable with main.

🤖 Generated with Claude Code

[vahid-ahmadi]

Approving at 989b4a1; see the comment above.