HMRC tax residency after moving to Argentina

A flight to Buenos Aires changes where you live, but HMRC still looks at the whole UK tax year to decide whether you are UK resident. That year runs from 6 April to 5 April. Argentina counts tax years from 1 January to 31 December and sets a separate start date for a foreign national's tax residence under article 116 of Income Tax Law 20.628. In the year you move, the two calendars may put the same income into two sets of records.

The UK Statutory Residence Test (SRT) determines UK status; Argentina's residence rules determine when worldwide income enters its system. UK-source income such as rent can remain reportable in the UK after departure, and Argentine-source earnings may be taxable in Argentina before worldwide-income taxation starts. The 1996 UK–Argentina Double Taxation Convention allocates taxing rights and relief by income type. It has been in force since 1 August 1997, with its multilateral instrument (MLI) text applying to withholding taxes in both countries from 1 January 2026.

Two tax years for one move

A British passport, UK bank account or Argentine DNI does not decide either country's tax residence. HMRC looks at UK days and connections within the tax year, while Argentina looks at the immigration-residence events described in article 116. A general 183-day slogan misses both tests.

That overlap is easiest to see in a departure-year household. Suppose two Brits arrive on 1 July 2026: one leaves a UK job on 30 June, the other lets a UK flat from August, and both receive temporary residence on 15 July. Their 2026/27 UK tax year includes eight UK days at Christmas and ten in March 2027. Eighteen days exceeds the fewer-than-16-days automatic overseas threshold for someone UK resident within the preceding three years, so the other SRT tests and any split-year case still matter. With uninterrupted temporary residence, their 12 months complete on 15 July 2027 and Argentine tax residence begins on 1 August 2027.

How UK days and ties add up

HMRC's RDR3 guidance explains the SRT under Schedule 45 to Finance Act 2013. The test considers automatic overseas rules first, then automatic UK rules, then sufficient ties. A UK day normally means being there at midnight, though deeming rules can add days. Travel dates, overnight stays and UK workdays over three hours are therefore useful records, especially when a January trip and an April trip fall in different UK tax years.

Someone UK resident in any of the previous three tax years meets an automatic overseas test with fewer than 16 UK days in the year. For someone not resident in any of those three years, the corresponding threshold is fewer than 46. Another overseas test for full-time work abroad requires fewer than 91 UK days and no more than 30 UK workdays, among other conditions. At 183 or more UK days, a person is automatically UK resident.

Between those clear cases, UK ties become decisive: a resident partner or minor child, a UK home you use, work in the UK on at least 40 days, or more than 90 UK days in either of the previous two tax years. Recent UK residents can also have a country tie if they spend the most midnights in the UK. For someone recently resident, two ties can bring UK residence at 91–120 UK days; at 121–182 days, one tie can do it. Split-year treatment in the departure year applies when a statutory case fits, rather than simply from the flight date.

When Argentine residence begins

For a foreign national, article 116 of Income Tax Law 20.628 sets two routes: obtaining permanent residence or completing 12 months' stay under temporary migration authorisations. Short absences allowed under the regulation do not break that continuity. Tax residence begins on the first day of the month following the month of the grant or the completed 12 months, hence the 1 August 2027 date in the July example. Loss of residence takes effect from the first day of the month after the relevant event, such as permanent residence abroad or 12 continuous months outside Argentina.

ARCA also distinguishes the rule for personal deductions: someone living in Argentina for more than six months of the fiscal year counts as resident for that purpose. The regulations provide a way to explain a stay that does not imply an intention of habitual permanence, with reasons submitted as ARCA requires. Neither point replaces the article 116 date for worldwide-income residence.

Where a UK bank, pension payer or property buyer needs proof for a treaty claim, ARCA issues a certificado de residencia fiscal online through the clave fiscal. The certificate is free; ARCA may request supporting papers within 15 days of the application. Records of the Migraciones decision and the effective residence date underpin that request.

What the treaty changes for income

The UK–Argentina treaty treats types of income differently. Article 18 assigns a private or workplace pension paid to someone resident in Argentina to taxation there alone. UK rent and gains on UK property can remain in both countries' reporting systems, with relief limited to tax charged on the same income. An ISA's UK tax exemption does not carry over into Argentina; a transfer between one's own accounts is capital rather than fresh income, so statements identifying transfers matter.

The UK State Pension can be paid into an Argentine account, but the UK does not pay annual increases to residents in Argentina. The amount stays frozen until a return to the UK; voluntary National Insurance contributions from abroad can fill gaps in a UK record. Treaty treatment of income still leaves the relevant returns to be filed.

The paperwork on each side

For a person leaving a UK job who does not file Self Assessment, HMRC's P85 service records the departure, P45 details and overseas address and can lead to a PAYE repayment. The online route is available after leaving; a postal route is available before departure. There is no fee. HMRC does not convert a repayment into foreign currency, so keeping a UK account until it arrives can be useful. P85 reports the move; it is the SRT that establishes residence.

Self Assessment filers instead use the SA109 residence pages to record UK days, ties and any split-year case. The online return is due on 31 January after the tax year ends. HMRC's basic online filing does not handle every supplementary page, so filing SA109 may require compatible software or a paper return.

UK landlords have another piece of administration. A letting agent or tenant normally deducts basic-rate tax under the Non-Resident Landlord Scheme; HMRC's NRL1 form, using a UTR and National Insurance number, requests gross rent payment. Approval usually starts on the first day of the quarter in which HMRC received the application. Gross payment changes withholding, while UK rent remains taxable and reportable; a sale of UK residential property triggers a UK property disposal return within 60 days of completion, even if no tax is due.

On the Argentine side, records for ganancias and bienes personales with ARCA include the Migraciones decision, CUIT, clave fiscal, pension statements, rental accounts, bank interest and evidence of UK tax paid. ARCA sets the return and payment dates for the calendar year being filed. For the household arriving in July 2026, the partner with UK rent would keep the rental accounts and could seek gross payment using NRL1; their Argentine 2027 records would show income either side of 1 August. Those dated records make the treaty's relief usable when the same income appears in both countries' filings.