Private Residence Relief and Joint Ownership: The Spousal Election and the One-Residence Rule

Sell a jointly owned home and Private Residence Relief usually wipes out the gain, but two cross-rules in the legislation can quietly cost a married couple a chunk of that relief if you do not handle them in time. PRR is the single largest capital gains tax relief in the UK code, and on a jointly owned home it works at owner level: you and your co-owner each claim relief on your own share of the gain by reference to your own qualifying occupation as the only or main residence. Most of that is straightforward. The traps sit in the rules that limit a married couple to one main residence at a time, the formal nomination election that lets you choose which residence qualifies when you own more than one, and the assumption (wrong, and expensive if you act on it) that a Form 17 income split also reshapes your PRR.

Here is how PRR is computed on a jointly owned home, how the s.222(5) nomination election works in practice, how the s.222(6) one-residence-per-couple rule bites for spouses (and not for cohabitees), why Form 17 leaves your PRR untouched, and the inter-spouse no-gain-no-loss route for moving base cost before a disposal where one of you is sitting on more of the gain than the other.

PRR at owner level: each joint owner claims separately

TCGA 1992 s.222 gives the entitlement to PRR; s.223 sets the computation. The relief goes to the individual disposing of an interest in a dwelling that has been their only or main residence at some point during the ownership period. Where two of you jointly own the same dwelling, each of you is an "individual" for s.222, and each of you works out your own PRR.

Your per-owner computation runs like this:

• You take the gain on your share (typically 50% of the total gain for equal joint owners, or your relevant share if you hold as tenants in common with declared shares).
• You identify your own qualifying period of occupation as the only or main residence over the ownership period. The final 9 months of ownership count as occupation under s.223(2)(a) whether or not you actually lived there.
• Your relief is the proportion of your gain that your qualifying period bears to the total ownership period.
• You report any residual non-relieved gain on your own self-assessment return, with your own annual exempt amount and your own rate-band capacity.

If you have both lived in the property as your main residence throughout the ownership period, you each get full relief. It only gets interesting where qualifying occupation differs between you, or where you own more than one residence.

The s.222(5) main-residence nomination election

If you own two or more residences (whether jointly or separately), only one of them can be your main residence at any one time for PRR. You tell HMRC which one by a written notice under s.222(5)(a).

How it works:

• Form of notice. A written notice to HMRC, identifying the nominated property and the period from which the nomination takes effect. There is no prescribed form, though CG64485 sets out HMRC's working position.
• 2-year window. You must give the notice within 2 years from the beginning of the period it covers. If you have just bought a second residence, the practical anchor is the acquisition date of that second property: your 2-year window runs from there.
• Joint signature for couples. Under s.222(5)(b), where the notice affects both you and your spouse or civil partner, you must both give it. A nomination signed by only one of you is invalid.
• Variation. You can vary a nomination by a further notice, but only for periods beginning no earlier than 2 years before that further notice (s.222(5)(b) tail). This is the "flipping" mechanism, and the lookback is limited.
• No valid nomination. If you make none and the 2-year window has lapsed, your main residence is decided on the facts of occupation. HMRC treats the property you have factually used most as the main residence, and in close cases that gets argued.

The nomination is the most under-used PRR planning tool in practice. If you own a primary home and a holiday cottage and the cottage has appreciated significantly, nominating the cottage as your main residence for a short period (then re-nominating the primary home) can produce real PRR on the cottage when you sell. The discipline is the 2-year window: the nomination has to be in place before you dispose, with documentary evidence of when you made it.

The s.222(6) one-residence-per-couple rule

The rule that does most of the heavy lifting for couples is in s.222(6): "There can only be one residence or main residence for both, so long as living together." It applies to spouses and civil partners. While you are living together you have one main residence between you, not one each.

What that means in practice:

• You cannot park PRR on two properties at once. If you both live in property A throughout the year, only property A qualifies. Your spouse cannot claim the other residence as their main residence to widen your PRR coverage.
• Pre-marriage arrangements end at marriage. If you each owned and occupied your own property before marriage, you may each have separately qualified for PRR on your respective homes. From marriage forward the s.222(6) rule applies and only one of the two qualifies. Your 2-year nomination window then runs from the date of marriage (or from the date s.222(6) first applies to you).
• Living together is the test, not legal status. The rule applies "so long as living together", so on separation it stops applying and you can each again have your own main residence. The s.225B post-separation extension (below) preserves PRR for the spouse who moves out, but the underlying s.222(6) one-residence constraint lifts at separation.
• Unmarried cohabitees are NOT within the rule. Two cohabitees in a long-term relationship, each owning a separate property, each get their own PRR on their respective main residence. The s.222(6) rule does not apply to them.

This is one of the rare points where unmarried co-owners come out ahead of married spouses. If you are weighing marriage against cohabitation partly because of PRR coverage on two properties, marriage does pull you into the s.222(6) constraint, so go in eyes open.

Worked example: Hartley and Singh, £950k joint disposal with a letting interlude

Hartley and Singh are a married couple who bought a London house in May 2010 for £400,000 as their main residence. They lived there continuously until May 2021, when they moved out and let the property to tenants for 5 years. In May 2026 they sell the property for £950,000. The property is in joint names as tenants in common in equal shares (deed of trust dated May 2010, 50/50 beneficial split).

Each spouse's CGT computation:

• Gross gain (each): £275,000 (50% of £550,000 total gain after typical costs).
• Ownership period: May 2010 to May 2026 = 16 years (192 months).
• Qualifying occupation (each): May 2010 to May 2021 = 11 years (132 months), plus the final 9 months of ownership under s.223(2)(a) = 141 months total qualifying.
• Letting period not deemed occupation: May 2021 to August 2025 = 51 months (the last 9 months of the letting period are within the final-9-months deeming).
• PRR fraction: 141 / 192 = 73.4%.
• PRR relieved gain (each): £275,000 × 73.4% = £201,875.
• Non-relieved gain (each): £275,000 − £201,875 = £73,125.
• Less annual exempt amount (each, 2026/27): £3,000. Net taxable gain each: £70,125.
• CGT (each, assuming higher-rate band capacity used by other income): £70,125 × 24% = £16,830.
• Total household CGT: approximately £33,660.

Two cross-checks for this example:

• Letting relief was abolished from 6 April 2020 except where you are in shared occupation with the tenant. Hartley and Singh do not get the former s.223B letting relief; the 5-year letting period is not covered by any further relief beyond the final-9-month deeming.
• Form 17 status is irrelevant. Hartley and Singh's income split during the letting period (whether 50/50 by default or unequal by Form 17) does not affect the PRR computation. PRR follows actual residence, not income share; the 50/50 beneficial split governs the CGT share, but the qualifying-period analysis is identical for both spouses.

Form 17 and PRR: independent mechanics

People often assume a Form 17 election to a 75/25 income split also reshapes their PRR. It does not. Form 17 works on rental income tax under ITA 2007 s.836/s.837; PRR is a CGT relief under TCGA 1992 s.222/s.223. The two are independent. For PRR, what matters is this:

• Beneficial share governs the CGT share. If your deed of trust gives you 75/25 beneficial shares (and Form 17 has declared that split for income tax), the CGT computation on disposal uses the same 75/25 split: the higher-share spouse has 75% of the gain, the lower-share spouse 25%.
• Qualifying occupation is per owner. Each spouse's PRR is worked out by reference to their own qualifying occupation. A 75/25 beneficial share changes the size of each spouse's gain; it does not change either spouse's qualifying period.
• The relief is computed independently for each spouse. Where you both qualify throughout, you both get full PRR on your respective shares. Where one spouse's qualifying period is shorter (overseas work, say), only that spouse's PRR is reduced.

The trap is reading Form 17 as a CGT election. It is not. The Form 17 mechanic sets out how the income-tax declaration itself works.

Inter-spouse base-cost shifts under s.58

If one of you has more of the gain than the other (because the property was originally owned solely by that spouse, or because your beneficial shares are unequal), you can rebalance before disposal using the TCGA 1992 s.58 no-gain-no-loss rule. Transferring 50% beneficial interest from the higher-gain spouse to the other before you sell:

• Triggers no CGT on the transfer itself (s.58 no-gain-no-loss; the receiving spouse inherits the original base cost).
• Splits the eventual gain on disposal between you, so each of you uses your own annual exempt amount (currently £3,000) and your own basic-rate band capacity.
• Maximises the PRR claim across both of you, provided you both have qualifying occupation; the receiving spouse must have lived in the property as their only or main residence to qualify.

Timing matters. The s.58 transfer must be by deed of trust (the same document mechanic set out on the declaration of trust page), and the receiving spouse must have qualifying occupation. If that spouse has never lived in the property (because it is a former rental the other spouse inherited, say), no PRR is available on their share however you rebalance under s.58.

Unmarried co-owners with separate main residences

If you and your partner each own and occupy your own primary home and you are not married or in a civil partnership, the s.222(6) one-residence constraint does not touch you. Each of you claims PRR on your own main residence on disposal, regardless of the cohabiting relationship.

The PRR computation is the same per-owner exercise as for spouses, just without the s.222(6) cross-residence limitation. If you later marry or form a civil partnership, s.222(6) applies from that date; if both properties stay in joint use you must nominate one as the main residence within 2 years of the marriage or partnership.

Worked example. Donaldson owns a flat in Manchester that has been their main residence since 2015. Asare owns a house in Birmingham that has been their main residence since 2018. They cohabit informally, alternating between the two properties but each keeping their own primary home for council tax, registered address and day-to-day life. Each disposes of their respective property in 2027:

• Donaldson sells the Manchester flat: full PRR; no CGT.
• Asare sells the Birmingham house: full PRR; no CGT.
• The s.222(6) one-residence rule does not apply (no marriage, no civil partnership). Each main residence stands on its own facts.

The wider tax position for unmarried co-owners, including how you split rental income, is covered separately.

Post-separation PRR: the s.225B extension

When you separate, one of you typically moves out of the family home, which is then held for a while as the dissolution settlement is worked out. TCGA 1992 s.225B deems the spouse who leaves to have carried on occupying the family home for PRR purposes, where the home is later transferred to the spouse who stayed under a court order or formal separation agreement.

The extension was widened by the Finance (No. 2) Act 2023 (in force from 6 April 2023), alongside the parallel widening of the s.58 no-gain-no-loss rule. So if you are the one who moves out, the period between your departure and the eventual transfer stays within PRR coverage, provided that transfer goes to your spouse under the right kind of order or agreement. Outside those conditions, your PRR ends on the date you move out (subject to the final-9-month deeming).

A second strand of s.225B deals with the case where, after separation, you keep a beneficial interest in the family home that your spouse and any children carry on occupying. If the eventual sale is to a third party rather than to your spouse, s.225B can still preserve PRR on your share for the post-separation period, provided the property stays your spouse's main residence and the sale proceeds are paid out in line with the dissolution settlement. The conditions are technical and the documentation matters; HMRC's working position in CG65356 et seq. sets out the qualifying conditions in detail.

s.225B is the third leg of the post-separation tax framework, alongside the s.58 three-year window for CGT-free transfers and the s.18 IHT spousal exemption that runs until dissolution is final. Coordinating all three across a dissolution settlement is the standard advice. Where the settlement involves both a transfer of the family home and a related transfer of a second residence (or a let property), model the sequencing of the transfers, the s.222(5) nomination position and the s.58 election framework before any deed is signed.

Related reading and the points that matter

If you want the underlying rules in more detail:

• For the underlying s.222/s.223 relief for individual owners, see Private Residence Relief for landlords.
• For the s.222(5) nomination in detail when you own more than one residence, see the main residence election for two properties.
• For the per-month fraction in step-by-step worked form, see the PRR calculation on a former home.
• For the s.58 no-gain-no-loss route in depth, including the Finance (No. 2) 2023 extension for post-separation transfers, see CGT on property transfers between spouses.

The joint-ownership points to hold on to: PRR is computed per owner, not per property; the s.222(6) one-residence rule constrains spouses but not cohabitees; a s.222(5) nomination must be made within 2 years and signed by both of you where it affects you both; Form 17 and PRR are independent and easy to confuse; and the s.58 route lets you rebalance base cost before disposal, but the receiving spouse needs their own qualifying occupation to claim PRR on the new share.