Moving to Portugal from the UK: Your 2026 Tax Transition Checklist

You’ve decided to move from the UK to Portugal. The Brexit paperwork is sorted, the D7 or D8 visa is approved (or you’re an EU citizen and skipped that bit), and somewhere on your to-do list is “figure out the tax thing.” This guide is that bit.

The headline question - “do I pay UK tax or Portuguese tax on X?” - is answered by the PT/UK Convention for the Avoidance of Double Taxation (CDT). Different income types live under different articles of the Convention, and the answer to which country taxes what is often “both, with a credit” rather than one or the other.

The bigger trap is timing. The day you stop being a UK tax resident and start being a Portuguese tax resident is not the day you move - it depends on day-counts, ties, and split-year provisions. Get the timing wrong and you can be tax-resident in both countries for the same income (and credit relief gets messy) or in neither (which sounds great until HMRC or AT comes asking).

The PT/UK Convention - what it actually does

The PT/UK CDT is a bilateral treaty that allocates taxing rights between Portugal and the United Kingdom for residents of either country. It doesn’t reduce tax - it just prevents the same income being fully taxed twice. The mechanism, almost always: one country has the primary right to tax, the other gives a credit for tax paid in the first.

The articles that come up most often for UK arrivals:

Article	Income type	Plain-English summary
Art. 14	Employment income	Taxable where the work is physically performed. Move to PT → PT taxes from day one of PT residence.
Art. 17	Pensions (non-government)	Taxable only in the resident country. Move to PT → PT taxes your UK occupational/SIPP/state pension.
Art. 18	Government service pensions	Taxable only by the paying state (usually UK). PT doesn’t tax these.
Art. 6	Real estate income	Taxable where the property sits. UK rental → UK can tax. PT also taxes (residence) and gives credit.
Art. 13	Capital gains on property	Same as Art. 6 - country where property sits has taxing rights; PT taxes as resident with credit.
Art. 10	Dividends	Source country can withhold (capped at 15% for PT residents). PT taxes at 28% with credit for the 15% withheld.
Art. 11	Interest	Source country can withhold (capped at 10% under the Convention). PT taxes at 28% with credit.

The exact article numbering matches the 1968 Convention as amended; HMRC and AT both reference these. When in doubt, the full Convention text is on AT’s site under Convenções para Evitar a Dupla Tributação.

When does PT residence actually start?

This is the question most UK arrivals get wrong. Under Portuguese tax law (CIRS art. 16), you’re a PT tax resident in any calendar year where:

• You spend more than 183 days in Portugal during the year, OR
• You spend ≤183 days but have habitual residence in PT (e.g., a permanent home available to you as of 31 December)

Under UK rules, the Statutory Residence Test (SRT) determines if you’re UK-resident for any given tax year (UK tax year = 6 April to 5 April). The SRT considers day-counts plus “ties” (family, accommodation, work, 90-day previous-year tie, country tie).

The UK has a split-year treatment that lets you treat the UK tax year as split between a UK-resident part and a non-UK-resident part if specific conditions are met (Cases 1-8 of HMRC’s RDR3). Portugal does not have a formal “split year” - you’re either a PT resident for the calendar year or you’re not - but the practical effect is similar through Convention tie-break.

Pragmatic guidance: pick a clean arrival date, document it (flight tickets, lease signed, utility connections), and treat that as your PT residence start. File your last UK return claiming split-year treatment for the move year, and your first PT IRS for the calendar year of arrival declaring only PT-period income.

Path A - UK employment income (still working for a UK employer)

If you keep working remotely for a UK employer after moving to PT, the picture is:

Path B - UK pensions (the big one for retirees)

This is where most UK retirees moving to PT lose money to avoidable mistakes. Three pension types, three different treatments:

B1. State Pension (UK basic + new state pension)

Under Art. 17 of the PT/UK Convention, your UK State Pension is taxable only in Portugal once you’re PT-resident. To stop UK tax being deducted at source, file form DT-Individual UK/Portugal with HMRC - they then pay you gross. You declare the gross amount in PT on Quadro 9 of Anexo J (Cat H - foreign pensions) at progressive rates (or 10% flat if you have NHR).

The DPNI (international service that pays the State Pension to overseas residents) won’t apply the DT form automatically - you have to send it.

B2. Occupational / personal pension (employer DB, SIPP, etc.)

Same Convention rule (Art. 17): taxable only in PT. Same DT-Individual form to stop UK tax at source.

Where this gets interesting: many UK pensions are administered by providers (Aviva, Aegon, AJ Bell, etc.) who reflexively apply UK PAYE unless told otherwise. You may need to chase your provider for several months to get them to pay gross.

B3. Government service pension (civil service, NHS, armed forces, teachers)

Different rule under Art. 18: taxable only in the UK. PT doesn’t tax these. If your pension is one of these, the move doesn’t change anything UK-tax-wise.

But there’s a quirk: the pension still counts as part of your worldwide income for some PT tax computations (e.g., the marginal rate that applies to other PT-taxable income). You declare it on Anexo J as exempt-with-progression and PT uses it to set your bracket but doesn’t tax it.

Path C - UK property (still own it after moving)

If you keep your UK house and rent it out, or sell it post-move, two articles apply:

C1. Rental income

Art. 6 of the Convention: UK has the right to tax rental income on UK property (it’s UK-source). You file a UK Non-Resident Landlord (NRL) Self Assessment each year - HMRC’s Non-Resident Landlord Scheme either has your tenant/agent withhold 20% basic-rate tax or, if you’ve applied to receive rent gross (form NRL1), no withholding.

Portugal also taxes the same rental as a resident - on Quadro 7 of Anexo J. You claim a foreign-tax credit for the UK tax paid (up to what PT would have charged on the same income).

Net effect: you typically end up paying the higher of the two countries’ tax rates on the net rental, not both.

C2. Selling the UK property after moving to PT

Art. 13(1): gains on immovable property can be taxed by the country where the property is located (UK). UK Capital Gains Tax on residential property for non-residents is 18% / 24% (basic / higher rate, 2026 rates).

Portugal also taxes the gain as a resident. It goes on Quadro 8 of Anexo J. PT residents get a 50% reduction on capital gains from real estate (CIRS art. 43) - then the remaining 50% is taxed at progressive brackets via englobamento (or 28% flat if elected).

You credit UK CGT paid against the PT bill, capped at what PT would have charged.

Path D - UK investments (ISAs, GIAs, dividends)

D1. ISAs are not tax-shielded in Portugal

This is the surprise that catches almost every UK arrival. ISA wrappers don’t exist in Portuguese tax law. AT looks through the wrapper and taxes the underlying interest, dividends, and capital gains as if you held them in a normal account.

Cash ISA: interest taxable in PT at 28% flat (or progressive via englobamento) - on Quadro 6 of Anexo J.

Stocks & Shares ISA: dividends taxable in PT at 28% flat - on Quadro 6 of Anexo J. Capital gains on sales are taxable on Quadro 8 of Anexo J (28% flat or progressive). Foreign-tax credit for any UK tax paid at source (rare on ISAs since they’re UK-tax-free).

Lifetime ISA / Innovative Finance ISA: same look-through treatment.

Practical implication: holding ISAs after becoming PT-resident often makes them less tax-efficient than just keeping the assets in a regular UK General Investment Account, since you lose the UK shelter and the PT treatment is the same either way. Some UK arrivals choose to liquidate ISAs before moving (no PT tax on pre-residence gains) and re-invest in a PT-friendly structure.

D2. UK dividends and interest

Covered above under the Convention table: source-country withholding capped at 15% (dividends) or 10% (interest), PT taxes at 28% with credit. Declare on Anexo J Quadro 6.

For more detail on the mechanics, see the Anexo J step-by-step guide.

Path E - UK RSUs and stock options that vest after you move

Common for tech workers moving from London. RSUs granted by a UK employer, vesting after you’ve become a PT resident.

Treatment is apportionment by workdays:

• The portion of the RSU “earned” during UK workdays (typically the period between grant and the move) is UK-taxable as employment income.
• The portion earned during PT workdays (between move date and vesting date) is PT-taxable.

The split is usually pro-rata by calendar days, but if there’s a different cliff/grading schedule it can get more granular.

PT taxes the PT-portion as Cat A salary on Anexo J Quadro 4 if paid by a foreign employer, or via the normal Cat A flow (Anexo A) if the UK employer has set up a PT payroll. UK taxes its portion through PAYE or via Self Assessment if PAYE doesn’t catch it.

NHR / IFICI / standard - which regime fits a UK arrival?

Year you became PT-resident	Eligible regimes
Before 2024	NHR (if registered in time) + standard. NHR is best for high foreign passive income (pensions, dividends).
2024 onwards	Standard + IFICI (if your work qualifies). NHR is closed to new applicants.

For a typical UK retiree moving in 2026: standard regime, full stop. NHR is not available; IFICI doesn’t fit retirees (it requires qualifying scientific/innovation activity).

For a UK software engineer moving in 2026: standard regime by default; check whether your specific role qualifies for IFICI (most general software work doesn’t; R&D and academic-adjacent roles do). The eligibility checker takes a job title.

Standard regime isn’t a disaster - the 2026 brackets start at 12.5% and the family quotient can be very competitive for sole-earner couples.

For a head-to-head with UK tax rates, see Portugal vs UK Tax for Expats - which now also covers the UK FIG regime that replaced non-dom.

When to file your own pedido de informação vinculativa

A pedido de informação vinculativa (PIV) is a binding ruling from AT on how a specific situation in your name will be taxed. It’s a written question to AT with all your relevant facts; their answer is binding on AT, for you specifically, for the period addressed.

Worth filing one if:

• You’re taking a large UK pension lump sum and want PT’s treatment locked in before you take it
• You’re selling a UK property with unusual ownership history (joint with a family member, prior business use, etc.)
• You’re carrying forward UK losses you’d like to use against PT gains
• You have a non-standard situation the standard guides don’t cover

Cost: free to file (online via Portal das Finanças). Time: AT can take 4-6 months to respond. Filing one only protects you - not your spouse, not your kids, not the next person with the same situation.

Common mistakes UK arrivals make

Taking the 25% pension lump sum after moving. Covered above. Single most expensive avoidable mistake.

Assuming ISA is tax-free everywhere. It isn’t outside the UK. Plan around this before becoming PT-resident.

Filing only one country’s return in the move year. You need to file the UK return (claiming split-year treatment) AND the PT return (for the PT portion of the year). Skipping one creates problems years later when the other country audits.

Not telling your UK pension provider you’ve moved. They keep applying UK PAYE; you over-pay UK tax for years until you sort it.

Selling the UK home too late. Each year you remain non-UK-resident, more of any gain becomes UK-CGT-able for non-residents (post-April 2015 rules). PT side, you get the 50% real estate gain reduction, but the absolute number you owe usually rises with the gain itself.

Treating the PT/UK Convention as automatic. It isn’t - you have to claim treaty benefits on the right forms (DT-Individual to HMRC, foreign-tax credit on Anexo J Quadro 10). Without the paperwork, you can end up double-taxed by default.

When to hire a cross-border specialist

DIY is doable for simple cases: salary only, one country of source, no property, no large pension. The Modelo 3 + Anexo J flow is well-trodden.

Get a specialist for:

• Any pension above £100k in the move year
• UK property being sold during the transition
• RSU vesting that spans the move
• Trust or company ownership structures
• Year you become PT-resident if you also have US/CA/other income (treaty stacking gets hairy)

Costs: roughly €600-€2,500 for a clean transition-year filing, less in normal years afterward. UK side, expect £400-£1,500 for a transition return. Total: less than your first quarter of mistakes on the items above.

Sources

• PT/UK Convention text on AT - search Reino Unido under Convenções para Evitar a Dupla Tributação
• HMRC RDR3 - Statutory Residence Test
• HMRC form DT-Individual UK/Portugal
• Portal das Finanças - Anexo J instructions
• CIRS art. 16 - tax residency
• CIRS art. 81 - foreign-tax credit
• Portugal vs UK Tax for Expats - the decision guide if you haven’t moved yet
• Foreign-Source Income on Anexo J - mechanics of declaring foreign income
• IFICI Portugal application guide - if your work might qualify

This is a heads-up guide, not a substitute for personalised advice. Your specific situation will have details that change the answer - especially around pensions and property timing. If you spot something out of date, email hello@taxclara.pt and we’ll fix it.