Telling HMRC about a capital gain

If you make a capital gain it should be entered on the capital gains tax page of your tax return. If you don’t normally receive a tax return, you will need to tell HMRC about the gain by 5 October following the end of the tax year in which you made the gain. HMRC will then send you a tax return. It is better to tell HMRC as soon as possible as this will give you more time to prepare the necessary calculations and complete the return.

If you sell your main residence you do not need to tell HMRC so long as it has always been occupied by you as your main residence. If it has been let out, or left unoccupied for longer than three years, you should notify HMRC and provide a calculation, even if there is no tax due. See the next section for more details.