Guide

Capital Gains Tax Reporting Deadlines 2026/27

Written by James Whitfield · Updated October 2026 Checked against 2026/27 HMRC rates

There are two clocks, and mixing them up is the most expensive mistake in CGT. Sell a UK residential property that isn't your main home and you have just 60 days from completion to report and pay.¹ Everything else - shares, crypto, business assets - goes through Self Assessment by the following 31 January.² Miss the 60-day date and the £100 penalty is automatic, even on a small gain.

Key takeaways

UK residential property with CGT due: report and pay within 60 days of completion (not exchange).¹
Shares, crypto and other assets: report via Self Assessment by 31 January after the tax year - for 2026/27 that's 31 January 2028.²
Late 60-day filing means an automatic £100 penalty, then more, plus interest on unpaid tax.¹
If you're in Self Assessment, you must also report a disposal when total proceeds exceed £50,000, even if no tax is due.
Never filed before? Register for Self Assessment by 5 October after the tax year.

UK residential property: 60-day rule

If you sell a UK residential property and CGT is due, you must:

Report the gain using HMRC's online "Report and pay CGT on UK property" service
Pay the estimated CGT
Do both within 60 days of the date of completion

The 60-day rule has applied since 27 October 2021 (previously 30 days). The deadline runs from completion, not exchange of contracts.

Miss the 60-day deadline and you get an automatic late-filing penalty. Interest also accrues on unpaid tax from day 61. The penalty starts at £100 for up to six months late, and increases beyond that.

Other assets: Self Assessment

For gains on shares, funds, crypto, non-UK-residential property, and other assets, you report through Self Assessment:

File your Self Assessment tax return by 31 January following the end of the tax year
Pay the CGT by the same 31 January deadline
For 2026/27 (ending 5 April 2027), the deadline is 31 January 2028

If you do not normally file Self Assessment, you may need to register with HMRC. The registration deadline is generally 5 October following the tax year in which the gain arose.

When you may need to report even with no CGT due

If you're already registered for Self Assessment, you have to report a disposal even when there's no tax to pay if your total proceeds for the year are more than £50,000. This is a proceeds test, not a gain test - so a large sale that made only a small profit can still need reporting. (This fixed £50,000 threshold replaced the old "four times the annual exempt amount" rule from 2023/24 onwards.) You should also report a disposal where:

The gain is above the £3,000 exempt amount, so CGT is actually due
You want to record a loss to carry forward - claiming it protects future relief

If you're not in Self Assessment and no CGT is due, you generally don't need to report a share or fund disposal at all. Check the current GOV.UK guidance or speak to a tax adviser if you're unsure.

Worked example — second-home completion on 10 June 2026

Completion date (the clock starts here)	10 Jun 2026
60 days later
Report and pay CGT online by	9 Aug 2026
Also include the gain on your 2026/27 return by	31 Jan 2028
Miss the 60-day date: automatic penalty	£100+

The 60-day payment is a payment on account - your Self Assessment return later reconciles the final figure and credits what you've already paid.

Reporting a loss

Losses are claimed through your Self Assessment return. If you do not file Self Assessment, write to HMRC to claim the loss. The deadline is four years from the end of the tax year the loss arose. For a 2026/27 loss, that is 5 April 2031.

Without claiming, the loss cannot offset future gains. You pay nothing when reporting a loss - it is purely a record-keeping step that protects your ability to use it later.

Records you need to keep

Keep the following for at least five years after the 31 January Self Assessment deadline for the relevant year (longer if you are still using losses from that year):

Completion statements or contract notes showing purchase and sale prices
Solicitor invoices confirming buying and selling legal fees
Estate agent invoices for selling costs
Receipts for capital improvement works
SDLT or LBTT returns (for property purchases)
Correspondence about probate valuations (for inherited assets)

Common mistakes

Confusing the completion date with exchange of contracts - the 60-day clock runs from completion
Assuming the 60-day payment covers Self Assessment - you still need to include the disposal on your tax return
Not registering for Self Assessment in time - the registration deadline can be months before the filing deadline
Losing records from the original purchase, which are needed years later to prove your base cost
Not claiming losses because there is no tax to pay - unclaimed losses expire after four years

Estimate your CGT before the deadline

Use the calculator to get a CGT estimate to help you prepare your 60-day payment or Self Assessment return.

Open the CGT calculator

Frequently asked questions

When must I report a residential property CGT gain?

Within 60 days of the completion date if CGT is due. You report via HMRC's online "Report and pay CGT on UK property" service. You must also include the disposal on your Self Assessment return for the relevant tax year.

What if I make a loss on a property sale?

If no CGT is due - because the gain is a loss, or is fully covered by the annual exempt amount - you are generally not required to use the 60-day service. However, if you want to carry a loss forward, you need to claim it via Self Assessment or by writing to HMRC within four years. Check current GOV.UK guidance for specific reporting requirements based on your total proceeds.

Does the 60-day payment settle my Self Assessment bill?

The 60-day payment is a payment on account. When you complete your Self Assessment return, HMRC will calculate the final CGT liability and credit the payment already made. If you overpaid, you will receive a refund. If there is a shortfall (e.g. because your actual income that year meant a higher rate applied), you pay the difference by 31 January.

What records do I need to keep for CGT?

Keep purchase completion statements, legal fee invoices, improvement receipts, sale contracts and estate agent invoices. Retain these for at least five years after the 31 January Self Assessment filing deadline for the year of disposal. For inherited assets, also keep the probate valuation.

What if I have never filed a Self Assessment return?

You will need to register with HMRC for Self Assessment. The registration deadline is generally 5 October following the tax year in which the disposal occurred. For a 2026/27 disposal, register by 5 October 2027. HMRC will then issue a Unique Taxpayer Reference (UTR) and you can file your return by 31 January 2028.

This page is for general information only and is not financial, tax or legal advice. Reporting deadlines and requirements can change - always check current GOV.UK guidance or consult a qualified tax adviser for your specific circumstances.

PDF guide · £4.99 · 2026/27

Capital Gains Tax Survival Pack

Miss the 60-day deadline and the penalty is automatic - even if the gain is small. This PDF walks you through what to do and when.

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Sources & references

The rates, allowances and rules in this guide are drawn from the official HMRC and GOV.UK sources below, checked for the 2026/27 tax year. Each link opens the relevant government page in a new tab.

Verified against published HMRC and GOV.UK guidance.