Sell a UK residential property with capital gains tax to pay and you have 60 days from completion to report the gain and pay the tax — through HMRC's online property account, separately from and long before your self assessment return. Miss the window and penalties start at £100 and escalate from there, with interest running on the tax. Years after its introduction, this deadline still ambushes sellers weekly, mostly because solicitors close the file at completion and accountants hear about the sale in January.
Here is who has to file, how the system works, and the traps that generate the penalty letters.
Who must file within 60 days
UK residents: only where a UK residential disposal actually produces tax to pay. Selling your own home, fully covered by private residence relief, needs no return; nor does a disposal whose gain sits within your £3,000 annual exemption or is wiped out by losses you have already realised. But a buy-to-let, a second home, an inherited house sold above probate value — if tax is due, the 60-day clock runs from completion (not exchange).
Non-UK residents: a stricter regime — every disposal of UK land must be reported within 60 days, residential or commercial, direct or via certain property-rich companies, even when no tax is due. The nil-gain, nil-tax filing obligation is the single most-missed rule in this area, and it catches expats selling the old family home constantly.
And the one nobody expects: gifts count. Transfer a rental property to your children and you have disposed of it at market value — tax due, 60-day return due, with no sale proceeds to fund either. (Transfers between spouses and civil partners are no-gain-no-loss rather than tax-free: the recipient inherits the original base cost, so the gain is deferred to their eventual disposal, not erased.) Our guide to gifting property to children covers that side in full.
How the reporting actually works
The return goes through a Capital Gains Tax on UK property account — a standalone HMRC service with its own Government Gateway setup, not part of self assessment. You (or your accountant: agents can be authorised against the account and file for you) report the disposal, the computation and pay the tax in the same 60 days.
The fiddly part is the rate. Residential gains are taxed at 18% within your basic-rate band and 24% above it — which means the return needs an estimate of your total income for the current tax year, months before you know it. Estimate reasonably, document the basis, and the position trues up later: if you file self assessment, the disposal goes on that return too, with the property-account tax credited against the final liability. Overpayments come back; underpayments settle through the return. The property account also allows amendments, which matters more often than you would think — completion statements arrive late, improvement costs surface, probate values get renegotiated.
Getting the computation right
The gain is proceeds minus acquisition cost, purchase and sale costs (legal fees, agent fees, SDLT paid on the way in) and capital improvements — the extension, not the redecorating. The recurring computation issues:
- Inherited property: your base cost is the value at death, not what the deceased paid — often dramatically reducing the gain, and occasionally revealing that the probate value was set carelessly low;
- Partial residence: lived in the property for part of your ownership? Private residence relief covers those years plus the final nine months, pro-rata — the calculation rewards good records of dates;
- Divorce: transfers between separating spouses have their own (now more forgiving) timing rules, but the interaction with the 60-day clock still needs managing;
- Losses: the 60-day payment can only take account of losses on disposals made on or before the completion date of the property sale — a loss crystallised even a week later reduces nothing up front and comes back through a further return or self assessment instead. Sequencing loss sales before completion, not before filing, is the planning point.
Penalties: cheap to avoid, annoying to accrue
The late-filing ladder mirrors self assessment: £100 immediately, potential daily penalties once three months late, and at six and twelve months further charges of £300 or 5% of the tax, whichever is greater — plus interest on late payment throughout. A return that is a year late on a £40,000 liability has built serious money in penalties for what is, at heart, a form.
If you have already missed a deadline — common when nobody told the seller the rule existed — file now rather than waiting for self assessment to surface it. Voluntary catch-up filings with a reasonable-excuse argument land far more softly than the version where HMRC's land-registry data matching finds the sale first, which it reliably does.
Making it routine
The fix for the whole problem is sequencing: get the CGT conversation in before completion, not after. That is when an estimate can be prepared, the property account set up, improvement records assembled and — where the numbers justify it — timing and structuring options are still open: crystallising losses first, spreading disposals across tax years, or checking whether the sale even produces a liability once reliefs are properly counted.
We handle 60-day returns as a fixed-scope service — computation, filing through the property account, and the later self assessment reconciliation — through our CGT planning and compliance team, with property tax advice for landlords disposing of more than one. If completion is already behind you, start counting days and call sooner rather than later.