Principal private residence relief is the reason selling your home does not trigger capital gains tax: a dwelling occupied as your only or main residence throughout ownership is fully relieved, with the final nine months covered whether you live there or not. It is the most valuable relief most people will ever use — and one of the most litigated, because every departure from the simple story (a second home, a rental period, a big garden, a spell abroad) chips away at the relief in ways that surface, expensively, at sale. The Budget speculation about capping it came to nothing: the relief survived November 2025 unchanged. The traps, however, remain.
The core rules
Full relief needs the property to have been your only or main residence throughout the period of ownership. "Residence" means genuine occupation with some quality and permanence — furniture delivered and a fortnight of camping before a sale has failed in tribunal repeatedly — and the final nine months of ownership are always relieved once the property has qualified at some point, extended to 36 months for owners who are disabled or move into care. Partial occupation produces partial relief, apportioned by time: live in a house for ten of twenty years of ownership and (with the final nine months) roughly half the gain is relieved. Grounds of up to half a hectare ride along with the house, more where genuinely required for its reasonable enjoyment.
Absences that still count
The legislation forgives specific gaps, provided the property was your residence before the absence and — broadly — you reoccupy after, with no other property qualifying meanwhile: up to three years of absence for any reason, up to four years working elsewhere in the UK, and unlimited absence working abroad, with the reoccupation requirement relaxed where the job itself prevents returning. Sequenced properly, a decade-long expat posting can leave the family home fully relieved. Sequenced casually — the house let, another home bought, no reoccupation — the same decade becomes taxable, and the difference is planning done before departure rather than after.
Two homes: the election worth real money
With more than one residence, which is your "main" one is a question of fact — unless you take it out of HMRC's hands by nominating, in writing, within two years of each change in your combination of residences. Married couples and civil partners get one main residence between them, which makes the nomination a joint decision with joint consequences.
The election is the most underused piece of paper in private client tax. Once made it can be varied at any time, backdated up to two years — so a well-advised couple with a London flat and a country house can direct the relief toward whichever property carries the larger gain, and even a brief nomination of a second home banks the final-nine-months relief on it. Miss the two-year window and the question reverts to facts and evidence: utility bills, GP registrations, where the children go to school. People lose that argument with houses they genuinely lived in, for want of a one-page letter.
Where the relief leaks
- Letting. Renting out the whole house creates unrelieved periods (beyond the forgiven absences). Letting relief — up to £40,000 per owner — survives only where you share occupation with your tenant, the post-2020 restriction that quietly removed it from virtually every ordinary landlord;
- Development and plots. Selling the garden as a building plot before the house usually works within the permitted area; selling it after the house has gone loses relief entirely, and buying-doing-up-selling as a pattern invites HMRC to tax the whole thing as trading income rather than a relieved gain;
- Trusts and holdover. Where a property came into (or out of) a trust with a s260 holdover claim, PPR on a later sale is barred — the trap that catches "put the house in trust for the kids" plans, covered in our trusts guide;
- Non-residents. Since 2015, a tax year counts toward relief on a UK home only if you (or your spouse) were resident in the property's country or spent at least 90 midnights in it that year (nights across your properties in the same country aggregate) — the rule that removed PPR from most expat landlords without their noticing;
- Quality of occupation. Short, purposeful stays engineered around a sale fail; the tribunals look for a genuine home, not a genuine fortnight.
The compliance edge
Where PPR fully covers a UK resident's sale, there is nothing to file — but non-residents must report every UK property disposal within 60 days regardless of relief or tax due. Where it does not — the let years, the second home, the plot — the disposal lands in the 60-day reporting regime, with the relief calculation done under deadline pressure. The records that make that calculation defensible are dull and decisive: dates of occupation, the nomination letters, evidence of residence for each period. Reconstructing 15 years of living arrangements in 60 days is nobody's best work.
Acumon handles PPR calculations, nominations and disputed-residence cases through our CGT planning team, with property tax covering landlords and second-home owners for whom this relief is a moving part rather than the whole answer. The recurring lesson from the case law: this relief rewards paperwork done at the time — the election, the diary, the forwarding address — far more than argument after the fact.