Sold a Rental Property? The '60-Day Rule' Trap That Leads to Instant HMRC Fines

⚠️ 2026 Deadline Warning: The Capital Gains Tax (CGT) annual allowance remains frozen at a historically low £3,000. This means almost any property sale now triggers a tax liability, making the "60-Day Rule" more relevant than ever.

🏚️ The "Next Year" Myth

You just sold your rental property (Buy-to-Let) or holiday home for a decent profit. You think: "I'll declare this on my normal Self Assessment tax return next January."

STOP. You are walking into an automatic penalty trap.

Under current UK rules, you no longer have until the end of the tax year. You have exactly 60 days from the completion date to report the sale online AND pay the estimated Capital Gains Tax to HMRC.

Sold a Rental Property?

If you miss this deadline, HMRC charges immediate late filing penalties and interest. Shockingly, many conveyancing solicitors still fail to explicitly warn their clients about this tax deadline.

Does This Apply to Me?

This rule specifically targets UK Residential Property where a taxable gain arises.

📋 The Checklist:

• Main Home: Exempt. If you lived there as your main residence for the entire ownership period (Private Residence Relief), you pay nothing and file nothing.
• Buy-to-Let / Second Home: MUST REPORT within 60 days if your profit exceeds the allowance (£3,000).
• Non-Residents: MUST REPORT within 60 days even if you make a loss or have no tax to pay.

Clock Starts on "Completion"

Be careful with dates. While the tax amount is calculated based on the "Exchange of Contracts" date, the 60-day reporting clock starts ticking from the Completion Date (when keys are handed over).

Action	Penalty
Late Filing (Day 61)	£100 automatic fine (even if tax is paid).
6 Months Late	Additional £300 or 5% of tax due (whichever is higher).
Late Payment	Daily Interest accrues from Day 61 onwards.

The "Separate Account" Hurdle

You cannot just log in to your standard Self Assessment portal. You must create a dedicated "Capital Gains Tax on UK Property" account.

This is a separate digital system. If you do not have a Government Gateway ID, setting one up can take up to a week—so do not leave this until Day 59!

Chief Editor’s Verdict

Conveyancers handle the legal transfer of the deed, not your personal tax liabilities. They often assume your accountant will handle the CGT, while your accountant assumes the lawyer told you.

If you sold a property recently, check your calendar immediately. If you are approaching Day 60, prioritize filing this return today. The fines are automated and ruthless.

[UK Tax Disclaimer]
Tax rules, including the Annual Exempt Amount and CGT rates (18%/24% for residential property as of late 2024/25), are subject to change by the Chancellor. Non-UK residents are subject to different reporting rules. This article is for information purposes only and does not constitute professional tax advice. Always consult with a qualified accountant.