Hi Susanna
The disposal of the overseas property, will need to be reported in the capital gains section of a self assessment tax return for the tax year in which the property was disposed of.
You will need to work out if you have made a gain on the disposal of the property.
There is a capital gains calculator a:
Tax when you sell your home: Private Residence Relief, which you can use to work out if there is a gain.
All figures must be in UK pounds sterling.
Under the terms of Self Assessment, we do not provide an official exchange rate and the onus is on the individual to use a just and reasonable exchange rate for each acquisition and disposal.
For your convenience, there are exchange rates at:
[ARCHIVED CONTENT] Exchange rates from HMRC in CSV and XML format and for older rates at:
[ARCHIVED CONTENT] HM Revenue & Customs: Exchange rates
You are free to use any of the supplied rates or one of your own choosing.
If you must pay capital gains tax on the disposal in Slovakia, you can claim up to 100% of the foreign tax paid, as a credit against UK capital gains.
Thank you