Hi,
The gain should be reported. How to do this depends on your circumstances:
1. If you are already within Self Assessment you should report the gain in your Self Assessment return.
2. If you are not within Self Assessment but the gain (together with your other savings and investment income) exceeds £10,000, you should register for Self Assessment and report the gain in your Self Assessment return.
See the following guidance on how to register.
When reporting the gain in your return, use supplementary pages
SA106
Include the details of the gain under ‘Other overseas income and gains’
3. If you are not within Self Assessment and the gain (together with your other savings and investment income) does not exceed £10,000, you should report it by either:
Contacting
Self Assessment: general enquiries
Sending a copy of the chargeable event certificate to Self Assessment, HM Revenue and Customs, BX9 1AS.
Please include your National Insurance number.
Thank you.