tax on Spanish holiday home sale

In selling a holiday home in Spain, being uk resident I will declare the sale on a self assessment return at the end of the tax year. A compulsory tax deduction of 3% of gross sale price was deducted and has been paid to Spanish authorities: can I include this as part of the costs of sale, or where else do I declare it in order not to be taxed twice?

Hi zontes,
In the foreign section for dividends of SA106 (Foreign Tax year 6 April 2022 to 5 April 2023 (2022–23) and Foreign notes Tax year 6 April 2022 to 5 April 2023 (2022–23)) and the online equivale, there is a box for foreign tax paid.  
You can claim a foreign tax credit of up to 100% of the foreign tax paid, so that you are not paying the same tax twice.
Thank you