Private Residence Relief is the single largest capital gains tax relief in the UK code, and on a jointly owned home it operates at owner level: each joint owner claims relief on their share of the gain by reference to their own qualifying occupation as the only or main residence. Most of the mechanic is straightforward. The complications come from the cross-rules that limit a married couple to one main residence at a time, the formal nomination election that allows the couple to choose which residence qualifies when more than one is in play, and the interaction between Form 17 (an income-tax declaration) and PRR (a CGT relief that does not care about beneficial share).

This page sets out how PRR is computed on a jointly owned main residence, how the s.222(5) nomination election works in practice, how the s.222(6) one-residence-per-couple rule reshapes the picture for spouses (and not for cohabitees), how Form 17 leaves PRR untouched, and the inter-spouse no-gain-no-loss route for restructuring base cost before disposal where one spouse is sitting on more of the gain than the other.

PRR at owner level: each joint owner claims separately

TCGA 1992 s.222 provides the entitlement to PRR; s.223 provides the computation. The relief is given 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 individuals jointly own the same dwelling, each is an "individual" for s.222 purposes; each computes their own PRR.

The per-owner computation works as follows:

  • Each owner identifies the gain on their share (typically 50% of the total gain for equal joint owners, or the relevant share for tenants in common with declared shares).
  • Each owner identifies their qualifying period of occupation as the only or main residence over the ownership period. The final 9 months of ownership are deemed occupation under s.223(2)(a) regardless of actual residence.
  • The relief is the proportion of the gain that the qualifying period bears to the total ownership period.
  • Each owner reports the residual non-relieved gain (if any) on their own self-assessment return, with their own annual exempt amount and their own rate-band capacity.

Where the couple has lived in the property as their main residence throughout the ownership period, both owners get full relief. The mechanic only becomes interesting where qualifying occupation diverges between the owners, or where the couple owns more than one residence.

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

Where an individual or a couple owns two or more residences (whether jointly or separately), only one of them can qualify as the main residence at any one time for PRR purposes. The mechanism to identify which one is a written notice to HMRC under s.222(5)(a).

The mechanics:

  • Form of notice. A written notice to HMRC, identifying the nominated property and the period from which the nomination has effect. No prescribed form (although CG64485 sets out HMRC's working position).
  • 2-year window. The notice must be given within 2 years from the beginning of the period covered. For a couple who acquires a second residence, the practical anchor is the acquisition date of the second property: the 2-year window runs from there.
  • Joint signature for couples. Under s.222(5)(b), where the notice affects both the individual and their spouse or civil partner, it must be given by both. Single-spouse nominations are invalid for couples.
  • Variation. A nomination can be varied by a further notice, but only in respect of periods beginning no earlier than 2 years before the further notice (s.222(5)(b) tail). This is the so-called "flipping" mechanism but the lookback is limited.
  • Failure to nominate. Where no valid nomination is made and the 2-year window has lapsed, the main residence falls to be determined on the facts of occupation. HMRC will treat the property that the couple has factually used most as the main residence; in close cases the position is disputed.

The nomination is the most under-used PRR planning tool in practice. Where a couple owns a primary home and a holiday cottage and the holiday cottage has appreciated significantly, a properly-timed nomination of the cottage as main residence for a short period (followed by re-nomination of the primary home) can produce material PRR on the cottage disposal. The discipline is the 2-year window: the nomination must be in place before the disposal, with documentary evidence of when it was made.

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

The constraint 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." The rule applies to spouses and civil partners; while they are living together they have one main residence between them, not one each.

The practical consequences:

  • A couple cannot park PRR on two properties simultaneously. Where both spouses live in property A throughout the year, only property A qualifies; the other residence cannot be claimed as a main residence by the other spouse to widen PRR coverage.
  • Pre-marriage arrangements end at marriage. Where each spouse owned and occupied their own property before marriage, both may have separately qualified for PRR on their respective homes. From marriage forward, the s.222(6) rule applies and only one of the two qualifies. The 2-year nomination window runs from the date of marriage (or from the date the s.222(6) rule first applies in the couple's case).
  • Living together is the test, not legal status. The rule applies "so long as living together"; on separation it ceases to apply and each can again have their own main residence. The s.225B post-separation extension (covered below) preserves PRR for the spouse who moves out, but the underlying s.222(6) one-residence constraint is lifted 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.

This is one of the rare points where unmarried co-owners are tax-favoured relative to married spouses. A couple choosing between marriage and cohabitation in part because of PRR coverage on two properties does meet the s.222(6) constraint on marriage; the choice should be made 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 the owner is 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

A common source of confusion is the assumption that a Form 17 election to a 75/25 income split also reshapes the PRR position. It does not. Form 17 operates 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. The relevant facts for PRR are:

  • Beneficial share governs the CGT share. Where the deed of trust gives the spouses 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 computed by reference to their own qualifying occupation. The 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 both spouses qualify throughout, both get full PRR on their respective shares. Where one spouse's qualifying period is shorter (overseas work, for example), only that spouse's PRR is reduced.

For depth on the underlying Form 17 mechanic see our Form 17 mechanic page; the trap to avoid is reading Form 17 as a CGT election. It is not.

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Inter-spouse base-cost shifts under s.58

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

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

The timing matters. The s.58 transfer must be by deed of trust (the document mechanic is covered on our declaration of trust page), and the receiving spouse must have qualifying occupation. Where the receiving spouse has never lived in the property (because it is a former rental that was inherited by the other spouse, for example), no PRR is available on the receiving spouse's share regardless of the s.58 rebalancing.

Unmarried co-owners with separate main residences

Two cohabitees who each own and occupy their own primary home benefit from the absence of the s.222(6) one-residence constraint. Each claims PRR on their own main residence on disposal, regardless of the cohabiting relationship.

The PRR computation is the same per-owner exercise as for spouses, but without the s.222(6) cross-residence limitation. Where the two cohabitees later marry or form a civil partnership, the s.222(6) rule applies from that date; if both properties remain in joint use the couple must nominate one as the main residence within 2 years of the marriage / 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 maintaining their own primary home for council tax, registered address, and life-admin purposes. 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.

For full coverage of the unmarried co-owner tax position, see our unmarried co-owners page.

Post-separation PRR: the s.225B extension

When spouses separate, one typically moves out of the family home; the family home is then owned for some period thereafter while the dissolution settlement is worked out. TCGA 1992 s.225B deems the departing spouse to have continued to occupy the family home for PRR purposes where the home is later transferred to the resident spouse 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. The practical effect for separating spouses is that the period between departure and eventual transfer remains within PRR coverage, provided the eventual transfer is to the other spouse under the right kind of order or agreement. Outside those conditions the departing spouse's PRR ends on the date they move out (subject to the final-9-month deeming).

A second strand of s.225B addresses the situation where, after separation, the departing spouse continues to have a beneficial interest in the family home that the other spouse and any children continue to occupy. Where the eventual disposal is to a third party (and not to the resident spouse), s.225B can still preserve PRR on the departing spouse's share for the post-separation period, provided the property continues to be the resident spouse's main residence and the eventual disposal proceeds are paid out in accordance 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.

The s.225B route is therefore 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 continues until dissolution is final. Coordinating the three rules across a dissolution settlement is the standard advice. Where the dissolution settlement involves both a transfer of the family home and a related transfer of a second residence (or a let property), the sequencing of the transfers, the s.222(5) nomination position, and the s.58 election framework should be modelled before any deed is signed.

Where this sits in the wider CGT picture

This page is the joint-ownership applied view of Private Residence Relief. The mechanic-depth pages on the site cover the underlying rules in more detail:

The joint-ownership-specific points to take away are: PRR is computed per owner, not per property; the s.222(6) one-residence rule constrains spouses but not cohabitees; the s.222(5) nomination must be made within 2 years and signed jointly where it affects both spouses; Form 17 and PRR are independent mechanics that should not be confused; and the s.58 route is available to rebalance base cost before disposal, but the receiving spouse needs their own qualifying occupation to claim PRR on the new share.