SA108

The SA108 is a form that you have to fill in and attach to your main SA100 Self Assessment tax return if you need to declare and pay tax on capital gains from selling property, shares, crypto, or other assets for a profit.

You can download the SA108 from HMRC’s website – unless you submit your Self Assessment online, in which case you don’t need to worry about printing it, filling it, and mailing it to them.

Also, if you file your tax return online instead of via post, you get a longer deadline – January 31st of the following year (instead of October 31st).