Model a Universal Credit claim by a member of a couple as a single person (UC Regs 2013 reg 3(3))

[MaxGhenis]

Summary

When the other member of a couple cannot be a joint Universal Credit claimant, the member who can claims as a single person (UC Regs 2013 reg 3(3)). #2081 added the input uc_is_ineligible_partner for that other member and used it only for the minimum income floor. This PR models the rest of the award. It follows reg 3(3), which says "regulations 18 (capital limit), 36 (amount of elements) and 22 (deduction of income and work allowance) provide for the calculation of the award in such cases":

• Amounts are a single claimant's (reg 36(3)): the single standard allowance at the claimant's own age. There is no LCWRA or carer element for the other member, who is not "a claimant" (regs 27(1), 29(1)).
• Capital and income are the couple's (regs 18(2), 22(3)). The deduction is what joint claimants would have, so the other member's limited capability for work still gives the work allowance. The model already did this; tests now pin it.
• The claimant must meet the basic conditions. A claimant over State Pension age cannot claim this way (WRA 2012 s.4(1)(b)): the mixed-age route of reg 3(2)(a) is only for joint claimants. The model then treats it as no single claim at all.
• Benefit cap. A childless single claimant has the single cap (£14,753, or £16,967 in London; reg 80A(2), ADM E5007 note 3). The other member's PIP, DLA, carer's allowance, LCWRA, AFCS or contributory ESA does not lift it (reg 83(1), "a claimant"). Their earnings count towards the earnings exception (regs 78(2), 82(1)(a)).
• Shared accommodation rate. A renter under 35 claiming as a single person is a specified renter, judged on their own age and their own disability exception (Sch 4 para 28(2), para 29(5); ADM F3213). The other member is not a non-dependant (para 9(2)(b)).
• Limb (a) is now derived. A member of a couple under 18 to whom the reg 8 minimum age of 16 does not apply is now the ineligible partner by formula (meets_uc_minimum_age_condition). This is ADM E2017's worked example: Jane is 17 and Tom is 19, so "Tom is required to claim for himself as a single person". Limbs (b)-(e) (not in Great Britain, prisoner, reg 19, s.115 IAA 1999) are not observed and stay inputs.

Example, 2026-27: two 30-year-olds, no children, no rent. One cannot be a joint claimant, and that member earns £6,000.

	Joint claimants	Single claim (this PR)
Standard allowance	£666.97 × 12 = £8,003.64	£424.90 × 12 = £5,098.80
Deduction (55% of £6,000, no work allowance)	£3,300	£3,300
Universal Credit	£4,703.64	£1,798.80

Impact: £0 on the Enhanced FRS, as expected. These are real Microsimulation runs on the Enhanced FRS 2024-25 (sha256 e433e532…), one run per package state, every year 2025 to 2030: base 6db0ab118 against branch 649503f7b, then again against 17b9b8a16 after the review fixes. Both branch runs give the same result.

• UC, the benefit cap reduction, Housing Benefit, Pension Credit, Council Tax Reduction, household net income and poverty are unchanged to the penny.
• No benefit unit changes any of the 15 UC, cap and LHA variables compared, or its LHA category.
• The other limbs (prisoner, abroad, reg 19, s.115) are inputs the FRS does not supply, so the input stays false everywhere.
• Limb (a), now derived, never fires. The data have 239 claimant-or-partner records under 18 (351,000 people weighted), and every one is a single 16- or 17-year-old heading their own benefit unit. No couple in the data has a member under 18.
• So the change matters for calculator users who set the input, and for any future data with such couples.

Stack and base

• Stacked on Apply the UC minimum income floor only to claimants subject to all work-related requirements #2081 (uc-mif-work-related-groups, head 94b7129b4). Apply the UC minimum income floor only to claimants subject to all work-related requirements #2081 sits on Apply the UC minimum income floor to net earned income against a net threshold #1973 and Deduct only each person's own tax and NI on earnings from UC earned income #1949.
• Apply the UC minimum income floor only to claimants subject to all work-related requirements #2081 does not yet have main's claimant roles (Replace generic child and adult flags with each programme's legal definitions #1896, is_claimant_or_partner), which rewrote most of the files here. So this branch merges origin/uc-earned-income-own-tax (Deduct only each person's own tax and NI on earnings from UC earned income #1949, which carries main) into Apply the UC minimum income floor only to claimants subject to all work-related requirements #2081 first, at 6db0ab118. That merge had two conflicts, both in Apply the UC minimum income floor to net earned income against a net threshold #1973's files:
  • uc_individual_earned_income.py: kept Apply the UC minimum income floor to net earned income against a net threshold #1973's floor formula, and moved Deduct only each person's own tax and NI on earnings from UC earned income #1949's age-75 limit on relievable pension contributions into uc_individual_earned_income_before_mif.py;
  • a test docstring.
• The PR's base is a branch at 6db0ab118, so the diff shows only this work. Retarget to main once Apply the UC minimum income floor only to claimants subject to all work-related requirements #2081 has merged. CI runs only on PRs into main.

Law (legislation.gov.uk, fetched 2026-10-02)

UC Regs 2013 (https://www.legislation.gov.uk/uksi/2013/376):

3(3) A person who is a member of a couple may make a claim as a single person if the other member of the couple— (a) does not meet the basic condition in section 4(1)(a) (at least 18 years old) and is not a person in respect of whom the minimum age specified in regulation 8 applies; (b) does not meet the basic condition in section 4(1)(c) (in Great Britain); (c) is a prisoner; (d) is a person other than a prisoner in respect of whom entitlement does not arise by virtue of regulation 19 (restrictions on entitlement); or (e) is a person to whom section 115 of the Immigration and Asylum Act 1999 (exclusion from benefits) applies, and regulations 18 (capital limit), 36 (amount of elements) and 22 (deduction of income and work allowance) provide for the calculation of the award in such cases.

18(2) In a case where the claimant is a member of a couple, but makes a claim as a single person, the claimant's capital is to be treated as including the capital of the other member of the couple.

22(3) In the case of an award where the claimant is a member of a couple, but makes a claim as a single person, the amount to be deducted from the maximum amount in accordance with section 8(3) of the Act is the same as the amount that would be deducted in accordance with paragraph (1) if the couple were joint claimants.

Reg 22(1)(b)(i) has no work allowance only "where a single claimant does not have, or neither of joint claimants has, responsibility for a child or qualifying young person or limited capability for work".

36(3) In the case of an award where the claimant is a member of a couple, but claims as a single person, the amounts are those shown in the table for a single claimant.

27(1) An award of universal credit is to include an amount in respect of the fact that a claimant has limited capability for work and work-related activity ("the LCWRA element").

29(1) An award of universal credit is to include an amount ("the carer element") ... where a claimant has regular and substantial caring responsibilities for a severely disabled person ...

32(1) The work condition is met in respect of an assessment period if— (a) the claimant is in paid work ...; and (b) if the claimant is a member of a couple (whether claiming jointly or as a single person), the other member is either in paid work or is unable to provide childcare because that person— (i) has limited capability for work, (ii) has regular and substantial caring responsibilities for a severely disabled person, or (iii) is temporarily absent from the claimant's household.

78(2) In this Part "couple" means— (a) joint claimants; or (b) a single claimant who is a member of a couple within the meaning of section 39 of the Act and the other member of that couple ...

80A(2)(c) £14,753 for a single claimant not resident in Greater London who is not responsible for a child or qualifying young person; (d) £22,020 for— (i) joint claimants not resident in Greater London; (ii) a single claimant not resident in Greater London who is responsible for a child or qualifying young person.

82(1)(a) the claimant's earned income or, if the claimant is a member of a couple, the couple's combined earned income, is equal to or exceeds ...

83(1) The benefit cap does not apply ... where— (a) the LCWRA element is included in the award of universal credit or the claimant is receiving an employment and support allowance that includes the support component; ... (g) a claimant, or a qualifying young person for whom a claimant is responsible, is receiving personal independence payment; ...

Sch 4 para 9(2) A person is a non-dependant if the person normally lives in the accommodation with the renter (or joint renters) and is none of the following— ... (b) where the renter is a member of a couple claiming as a single person, the other member of the couple; ...

Sch 4 para 28(2) The first condition is that the renter is a single person (or a member of a couple claiming as a single person) who— (a) is under 35 years old; and (b) is not an excepted person under paragraph 29.

Welfare Reform Act 2012 s.40 (https://www.legislation.gov.uk/ukpga/2012/5/section/40): "'claimant' means a single claimant or each of joint claimants".

DWP Advice for Decision Making:

• E2017 (https://assets.publishing.service.gov.uk/media/6a0474b6ee62840dba48a1eb/adme2.pdf): for a partner under 18 outside reg 8, or not in GB, "the claim is treated as that of a single person ... The UC standard allowance for a single person is awarded (and, if appropriate, any elements)". Its example: "Tom is required to claim for himself as a single person because Jane is under 18 years old".
• E2031: the award "will still have regard to any earned income, unearned income and capital of the disregarded member of the couple".
• E5007 note 3 (https://assets.publishing.service.gov.uk/media/6a2a631ec39255c595b5068c/adm-chapter-e5.pdf): "Where a member of a couple making a claim for UC as a single person is not responsible for a child or qualifying young person, the relevant amount is that at 1. or 3." These are the single-claimant limits.
• F3213 (https://assets.publishing.service.gov.uk/media/69dfa35553469bbcdf408f00/admf3.pdf): "A specified renter is a renter who is a single person (or member of a couple claiming as a single person) under 35 years old ...".
• F7012 (https://assets.publishing.service.gov.uk/media/696a076c7b7f37aa8e4022d9/adm-ch-f7.pdf): for "a person who is a member of a couple but who is paid as a single person ... the other member has to be in paid work, or fall into the exceptions in F7013".
• The ADM says nothing on the work allowance in this case. The model reads reg 22(3) as covering the whole reg 22(1) deduction, work allowance included, as rulespec-uk's 22.yaml does.

Change

New:

• is_uc_single_or_joint_claimant (Person). The claimant in WRA s.40's sense: is_uc_claimant (the two eldest), less uc_is_ineligible_partner.
• uc_member_of_couple_claims_as_single_person (BenUnit). One member of the couple is the ineligible partner, and the other is a claimant who meets the s.4(1)(a)-(b) age conditions.
• In utils/uc_work_related_requirements.py:
  • other_member_of_single_claim: the partner of such a claimant. A flag with no claimant beside it marks nothing.
  • single_claim_in_rules_shared_with_legacy_benefits and other_member_of_single_claim_in_shared_rules: the same, for the rules Housing Benefit shares, and false for a family claiming legacy benefits.

Changed:

• uc_is_ineligible_partner: has a formula for limb (a) (a couple member who fails meets_uc_minimum_age_condition); still an input for limbs (b)-(e). A member under 16 is treated as within (a) whatever their circumstances. Strictly, reg 3(3)(a) then gives the other member no single claim; the model does not follow that.
• uc_standard_allowance_claimant_type: counts s.40 claimants and uses their ages (reg 36(3)).
• is_uc_eligible: the qualifying claimant must be an s.40 claimant.
• uc_LCWRA_element, uc_carer_element: nothing for the other member of a single claim (regs 27(1), 29(1)). The carer element keeps its benunit_has_carer route.
• is_benefit_cap_single_claimant_rate: true for a single claim without a child (reg 80A(2)), unless the family claims legacy benefits.
• is_benefit_cap_exempt_health_disability, is_benefit_cap_exempt_other: the other member's own benefits, LCWRA, AFCS and contributory ESA lift no cap (reg 83(1)), unless the family claims legacy benefits.
• is_lha_shared_accommodation_rate_specified_renter: applies to a member of a couple claiming as a single person, on the renter's own age and exception (Sch 4 paras 28(2), 29(5)), unless the family claims legacy benefits.
• is_uc_claimant: docstring only, pointing to is_uc_single_or_joint_claimant.
• uc_childcare_work_condition: the claimant must be in work and the other member is tested as a partner (reg 32(1)). Same result as before: both members of a couple must work, and the reg 32(1)(b) exceptions are still not modelled.

Unchanged and already right, now pinned by tests:

• capital (reg 18(2)): uc_assessable_capital counts both members of the couple;
• income and work allowance (reg 22(3)): uc_earned_income, uc_unearned_income and is_uc_work_allowance_eligible read both members;
• the cap earnings exception (reg 82(1)(a)).

Two existing tests change expectation. A couple aged 30 and 17 used to be treated as joint claimants, and benefit_cap.yaml said "UC reg 3(3) permits some couples to claim as singles, not modelled here". The 30-year-old now claims as a single person (ADM E2017), so they get the single cap of £14,753 and the shared accommodation rate. A new sibling case in each file gives the 17-year-old a reg 8(1)(c) circumstance (caring); that couple claims jointly, with the couple cap and no shared rate.

Modelling choices and limits

1. Housing Benefit shares the cap rate, the cap exceptions and the LHA category, but has no single claim by a member of a couple.
   • A family claiming legacy benefits (claims_legacy_benefits: reported CTC, WTC, HB, income-related ESA, IS or income-based JSA) keeps the couple rules there.
   • Otherwise the UC rule applies, which Housing Benefit then shares.
   • The UC award itself does not look at claims_legacy_benefits.
   • A flag with no claimant beside it (a single adult, both members of a couple, or a claimant over State Pension age) changes none of the shared rules; a property test pins that.
2. Limbs (b)-(e) are not observed. The FRS does not record a partner abroad, in prison, in a religious order or subject to immigration control. Only limb (a) arises in the data.
3. Reg 32(1)(b) exceptions (a partner with LCW, caring, or temporarily absent, for example in prison) are still not modelled for any couple. So a single claimant whose partner is away still needs the partner in work for the childcare element.

Tests

• claims_as_single_person.yaml (27 cases). Each expected value is hand-computed from the reg 36, 22 and 80A tables in force for 2026-27 (UC Act 2025, SI 2026/113, SI 2026/148) and NMW Regs reg 4 (£12.71). The cases cover:

  • the standard allowance at the claimant's own age;
  • the Jane/Tom example, with a reg 8 sibling;
  • pension age either way round;
  • capital (two Lifetime ISAs over the limit together);
  • earned and unearned income;
  • the work allowance from the other member's LCW;
  • LCWRA and carer elements either way round;
  • the childcare work condition;
  • the cap rate with and without a child;
  • PIP and the cap either way round, against joint claimants;
  • the earnings exception;
  • the shared accommodation rate by the renter's age and the partner's PIP;
  • a single adult flagged;
  • a family claiming legacy benefits, which keeps the couple cap and no shared rate while its UC award is a single claim.

• test_uc_single_claim_properties.py, 7 Hypothesis properties. Generated couples are calculated three ways: as a single claim, as joint claimants and as the claimant alone. Each property also runs on explicit example families, including ADM E2017's Tom and Jane.

  1. The single standard allowance at the claimant's age.
  2. The single claim's maximum amount equals the claimant-alone maximum. This covers the standard allowance, LCWRA, carer and housing elements and the shared accommodation test.
  3. Earned income, unearned income and the work allowance equal the joint claimants', and the deduction is min(maximum amount, 55% × earned + unearned).
  4. Capital equals the joint claimants'.
  5. The single cap rate applies exactly when there is no child, and the cap exceptions equal the joint claimants' with the other member's own disability, caring and benefits removed.
  6. Limb (a) against the law's own test: under 18 with none of the generated reg 8(1) circumstances, or under 16.
  7. A flag marking no single claim leaves every Housing-Benefit-shared rule as it was.

  A further test, test_examples_reach_the_cases, checks that the examples change each rule they target. Mutation-checked: reverting the LCWRA, standard allowance, cap rate or guard change each fails its property.

• Apply the UC minimum income floor only to claimants subject to all work-related requirements #2081's property fixtures now declare is_claimant_or_partner, as Deduct only each person's own tax and NI on earnings from UC earned income #1949 did in a57caf1. Main's presumption read a generated 18-year-old partner of a 52-year-old as their child, so test_partner_who_cannot_be_a_joint_claimant failed on 6db0ab118 itself.

• Targeted runs on this head: the UC YAML folder; the whole policyengine_uk/tests/policy YAML tree (one process); test_uc_single_claim_properties.py; and these property files: work-related groups, minimum income floor, child and adult definitions, earnings deductions, State Pension, unearned benefits, Lifetime ISA capital, abolish-benefit-cap scenario, UC deductions, rebalancing, Housing Benefit pension age, means-test income and code health. All pass on 17b9b8a16:

  • the YAML tree, 1,755 tests;
  • those property files with test_uc_single_claim_properties.py and the code-health tests, 1,851 tests plus 1 test already marked as an expected failure.

  These were run on a detached copy of the head, so no edit could reach the run.

Coordination with open PRs

• Count only claimants' income in Universal Credit #1978 (claimant-only income). Its is_uc_assessed_claimant keeps the reg 3(3) partner, which is right for income and capital (regs 18(2), 22(3)). Its docstring should say so, and its uc_childcare_work_condition should keep "the s.40 claimant is in work".
• Give the UC LCWRA and carer elements, the work allowance and the benefit cap exceptions on the claimants' circumstances only #1989 (claimant-only elements). Its LCWRA, carer and reg 83 filters should exclude the other member of a single claim (other_member_of_single_claim). Its work allowance should keep them, because reg 22(3) is "as if joint claimants".
• Lift the benefit cap only for the support component and the people HB reg 75F and UC reg 83 name, and cap only the family's benefits #2076 (cap exceptions per HB reg 75F / UC reg 83). It counts is_claimant_or_partner; for UC reg 83 it needs & ~other_member_of_single_claim_in_shared_rules(person, period). Separately, its pension-age cap exception (has_pensioner, any member) has no basis in UC regs 82-83; that predates this PR.
• Give children and couples who cannot share a bedroom their own bedrooms in the LHA size criteria #2080 (Sch 4 para 12 couple room). A reg 3(3) partner is not a joint renter, so the couple gets no room for not being able to share.

Comments on those PRs say the same.

axiom: uk/regulations/uksi/2013/376/18, /22, /32, /90 and schedule/4/paragraph/28 are encoded-correct for this case. Their companion tests are, in order, single_claimant_member_of_couple_includes_other_member_capital, member_of_couple_claiming_as_single_uses_joint_claimant_deduction, couple_claimant_treated_as_paid_work_and_other_member_unable, couple_claiming_as_single_by_regulation_3_3_meets_combined_threshold and renter_meets_all_specified_renter_conditions. The rest is queued:

• Encode UC Regs 2013 regs 3 and 8 (couples; minimum age 16); replace the opaque s.4 minimum-age exception input TheAxiomFoundation/rulespec-uk#355 (addendum) queues reg 3 itself, adds regs 36, 80A, 82, 90 and Sch 4 para 28 to its rewire list, and adds reg 3(3) cases for regs 36, 80A, 27 and 29 and the program spec;
• Encode UC Regs 2013 reg 78(2) (benefit-cap "couple" includes a single claimant's partner) and wire it into reg 82; add Sch 4 para 9(2)(b) companion cases (PE parity: policyengine-uk#2084) TheAxiomFoundation/rulespec-uk#428 queues reg 78(2), its wiring into reg 82, and the Sch 4 para 9(2)(b) cases;
• Encode the benefit cap's specified-benefit exceptions and capped total: HB Regs 2006 regs 75A, 75E, 75F; UC Regs 2013 regs 79, 80, 83; WRA 2007 ss.2, 4 (PE parity: policyengine-uk#2076) TheAxiomFoundation/rulespec-uk#425 gets the reg 83 reg 3(3) cases.
  All are dispatch-ready.

Review: round 1 (independent Opus review via Subfleet, head 649503f7b) asked for changes, with no P1s; every finding is addressed in 17b9b8a16. Round 2 is running.

🤖 Generated with Claude Code

[MaxGhenis]

Coordination with #2088 (updated for #2088's rename of the offer input), which models UC Regs 2013 reg 32 (the childcare work condition's partner exceptions, reg 32(2) treated-as-working, and offers of paid work). Both PRs edit uc_childcare_work_condition.py, so whichever merges second has a conflict there. This is the resolved formula, keeping this PR's reg 3(3) structure:

    def formula(benunit, period, parameters):
        person = benunit.members
        # WRA 2012 s. 40 claimants: a single claimant or each joint claimant.
        claimant = person("is_uc_single_or_joint_claimant", period)
        # Also the other member of a reg. 3(3) single claim, who is tested
        # under reg. 32(1)(b) "whether claiming jointly or as a single person".
        claimant_or_partner = person("is_uc_claimant", period)
        # Reg. 32(2) treats "a claimant" as in paid work, so not the other
        # member of a single claim.
        treated = claimant & person("uc_childcare_treated_as_in_paid_work", period)
        in_paid_work = person("in_work", period) | treated
        meets_claimant_limb = in_paid_work | person(
            "uc_has_offer_of_paid_work_starting_by_end_of_next_assessment_period",
            period,
        )
        meets_other_member_limb = in_paid_work | person(
            "uc_unable_to_provide_childcare", period
        )
        fails_other_member_limb = claimant_or_partner & ~meets_other_member_limb
        others_failing = (
            benunit.project(benunit.sum(fails_other_member_limb))
            - fails_other_member_limb
        )
        return benunit.any(claimant & meets_claimant_limb & (others_failing == 0))

Your two reg 32 cases in claims_as_single_person.yaml. Both keep their results. Neither has an exception, a listed payment or an offer for the ineligible partner.

A case worth adding after the merge. In a reg 3(3) single claim, the claimant works and the other member receives SMP (no work, no exception). Expected: uc_childcare_work_condition: false, because the other member is not a claimant, so reg 32(2)(b) does not treat them as in paid work. In a joint claim the same facts give true (#2088's "a partner on statutory maternity pay with a working claimant").

#2088's property tests (test_uc_childcare_work_condition_properties.py) set is_claimant_or_partner and never uc_is_ineligible_partner, so they should pass unchanged after the merge.

🤖 Generated with Claude Code

[MaxGhenis]

#2089 is stacked on this PR. It gives Universal Credit and Housing Benefit their own benefit cap and LHA shared-accommodation variables and drops the claims_legacy_benefits stopgap:

• reg 3(3) applies to the UC rules directly;
• HB treats the couple as a couple whatever the family claims.

#2089 removes single_claim_in_rules_shared_with_legacy_benefits and other_member_of_single_claim_in_shared_rules. If this PR changes them or their callers after #2089's base (17b9b8a), #2089 will merge the change in.

#2089's landing job waits for this PR to merge.