If you haven't received a tax return and have Capital Gains Tax to pay, you need to contact HM Revenue & Customs (HMRC). If you already complete a Self Assessment tax return, you may need some additional Capital Gains Tax pages.
On this page:
Before you do anything else, you need to work out if you have Capital Gains Tax to pay (see the links below if you need help with this).
If you do have Capital Gains Tax to pay, you need to tell HMRC - you may face a penalty if you don't tell them in time. The way you tell HMRC differs depending on whether or not you already complete a Self Assessment tax return.
Is your asset liable to Capital Gains Tax?
Working out your capital gain or loss - the basics
If you're already a Self Assessment taxpayer, you should automatically receive a tax return - or a letter telling you to file online. You'll usually need to complete some additional Capital Gains Tax pages to tell HMRC about your capital gains.
If you haven't received a tax return (or a letter telling you to file online) and you have Capital Gains Tax to pay, you should get in touch with HMRC before 5 October. They'll send you the forms you need.
If you don't normally complete a tax return and have Capital Gains Tax to pay, you'll need to register for Self Assessment before you can send in a tax return. Make sure you do this before 5 October. You can use the link below to download a registration form.
Download a registration form for Self Assessment (PDF 44K)
Find out more about Self Assessment
When you're filling in your Self Assessment tax return, you won't always have to complete the Capital Gains Tax pages.
You don't need to report gains on assets that aren't liable to Capital Gains Tax - for example gains on private cars, shares in ISAs and, in most cases, your main home.
You also don't need to report your gains if all of the following conditions are met:
Find out if your asset's liable to Capital Gains Tax
More about Capital Gains Tax rates and tax-free allowances
Download a simple guide to residence and domicile (PDF 21K)
For most trustees similar rules to those above apply, but the amounts are slightly different. Trustees don't need to complete the additional Capital Gains Tax pages of their 2010-11 tax return if all of the following apply:
More about Capital Gains Tax rates and tax-free allowances
If you haven't filed online before, you'll need to set yourself up to use HMRC Online Services. Make sure you have the following information to hand:
You'll find your Unique Taxpayer Reference (UTR) on correspondence from HMRC, for example on your welcome letter if you're new to Self Assessment. If you can't find it you can contact your Tax Office and they'll send it in the post to your home address.
Read more about using Self Assessment online
If you send your tax return online, it must reach HMRC by midnight on 31 January after the end of the tax year.
The deadline is only later than 31 January if you received the notice to file your tax return after 31 October. You'll then have three months from the date you receive the notice to send your return online.
Log in to HMRC Online Services
Find out about tax return and payment deadlines and penalties
If you completed a paper tax return last year - you’ll normally receive a tax return in April just after the end of the tax year. But you won't automatically get the additional Capital Gains Tax pages you'll need. You can download them using the links below.
As an individual, you'll use:
Trustees will use:
Get form SA108 Capital Gains Summary and notes
Get form SA905 Trust and Estate Capital Gains and notes
Find out more about reporting capital gains on a trust
If you send in a paper tax return, it must reach HMRC by midnight
on 31 October after the end of the tax year.
The deadline for paper tax returns is only later than 31 October
if:
When you send in your tax return, you’ll need to attach calculations that show how you've worked out your capital gains. You should keep a copy of these calculations.
You should also keep other records - such as records showing your costs when you buy, sell or improve an asset.
See what records to use and keep for Capital Gains Tax
You must also tell HMRC about losses if you want to deduct them from your gains. There’s a specific way to do this, as well as time limits for reporting and using losses.
Find out how to report and use losses
Don’t miss these dates or you may have to pay a penalty, interest or a surcharge on top of the tax you owe.
Find out more about Self Assessment deadlines and penalties
Is your asset liable to Capital Gains Tax?
