Posted: Sun Feb 16, 2025 9:28am
You will have to declare the rental income for tax purposes in UK first. You then declare the rental income on your annual Spanish tax return and the tax you have paid in UK will be taken into account. As a resident, you can claim expenses and it will be taxed at the same rate as income starting from 19%.
If you sell the property in UK after becoming a tax resident in Spain, you will be liable to capital gains tax in UK as a second or buy to let home and you will also be liable to Spanish capital gains tax, again taking into account any tax you have paid in UK. Due to the escalation of house prices in UK this CGT could work out very expensive.