If you sell something valuable and make a profit this is called a Capital Gain. If the profit is over the amount HMRC allow, you will register for Self Assessment and file a tax return.
The annual exempt amount is £3,000 for the 2025/26 tax year.
If you sell a property that was never your main home, there are special tax rules. You will need to have enough information to work out what the taxable gain is (that is the amount you have got from the sale that needs to be taxed).
Find out more about reporting and paying Capital Gains Tax.
The records you need
You will need a record of:
- the gross proceeds received from the sale of capital assets
- the cost of the asset
- any improvement costs
- the costs of sale and purchase