[MaxGhenis]

Stacked on #2017 (in-unit-non-dep-deductions), which is stacked on #2007 (hb-ctr-non-dep-exemptions), for issue #2014. #2017 charges non-dependants inside the claimant's own benefit unit in UC, HB and the national CTR schemes, and kept the five English working-age local schemes on their old aggregation behind a mask. This PR brings those schemes (Merton, Kingston upon Thames, Newham, Westminster, Oxford) into line with the law and with #2017's national variable. It also narrows who the shared eligibility variable excludes personally, which touches the national schemes too.

Status (UK hub build sprint-2077b, 22 Oct)

• Head cf0475ddb. Fast-forward of 663a5b733, same author, no force-push.
• Merges. Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017 at 3efa8bd60 (which carries Apply Housing Benefit and national Council Tax Reduction non-dependant deductions as legislated #2007 at 4a0935b73 and main at 76cfc9e79) as cdac9e416, with four conflicts resolved. Then main at 9d81a5dfa8bd679f2ade4acbcd215a69f03b3cc4 as f526307d8, which merged cleanly.
• Landing order. Apply Housing Benefit and national Council Tax Reduction non-dependant deductions as legislated #2007, then Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017, then this. CI (Test, Lint, Fix evidence, Aggregate impact) runs only on pull requests into main, so none runs here until the base is main. The impact below comes from two workflow_dispatch runs of the Aggregate impact workflow.

The law

Each council's 2026-27 scheme reproduces the Default Scheme's (SI 2012/2886) definitions:

• Merton, Kingston upon Thames and Newham: paras 4, 6 and 9 and the working-age deduction paragraph (30, 30A, 30B).
• Westminster's summary says "The Council Tax Reduction Schemes (Default Scheme) Regulations 2012 form the basis of Westminster's local working age reduction scheme", and its Appendix A gives the 2026-27 scale. It publishes nothing else on non-dependants.
• Oxford: paras 42-47 and the Annex 1 glossary.

What follows from the texts:

• Who is a non-dependant (para 9). Anyone who normally resides with the applicant, except a member of the applicant's family (para 6), a person jointly and severally liable with the applicant (9(2)(d)), a person liable to pay the applicant on a commercial basis (9(2)(e)) and a charity-engaged carer. Para 9(3)(a) brings back as a non-dependant someone who pays "a close relative of his or his partner", or pays under an agreement "other than on a commercial basis". So an adult in the applicant's own benefit unit who is not the partner, a child or a qualifying young person is a non-dependant, and so is each adult in another family.
• Banding (para 30(1)-(2), para 10). A non-dependant in remunerative work, on their own hours, is banded on their normal gross weekly income. For a couple the income is joint (para 30(4); Oxford para 44).
• Couples (para 30(3)). "Only one deduction is to be made ... in respect of a couple ... (other than where there is an award of universal credit)", the higher. Merton and Kingston upon Thames reproduce the exception. Newham's 30B(3) and Oxford's para 44 have none. Westminster follows the Default Scheme, so it keeps the exception (see Readings).
• Joint occupiers (para 30(5)). A non-dependant of two or more liable persons is apportioned equally between them.
• Exemptions (para 30(8)). No deduction for a non-dependant "who is on income support, state pension credit, an income-based jobseeker's allowance or an income-related employment and support allowance". Merton's, Kingston upon Thames's and Newham's texts add one "entitled to an award of universal credit where the award is calculated on the basis that the person does not have any earned income", and Westminster's Appendix A has "In receipt of universal credit with no earned income: nil". Oxford applies its exemptions to pensioner applicants only (para 47).

Changes

_legacy.py:

• local_non_dep_deductions now has the shape of Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017's national council_tax_reduction_non_dep_deductions: claims × joint-liability share × (the household's pool, less the claiming family's own amount, plus its own in-unit non-dependants). It uses Apply Housing Benefit and national Council Tax Reduction non-dependant deductions as legislated #2007's deduction_per_family: one deduction per couple, the higher, or each member's where the scheme keeps the UC exception; anyone else separately. The claiming family's own non-dependants are Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017's is_benefit_unit_non_dependant_for_council_tax_reduction, built on the CTR applicant (Means-test the Council Tax Reduction applicant and partner, not the benefit unit's claimant #2078). So a grandmother who applies alone is charged for the couple in her benefit unit. Main's per-applicant exemption guard (Assess each Council Tax Reduction claim under its own family's scheme and exemption #2015) stays. The local mask is gone.
• normal_gross_income_non_dep_deduction:
  • a claimant or partner is banded on the couple's joint gross income, and anyone else on their own;
  • remunerative work uses each person's own hours;
  • the para 30(8)(a) exemptions use main's payee statuses is_on_income_support, is_on_income_based_jsa, is_on_income_related_esa (Count only the claimant's and partner's legacy awards in means tests and passports #2027) and is_on_pension_credit;
  • the UC exemption uses is_on_universal_credit and the person's own earned income (Apply Housing Benefit and national Council Tax Reduction non-dependant deductions as legislated #2007's has_earned_income, UC Regs 2013 reg 52).

council_tax_reduction_individual_non_dep_deduction_eligible (shared with the national schemes) is (other family | in-unit) & ~personally excluded. The personal exclusions are:

• a joint tenant (is_liable_for_household_rent) who is not their benefit unit's claimant or partner;
• anyone outside the household head's family who pays the householder for their own board or lodging (9(2)(e)), even where the rest of their family pays nothing.

A member of the head's own family who pays board is taken to be a close relative (9(3)(a)(i)) and stays a non-dependant. The model has no relationship input, so a close relative in another family who pays is still treated as a commercial lodger. That gap is documented in the variable and is #2559. The raw is_household_head read is gone.

westminster_council_tax_reduction_non_dep_deductions deducts for each member of a non-dependant couple with Universal Credit, as the Default Scheme's para 30(3) does.

Review responses

Sol review r1 (REQUEST_CHANGES at 663a5b7):

1. UC exemption interpretation. Read on each person's own earnings, as Apply Housing Benefit and national Council Tax Reduction non-dependant deductions as legislated #2007 reads the same words for the national schemes and HB (Readings 1). One-earner couple cases pin it in Merton (each member deducted: the worker's £13.30, the partner nil) and Newham (one deduction: the worker's).
2. Payment alone does not exclude. Fixed as above. Regression cases cover the England pensioner, Scottish, Welsh and Merton schemes: a son who pays his mother board stays her non-dependant. A further case covers a lodger's son who pays the householder himself, in Scotland. The relationship gap is Treat a close relative who pays board as a non-dependant (reg 9(3)(a)) once the model has a relationship input #2559.
3. Integrate main. Done: Assess each Council Tax Reduction claim under its own family's scheme and exemption #2015's per-applicant exemption, Count only the claimant's and partner's legacy awards in means tests and passports #2027's payee predicates and Means-test the Council Tax Reduction applicant and partner, not the benefit unit's claimant #2078's applicant identity are all kept (resolutions below). The oracle's household exemption is now per applicant.
4. Westminster UC couple. Westminster's summary names the Default Scheme as its basis and is silent on couples. The Default Scheme's para 30(3) keeps the UC exception, so Westminster now deducts for each member (Readings 2). A YAML case pins it: £15.95 + £5.20 a week.
5. Conservation. The joint-liability share follows the regulations' per-person wording (main's documented reading), so shares need not sum to one: a couple jointly liable with a lone sharer leaves the partner's third unborne, for the liability and the deduction alike. The invariant is restated that way, and property 5 asserts it. In every household with no exempt applicant, the claiming families bear the pool times the sum of their shares, which is the whole pool, each non-dependant once, wherever the shares sum to one.
6. Main-versus-head impact. Two certified-data runs (below).

Maintainer review (vahid-ahmadi, 5 Oct):

1. Rebase: done (merges above).
2. Count only the claimant's and partner's legacy awards in means tests and passports #2027: is_on_* for IS, JSA and ESA, and is_on_pension_credit for State Pension Credit, because para 30(8)(a) uses one "who is on" for all four (Readings 3). Count only the claimant's and partner's legacy awards in means tests and passports #2027's Merton case ("A non-dependant couple on ESA with a working partner pays the partner's deduction on their joint income") is on main and passes here.
3. Grandmother cases: both the pool and eligibility now key on the CTR applicant.
   • Means-test the Council Tax Reduction applicant and partner, not the benefit unit's claimant #2078's three "provisional until Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017" cases in applicant_or_partner.yaml passed only because the 19-year-old parents defaulted to tertiary education. They are now not in education, and the Newham father works 37.5 hours. Newham gives your probe's result: one deduction, the father's £1,175.72, and a reduction of £84.28. The mother has no earned income of her own, so she is exempt. The England pensioner JSA case charges the non-payee £270.40 (reduction £489.20). In Kingston upon Thames both are exempt on UC with no earned income (unchanged £1,627.32).
   • Main's IIDB head-alone case now charges the in-unit couple, as its comment anticipated ("no non-dependant deduction for them (Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017)"): £270.40, so council_tax_benefit is £1,195.968.
4. Eligibility keeps (other_family | in_unit) & ~personally_excluded, with Assess each Council Tax Reduction claim under its own family's scheme and exemption #2015's claimant-family test inside other_family.
5. The changelog now names the national change. The survey household counts are gone from the body.
6. Close relatives who pay board: handled where the data allow, otherwise documented, and the follow-up issue is Treat a close relative who pays board as a non-dependant (reg 9(3)(a)) once the model has a relationship input #2559.

Max's comment (6 Oct, resolved head): no formula here reads is_household_head.

Readings (d1398, parked)

Under Max's 20 Oct delegation (single readings are the session's call, logged in source-conflicts/RULINGS.md; rows handed to the hub to append):

1. UC exemption, own earnings. "The person does not have any earned income" is tested on the person's own earnings. Both joint claimants are entitled to the award. This is Apply Housing Benefit and national Council Tax Reduction non-dependant deductions as legislated #2007's reading for the national schemes and HB, so one meaning holds across schemes. It binds only for a non-dependant UC couple where exactly one member earns.
2. Westminster, the Default Scheme's para 30(3) exception. The scheme's stated basis governs where its own published text is silent. Recheck if Westminster's full scheme text is obtained.
3. "On" State Pension Credit means payable to them, as for the other three benefits in the same limb (Apply Housing Benefit and national Council Tax Reduction non-dependant deductions as legislated #2007 reads PC by payee too).
4. Close-relative presumption for a board-payer in the household head's own benefit unit (data approximation, Treat a close relative who pays board as a non-dependant (reg 9(3)(a)) once the model has a relationship input #2559).

Invariants

For every input:

1. Oracle (property 5). Each council's individual and family deductions equal an independent calculation from its 2026-27 scale and the generated structure. Every other council's variables are zero. Who claims and each claim's share are derived from the structure and asserted against the model. Who is on each award is read from the model.
2. Conservation (property 5). Without an exempt applicant, a household's claiming families bear its pool times the sum of their shares. That is the whole pool, each non-dependant once, wherever the shares sum to one.
3. Independence (property 6). The earnings of an adult who is not a claimant or partner change no one else's deduction.
4. No self-charge. A claiming family is never charged for its own applicant, partner or children (Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017's eligibility property and the oracle's own-family subtraction).
5. National properties 1-4 (Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017) still hold with the narrowed exclusions.

Tests

• YAML, every file that touches CTR or non-dependants (64 files): 874 passed, 0 failed, at the final model code (policyengine-core test, single process). This includes local_scheme_non_dependants.yaml (25 cases, every expectation hand-computed from the scheme text). benefit_unit_non_dependants.yaml gains 5 cases, and the renamed Newham case replaces Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017's mask-pinning one.
• The changes bind. Against a git archive export of the parent (Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017 at 3efa8bd60 merged with main, 7ba613fb9), 21 of this head's cases in the three PR YAML files fail, including all three reproducers. The national close-relative cases pass there too. They guard against the previous head's wholesale lodger exclusion.
• Property tests (-n 4): the four core files, test_benefit_unit_non_dependant_properties.py (including local properties 5-6), test_household_head_agreement_properties.py, test_non_dependant_deduction_properties.py and test_council_tax_reduction_claimant_family_scheme_properties.py: 17 passed. A second batch of eight CTR property files (applicant, claimant, legacy award readers, sharers/boarders/lodgers, young person, Child Benefit, UC non-dependant Pension Credit, prescribed benefits): 45 passed. That makes 62 of 62.
• Lint: uvx ruff@latest (0.17.1, CI's unpinned version): format --check ., check . and check --select F811,F821 policyengine_uk are all clean.

Impact

Two workflow_dispatch runs of the Aggregate impact workflow, on the certified enhanced_frs_2024_25.h5 (policyengine-uk-data 1.58.1, sha256 056e80fd8e91, verified on both sides), fiscal years 2025-26 to 2031-32, at head aaf01f968. The later commits change only tests and a code comment.

1. This PR's own change (run 39732669012). The base is #2017 at 3efa8bd60 merged with main at 9d81a5dfa (7ba613fb9, pushed as wip/sprint-2077b-impact-base for the run):

• no household's net income changes in any year;
• 0 checks broken and no moves flagged; the one check failing on both sides is main's sign:vat.

So on survey data the local-scheme, Westminster and eligibility changes move no aggregate. They change household calculations in the five councils, and for board-payers outside the head's family and joint tenants entered as inputs.

2. The whole stack (#2007 + #2017 + this) against main at 9d81a5dfa (run 39732671972). 0 checks broken. All of this comes from #2007 and #2017; run 1 shows this PR adds nothing.

Measure	2025-26	2026-27	2027-28	2028-29	2029-30	2030-31	2031-32
Universal Credit	+£57.5m	+£59.9m	+£59.0m	+£60.4m	+£61.9m	+£63.4m	+£65.0m
Housing Benefit	+£17.3m	+£18.0m	+£18.5m	+£19.0m	+£19.5m	+£20.0m	+£20.4m
Council Tax Reduction	+£6.3m	+£6.8m	+£7.2m	+£7.7m	+£9.1m	+£9.6m	+£10.2m
Government spending	+£81.1m	+£84.7m	+£84.6m	+£87.1m	+£90.5m	+£93.0m	+£95.7m
Absolute poverty AHC, everyone	-7.2k	-11.7k	-11.5k	-11.6k	-5.3k	-5.4k	-5.5k

The run flags 11 moves: decile means of up to ±£260 (2028-29 to 2031-32), and child relative poverty of +0.16pp (+24.2k AHC in 2029-30 and +23.9k BHC in 2031-32). They come from the base PRs (run 1 flags none). Each relative-poverty flag is a single-year jump between years of small falls. #2007's report explains its own 2027-28 flag by the line comparison.

Axiom

axiom: TheAxiomFoundation/rulespec-uk#426 queued. The Kingston upon Thames, Merton and Newham modules derive each non-dependant's deduction from their own income and hours, which is encoded-correct given its inputs. They take who is a non-dependant, the exemption and the household total as inputs. Westminster defers Appendix A, and Oxford has no module.

Coordination

• Apply Housing Benefit and national Council Tax Reduction non-dependant deductions as legislated #2007, Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017: this PR's base chain; land in that order. Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017's own CI will meet main's IIDB head-alone case. This PR updates it, and Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017 needs the same update if it merges main first.
• Assess each Council Tax Reduction claim under its own family's scheme and exemption #2015, Give Council Tax Reduction to the household head's family, not the oldest adult's #2009, Count only the claimant's and partner's legacy awards in means tests and passports #2027, Means-test the Council Tax Reduction applicant and partner, not the benefit unit's claimant #2078: merged. Their changes are kept as listed above.

Reproducer: policyengine_uk/tests/policy/baseline/gov/local_authorities/council_tax_reduction/local_scheme_non_dependants.yaml::Merton charges the applicant's own non-dependant son for his own earnings
Reproducer: policyengine_uk/tests/policy/baseline/gov/local_authorities/council_tax_reduction/local_scheme_non_dependants.yaml::Westminster deducts for each member of a Universal Credit couple, as the Default Scheme does
Reproducer: policyengine_uk/tests/policy/baseline/finance/benefit/family/benefit_unit_non_dependants.yaml::CTR (Scotland), a lodger's adult son who pays the householder himself is not a non-dependant

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[vahid-ahmadi]

Thanks Max. The rules applied match each scheme:

• Who is a non-dependant: charging in-unit adults follows para 9 ("any person ... who normally resides with an applicant", except "any member of the applicant's family").
• Couples: one deduction, the higher, on joint income follows para 30(3)-(4).
• Joint liability: the apportionment follows para 30(5).
• Merton and Kingston: the per-member UC deduction matches the Default Scheme's own "(other than where there is an award of universal credit)".

Verified at 663a5b7:

• Tests: the local_authorities YAML passes 67/67, benefit_unit_non_dependants 28/28 and properties 6/6.
• Probe for Newham, 2026:
  • The household: a grandmother aged 55 applies alone. A 19-year-old couple live with her as another family; the father earns £30,000 and works 37.5 hours.
  • The deduction is £1,175.72 (£22.61 × 52 on joint income of £576.92 a week). The mother's own deduction, £392.08, is the lower, so it is not taken.
  • CTR is £84.28.

1. Blocking: needs a rebase. #2017 conflicts with main in 6 files, and this PR adds a seventh, _legacy.py (from #2009, merged 4 Oct). This is the same standard as #2015 and #2078. #2030 is also stacked on #2017.
2. Should fix: #2027 is missing from Coordination, and the conflict at _legacy.py:175-179 changes amounts.
   • The case: Merton, a non-dependant couple. One reports £5,000 of income-related ESA; the other works 20 hours on £15,000.
   • Here: no deduction, CTR £1,800.
   • With #2027's is_on_*: £551.20 deducted, CTR £1,248.80.
   • Default Scheme para 2(4) ("payable to him") with para 30(3) supports #2027.
   • Take #2027's is_on_* there, keep your claimant-or-partner gate on the Pension Credit (:179) and UC limbs, and add the case.
3. Should fix: this does not fix the #2078 grandmother cases.
   • Both own_family_member (_legacy.py:114) and in_unit (council_tax_reduction_individual_non_dep_deduction_eligible.py:40) key on is_claimant_or_partner.
   • So when the head applies alone and the inference makes the 19-year-olds the unit's couple, they count as neither her family nor her non-dependants.
   • Put my probe household in one benefit unit and this PR gives a £0 deduction. Under paras 6 and 9 it should be £1,175.72, giving CTR of £84.28.
   • Whichever PR lands second should key both on is_council_tax_reduction_applicant_or_partner from #2015/#2078.
   • #2078's Newham and Kingston grandmother cases also need explicit inputs:
     • set the young father's weekly_hours, so the hours band applies;
     • set current_education for the 19-year-olds, who otherwise default to tertiary education and fall under the full-time student exemption (para 30(7)(c)).
     • Without these, those cases give a £0 deduction whatever the non-dependant logic does.
4. Should fix: the agreed #2015 resolution covers _legacy.py but not the eligibility file.
   • #2015 rewrites that test as ~claimant_benunit & ~benunit_is_rent_liable, which drops in_unit.
   • Keep (other_family | in_unit) & ~personally_excluded, and put #2015's claimant-benefit-unit test inside other_family.
5. Should fix: the review-1 fix changes council_tax_reduction_individual_non_dep_deduction_eligible, which the national schemes share. That is the body's −£3.4bn on the intermediate.
   • Say so in the title and changelog: changelog.d/2014-local.fixed.md mentions only the local schemes.
   • Also remove the survey household counts ("135 survey households", "134", "54").
6. Nit: close relatives who pay board are non-dependants.
   • Para 9(3)(a)(i) makes someone who pays a close relative a non-dependant again: "that person is a close relative of his or his partner".
   • council_tax_reduction_individual_non_dep_deduction_eligible.py:47-51 excludes every boarder and lodger, for example an adult son paying his mother board. Main does the same through in_other_non_liable_family.
   • There is no relationship input, so document the gap in the variable and open a follow-up issue.

[MaxGhenis]

#2062 is now on main (merge commit c4659aa). main has one resolved household head: is_resolved_household_head (Person: the eldest member the is_household_head input flags, else the eldest member) and benunit_contains_household_head (BenUnit, defined from it). No formula outside is_resolved_household_head reads is_household_head, and test_only_the_resolved_head_reads_the_flag in policyengine_uk/tests/test_household_head_agreement_properties.py enforces that.

This PR still adds formulas that read the raw flag:

• policyengine_uk/variables/gov/local_authorities/council_tax_reduction/council_tax_reduction_individual_non_dep_deduction_eligible.py: person("is_household_head", period)

Each needs to read the resolved head instead:

• family level: benunit.any(person("is_household_head", period)) becomes benunit("benunit_contains_household_head", period), and person.benunit.any(person("is_household_head", period)) becomes person.benunit("benunit_contains_household_head", period);
• person level, only where the formula needs the head as a person: person("is_household_head", period) becomes person("is_resolved_household_head", period).

test_only_the_resolved_head_reads_the_flag fails until every such read is moved. Please also add each variable you move to OUTPUTS in that test file, so its metamorphic test (flags matter only through the resolved head) computes it. Test inputs that set is_household_head are fine as they are.

[MaxGhenis]

Cross-reference from #2027 (a maintainer review there, 5 October, raised this household).

#2027 (head 360aef868) changes _legacy.py's non-dependant exemption for Income Support, income-based JSA and income-related ESA from the benefit unit's totals to is_on_income_support / is_on_income_based_jsa / is_on_income_related_esa. A person is on the award when it is payable to them (Default Scheme Sch para 2(3)-(4)); of a couple, only the payee is.

The household: Merton, a non-dependant couple. One reports £5,000 of income-related ESA; the other works 20 hours on £15,000.

• This PR alone exempts both: no deduction.
• With Count only the claimant's and partner's legacy awards in means tests and passports #2027, the payee is exempt and the partner pays £10.60 × 52 = £551.20 on joint income of £288.46 a week (para 30(3), (4)). Count only the claimant's and partner's legacy awards in means tests and passports #2027 now has this as a YAML case (2027, in legacy_award_readers/council_tax_reduction_passports.yaml).

The resolution the reviewer proposed: when this PR merges main after #2027, read is_on_* for the IS, JSA and ESA limbs, and keep this PR's claimant-or-partner gate on the Pension Credit and UC limbs. The conflict will be at _legacy.py around the income_based_benefit block.

[MaxGhenis]

Independent review (GPT-6.1 Sol, UK hub sweep, 2026-10-12): REQUEST_CHANGES at 663a5b733. Blockers 1 and 4 are local-scheme readings the texts leave open; they're queued for Max as d1398. This PR has no live owner session. The hub defers it until #2007 lands (same non-dependant code), then adopts it as a Subfleet build with Max's ruling.

VERDICT: REQUEST_CHANGES
Head reviewed: 663a5b7

1. [blocker] Resolve the UC exemption interpretation. _legacy.py:184 uses the couple’s combined earnings for both members’ exemptions. Merton paragraph 30(8)(c) refers to the person’s earnings within an award-calculation condition. The PR body explicitly acknowledges the competing personal-income reading. Fix: obtain Max’s methodology decision, reconcile it with Apply Housing Benefit and national Council Tax Reduction non-dependant deductions as legislated #2007, and pin the chosen treatment with one-earner couple tests.

2. [blocker] Payment alone does not exclude a non-dependant. council_tax_reduction_individual_non_dep_deduction_eligible.py:50 excludes everyone reporting boarder or lodger payments. However, Merton paragraph 9(3)(a) retains non-dependant status when the payment recipient is a close relative or the agreement is noncommercial. Fix: apply those exceptions explicitly, or obtain Max’s decision on the missing relationship information. Add regression coverage across the national and devolved schemes because this eligibility variable is shared.

3. [blocker] Integrate current main’s overlapping corrections. The three-reference merge-tree reports conflicts in both changed production files against main 3f174d07ec03a9d05ca626939442442ddc23c87e. _legacy.py:169 still references the household exemption deleted by merged Assess each Council Tax Reduction claim under its own family's scheme and exemption #2015; its aggregation lacks main’s per-applicant exemption guard. It also retains couple-wide legacy-benefit receipt, while eligibility:48 newly reads the raw household-head flag. Fix: rebase while preserving main’s claimant-specific scheme/exemption, individual payee predicates, and resolved-head semantics. Update the oracle’s household exemption:608 accordingly.

4. [blocker] Westminster’s UC couple rule lacks decisive support. The new oracle:473 assumes one deduction for a UC couple. Westminster’s published summary identifies the Default Scheme as its basis but does not specify this departure; Default Scheme paragraph 30(3) contains a UC exception. Fix: establish the operative Westminster provision and obtain Max’s decision before asserting that no exception applies.

5. [should-fix] The oracle does not establish the claimed conservation. test_benefit_unit_non_dependant_properties.py:703 counts every liable person but assigns one share per benefit unit. A claimant couple plus a lone sharer produces shares [1/3, 1/3]: a £691.60 deduction becomes £461.07 across the claims. Fix: reconcile the partner treatment with each council’s provisions, including Oxford paragraphs 41 and 45, then add an explicit conservation assertion or qualify the PR’s invariant.

6. [should-fix] Supply a main-versus-final-head impact run. For the changes at _legacy.py:84, the impact section reports real enhanced-FRS runs, but compares stacked parent 270412d with intermediate head 570f163, followed by a separate revision comparison. Fix: after integration, provide current-main versus final-head Microsimulation results, full SHAs, dataset identity/checksum, and reproducible commands and outputs.

Validation: 51 focused YAML cases passed serially after checking compressor usage below 30 GB. Python property tests could not collect because Hypothesis was unavailable; xdist was also unavailable. Ruff lint and formatting checks passed. No tests were weakened, skipped or xfailed by this PR, and no protected infrastructure files changed. Both requested gh reads failed to connect; the PR body and file list were retrieved through the browser.

[MaxGhenis]

UK hub takeover for the Budget fix sprint (Max, 21 Oct). The owner session local_300ba566 has been idle since mid-October. The hub woke it on 21 Oct at 23:58Z, and it did not start. To land this before the Budget model locks (the first pe-uk release cut by about 12:00Z Thu 22 Oct), the hub has taken it over as build 20261021-211255-sprint-2077, which merges main, re-tests, pushes as a fast-forward and marks it ready. The hub then reviews it and lands it through the merge queue.

If the owner session wakes, please don't push to this branch; comment here instead, so there's only one writer.

🤖 Generated with Claude Code

[MaxGhenis]

UK hub build sprint-2077b: hand-off at cf0475ddb

The branch is a fast-forward of 663a5b733: same author, no force-push. The base is still #2017 (in-unit-non-dep-deductions), which sits on #2007.

• Merges: Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017 at 3efa8bd60 (which carries Apply Housing Benefit and national Council Tax Reduction non-dependant deductions as legislated #2007 at 4a0935b73 and main at 76cfc9e79), with four conflicts resolved. Then main at 9d81a5dfa, which merged cleanly.
• Review fixes: all six Sol r1 findings and all six maintainer points are addressed, plus the resolved-head rule. The PR body lists each. Four readings are now session rulings: d1398's two (UC exemption on the person's own earnings; Westminster follows the Default Scheme's para 30(3) UC exception), State Pension Credit read by payee, and the close-relative presumption. They are queued for RULINGS.md.
• New issue: Treat a close relative who pays board as a non-dependant (reg 9(3)(a)) once the model has a relationship input #2559, for a close relative who pays board when no relationship input exists.

Tests (local, locked venv):

• YAML: all 64 files that touch CTR or non-dependants pass, 874 of 874, at the final model code. Against the parent (Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017 merged with main, 7ba613fb9), 21 of this head's cases fail, including all three reproducers.
• Property tests (-n 4): 62 of 62 pass. That's the four core non-dependant files (17), with the ported local properties 5-6 and the new conservation assertion, plus eight further CTR property files (45).
• uvx ruff@latest (0.17.1) format and check are clean. .github/check_fix_pr.py, run locally on the diff against main, passes with 23 changed tests.

Impact (Aggregate impact workflow, certified enhanced FRS, dispatched because this base gets no PR CI):

• This PR's own change, against Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017 merged with main (run 39732669012): no household's net income changes in any year, and nothing is flagged.
• The whole stack against main (run 39732671972): government spending +£81.1m (2025-26) to +£95.7m (2031-32), made up of UC +£57.5m to +£65.0m, HB +£17.3m to +£20.4m and CTR +£6.3m to +£10.2m. 0 checks broken and 11 flags (deciles, child relative poverty), all from Apply Housing Benefit and national Council Tax Reduction non-dependant deductions as legislated #2007 and Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017.
• Both runs are at aaf01f968; the later commits change only tests and a comment.

Open items:

• Landing order: Apply Housing Benefit and national Council Tax Reduction non-dependant deductions as legislated #2007, then Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017, then this. No CI runs until the base is main. Fix evidence then reads the body's three Reproducer: lines.
• If Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017 merges main before landing, main's IIDB head-alone case fails on Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017 as it stands: it expects 1,466.368, and Charge non-dependant deductions for non-dependants within the claimant's benefit unit #2017 gives 1,195.968. This PR carries the update.
• Oxford paras 41 and 45 (apportionment) were not re-read. Every council uses main's per-person joint-liability share.
• Follow-up: the local schemes band on their own gross-income list, not Apply Housing Benefit and national Council Tax Reduction non-dependant deductions as legislated #2007's non_dependant_weekly_gross_income.
• No independent review was run by this build; it's the hub's, at this head. I haven't merged anything.

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