I sold a property and didn't report it, what happens?

Selling a UK residential property that is not your only or main home usually creates a capital gains tax reporting obligation with a tight 60-day deadline from completion, separate from your annual Self Assessment return. Missing it does not remove the obligation; it just adds penalties and interest on top.

The right response is to file the report now, even late, and pay any tax due promptly. HMRC's system is designed to catch these disposals through Land Registry data, so a late but voluntary filing is far better than waiting to be contacted.

UK residential property disposals by individuals, where capital gains tax is due, must be reported and the tax estimated and paid within 60 days of completion. This sits alongside, but separately from, reporting the disposal again on your Self Assessment return for the relevant tax year.

Late filing penalties apply automatically once the deadline passes, increasing the longer the report remains outstanding, and interest accrues on unpaid tax from the original due date. If HMRC identifies the disposal itself through Land Registry data before you report it, the case is likely to be treated as prompted rather than a voluntary correction.

Where the failure was for a reasonable excuse and put right without unreasonable delay once the excuse ended, penalties can potentially be reduced or removed, but this needs a genuine reasonable excuse recognised by HMRC or the tribunal, not simply an oversight.

Personal property disposals are reported under your own capital gains tax obligations, entirely separate from your company's corporation tax position, even if you also run a property-related business.

If the property was owned by your company rather than personally, the gain falls under corporation tax rules instead, and needs reporting through the company's tax return rather than the 60-day personal regime.

You will owe the capital gains tax itself, a late filing penalty for missing the 60-day window, and interest on the tax from the original due date. The penalty increases the longer the report stays outstanding, so speed matters.

Working out the gain correctly, including allowable costs and any reliefs, often reduces the tax due meaningfully, so professional review can pay for itself. See /fees for our services and included tax investigation insurance.

Do not assume no tax is due without checking. Main residence relief may cover the whole gain in some cases, but only if the specific conditions are met for the whole ownership period.

Avoid waiting until your Self Assessment return is due. The 60-day report and payment obligation is separate and earlier, and the penalty clock starts regardless of your annual filing date.

Do not forget to also include the disposal on your Self Assessment return for the year, even after the 60-day report has been filed, since both obligations apply.