Yes. As at 2026/27, each country decides residence under its own domestic rules, so you may meet the UK Statutory Residence Test and another country's test in the same year. Where there is a double tax treaty between the two countries, its tie-breaker rules generally decide which country you are treated as resident in for treaty purposes. Without a treaty, both countries may tax you, with any relief depending on each country's domestic rules.

How dual residence happens

There is no single international definition of tax residence. Some examples:

  • UK: the Statutory Residence Test looks at the tax year from 6 April to 5 April. You are automatically UK resident if you spend 183 days or more in the UK, and may also be resident through the automatic UK tests (such as having a UK home) or the sufficient ties test, which combines your day count with ties such as family, accommodation and work.
  • UAE: under Cabinet Decision No. 85 of 2022 you are generally tax resident if you spend 183 days or more in the UAE in a 12-month period, or 90 days with qualifying nationality or a residence permit plus a permanent home or work there, or if your usual residence and centre of financial and personal interests are in the UAE.
  • Portugal: you are generally resident if you spend more than 183 days in Portugal in any 12-month period starting or ending in the year, or if you have a home there in circumstances suggesting you intend to keep it as your habitual residence.
  • Spain: the Agencia Tributaria looks at the calendar year. You are generally resident if you spend more than 183 days in Spain (sporadic absences count unless you prove tax residence elsewhere), or if your main centre of economic interests is there. There is a rebuttable presumption of residence where your spouse and dependent minor children live in Spain.

Because the periods and tests differ, overlaps are common in the year you move, and for people who keep homes in two places.

How treaty tie-breakers decide

Most UK treaties, including those with the UAE, Spain and Portugal, use a similar order of tests. HMRC's international manual summarises them:

  1. Permanent home. Where you have a permanent home available to you. If both, move on.
  2. Centre of vital interests. Where your personal and economic relations are closer.
  3. Habitual abode. Where you habitually live, judged by time and pattern.
  4. Nationality. If still unresolved.
  5. Mutual agreement. The two tax authorities settle it.

The tie-breaker does not change your UK residence status under the Statutory Residence Test. It decides which country gets priority under the treaty for each type of income. A person who is UK resident but treaty resident elsewhere is often called "treaty non-resident", and HMRC says they still have UK filing obligations as a UK resident.

Split years can help

In the year you leave or arrive, the UK may split the tax year into a UK part and an overseas part if you meet one of the split year cases. Portugal also treats residence as starting or ending part way through a year in some cases. These rules may remove much of the overlap. Our guide to moving from the UK and the Statutory Residence Test explains how split years work.

Illustrative example

Illustrative example only, not a real client.

Helen moves from London to Lisbon on 1 August 2026 and sells her UK home. She is in the UK every day from 6 April to 31 July 2026, which is 117 days, and returns for 10 days at Christmas, giving 127 UK days in 2026/27. Assumptions: UK resident in earlier years, family and recent work ties in the UK, no other UK home.

  • UK: 127 days is below the 183 day automatic UK test and above the automatic overseas thresholds, so she may be UK resident for the year, for example under the sufficient ties test. If so, she may qualify for split year treatment from 1 August, depending on which split year case she meets.
  • Portugal: she has a home in Lisbon from August, so Portugal may treat her as resident from her arrival.

Without split year treatment, she could be resident in both for the UK tax year, and the UK-Portugal treaty tie-breaker would look first at where she has a permanent home. With split year treatment, most of the overlap may fall away.

Common mistakes

  • Assuming leaving the UK automatically ends UK residence for the whole tax year.
  • Not checking the new country's own test, which may start residence from the day you arrive.
  • Treating a treaty tie-breaker as if it makes you UK non-resident for every purpose.
  • Keeping a home available in both countries without considering the permanent home test.

Talk it through

Getting residence clear in the year you move often has the biggest impact on pensions, investments and gains. A regulated financial adviser can help. Get in touch for a free introduction.

Sources and further reading

Last reviewed: October 2026. Tax year: 2026/27 (UK); 2026 (Portugal, Spain, UAE). Jurisdictions covered: UK, UAE, Portugal, Spain. Rates, legislation and guidance change, so recheck before relying on this. Rules can differ between England and Wales, Scotland and Northern Ireland; tax residence is fact-specific; treaty outcomes depend on residence, domicile or nationality provisions; examples are simplified and omit reliefs, costs, exchange rates and anti-avoidance rules. This is general information, not financial, tax or legal advice. Take advice in the relevant country before acting.