Since Brexit, British citizens move to Portugal under the rules for non-EU nationals, usually with a residence visa. The tax side needs some planning: the UK tax year runs from April to April, Portugal’s follows the calendar year, and each country has its own residence rules.
Leaving the UK
Tell HMRC you are leaving, usually with form P85, so your UK tax position is settled and any refund is processed. Keep records of your departure date and your UK income and assets: you will need them to show when you became resident in Portugal.
Pensions and UK income
Under the UK–Portugal double taxation convention, the UK State Pension and most private pensions are taxed in Portugal once you are resident. Government service pensions (civil service, armed forces or police, for example) generally remain taxable only in the UK. UK rental income can be taxed in both countries, with the UK tax credited in Portugal.
Arriving in Portugal
You will need a NIF (with a tax representative until you live here), registration with Social Security and, once resident, your address updated with the Tax Authority. Portugal lets you split the year of arrival, so you are only taxed as a resident from the day you move. If you work in a qualifying profession, look at IFICI before you apply.