Capital Gains Tax

6. Report and pay Capital Gains Tax

You can report any Capital Gains Tax you need to pay either:

  • straight away using the ‘real time’ Capital Gains Tax service
  • annually in a Self Assessment tax return

If you use the ‘real time’ service but need to send a tax return for another reason, you’ll have to report your gains again through Self Assessment.

If you’re a non-resident and you’ve sold a residential property in the UK, tell HM Revenue and Customs (HMRC) within 30 days, even if you have no tax to pay.

Before you report

You’ll need:

  • calculations for each capital gain or loss you report
  • information from your records about the costs and what you received (the ‘proceeds’) for each asset
  • any other relevant details, such as any reliefs you’re entitled to

Report your gain and pay straight away

You can use the ‘real time’ Capital Gains Tax service if you’re a UK resident. You’ll need a Government Gateway account - you can set one up from the sign-in page.

When you use the service you’ll need to upload PDF or JPG files showing how your capital gains and Capital Gains Tax were calculated.

When to report

You can use this service as soon as you’ve calculated your gains and the tax you owe. You don’t need to wait until the end of the tax year.

You must report by 31 January after the tax year when you had the gains.

The tax year runs from 6 April to 5 April the following year.

After you’ve reported your gains, HMRC will send you a letter or email giving you a payment reference number and telling you ways to pay.

Report in a Self Assessment tax return

Use Self Assessment to report your gain in the tax year after you disposed of assets.

If you don’t usually send a tax return, register for Self Assessment by 5 October following the tax year you disposed of your chargeable assets.

If you’re already registered but haven’t received a letter reminding you to fill in a return, contact HMRC by 5 October.

You must send your return by 31 January (31 October if you send paper forms).

You can get help with your tax return from an accountant or tax adviser.

After you’ve sent your tax return

HMRC will tell you how much you owe. The Capital Gains Tax rate you pay depends on your Income Tax rate.

You’ll need to pay your tax bill by the deadline.

You’ll have to pay a penalty if you send your tax return late, miss the payment deadline or send an inaccurate return.