Citizenship, residency and tax residency

Three questions that need separate answers

Picture three documents on a kitchen table: a passport, a residence card and last year's tax return. Each answers a different question, and a different office decides it. Citizenship is a lasting legal tie to a country. Residence is the permission or right to live there. Tax residence is how a tax authority classifies a person for one tax year. A move can change one of them, two, or all three.

The OECD links the three in one sentence. Holding citizenship or a right to reside 'does not automatically mean that a person shall be considered a tax resident' there, or that tax residence 'is extinguished' in a former country. The same guidance adds that a person can be tax resident in more than one jurisdiction at once. ¹

Start a plan with three plain sentences: where the household wants a lasting tie, where it will live and work, and which tax systems will look at its year. Give each sentence an answer before comparing programs. MMT's global life planning pages carry the budget around those answers.

What is the difference between citizenship and residency?

Residence is permission; citizenship is membership. The UK draws the line clearly. GOV.UK describes indefinite leave to remain as how a person settles in the UK, and states that settlement gives the holder the right to live, work and study there for as long as they like, and to apply for benefits if eligible. Settlement is also a status the holder can use to apply for British citizenship, a separate application. ⁷

Read any residence approval as a set of permissions, conditions and dates. Five questions sort one route from another:

• Who it covers: the main applicant, a partner, children, and the rights each one gets.
• What it allows: study, a job with a local employer, self-employment, or remote work for an employer abroad.
• When it renews, and what evidence the renewal asks for.
• How time spent abroad counts toward keeping it.
• What ends it: a lost job, a sold investment or a changed family relationship.

Citizenship answers a different question: which country counts a person as its national. Its reach abroad comes from other countries' rules, as with EU citizenship, which carries the right to live and work across the EU. For a job that starts next spring, the result a household needs is permission to live and work in that one country. ⁸

Does a second residence automatically make me tax resident?

Tax residence follows a test, and each tax authority writes its own. In the UK, days, homes, work and family ties over the tax year decide it. In the US, a green card is enough on its own: under the IRS green card test, a lawful permanent resident of the United States at any time during the calendar year is a US resident for federal tax purposes. ^{6, 12}

Banks ask as well. Under the OECD's Common Reporting Standard, financial institutions must ensure account holders disclose all of their tax residences on a self-certification form. ¹

The UK sets out its test on GOV.UK, which points to HMRC's Statutory Residence Test. A person is UK resident for tax when they meet one or more of the automatic UK tests or the sufficient ties test, and fall outside all of the automatic overseas tests. The count runs over the UK tax year, from 6 April to 5 April the following year. ⁶

The three automatic UK tests, in GOV.UK's terms

• 183 or more days spent in the UK in the tax year. ⁶
• An only home in the UK for 91 days or more in a row, visited or stayed in for at least 30 days of the tax year. ⁶
• Full-time work in the UK for any period of 365 days, with at least one day of that period in the tax year being checked. ⁶

A person can also be resident under the sufficient ties test, which combines a number of days in the UK with 'additional ties to the UK, like work or family'. ⁶

GOV.UK's overseas tests point the other way. A person is usually non-resident after fewer than 16 days in the UK, or fewer than 46 days for someone who has not been UK resident for the 3 previous tax years. Full-time work abroad, averaging at least 35 hours a week, with fewer than 91 days in the UK and no more than 30 of them spent working, has the same result. ⁶

The year of a move has its own rule. GOV.UK explains that when a person moves in or out of the UK, the tax year is usually split into a non-resident part and a resident part, called split-year treatment. For someone who returns, the stay abroad must last at least a full tax year, and other conditions apply. ⁶

How work permission and residence rights interact

Entry, residence and work are three separate permissions. The UK's Standard Visitor rules show where a visit ends. GOV.UK places paid or unpaid work for a UK company, or work as a self-employed person, outside a visit, apart from a permitted paid engagement or event. The same rules bar living in the UK for long periods through frequent or successive visits, and making the UK a main home. ¹³

Plan a long stay as a residence question from the start. Check each person in the household separately, because a job offer can settle one adult's permission and leave a partner's work plans open. Describe the activity exactly: two client meetings, a contract with a local employer, running a consultancy and remote work for an overseas employer are four different cases. MMT's guide to tourist entry vs remote-work permission sets them apart.

EU citizens move on different terms. Your Europe, the EU's official guide, states that an EU citizen has the right to move to any EU country to live, work, study, look for a job or retire. A stay of up to 3 months in another EU country runs without registering as a resident, and some countries ask people to report their presence. A stay longer than 3 months can require registering residence. ⁸

Remote work adds the employer's question. The OECD's June 2026 guidance sets a general rule: a person working from their home in another country for less than half of their total working time 'would not, on its own, result' in a taxable place of business there. Above that share, a commercial reason for the business to operate from that country matters to the analysis. ¹⁴

The routes themselves sit in MMT's residency routes section, and remote-work visas compared sets one applicant against several programs side by side.

Does the 183-day rule decide tax residence?

183 appears in both the UK and US tests, and it does a different job in each. In the UK, 183 days in the tax year is one of three automatic UK tests, beside an only home and full-time work. In the US, 183 is a weighted total across three calendar years, and the current year needs at least 31 days of its own. ^{6, 4}

The US substantial presence test in five steps

The IRS considers a person a US resident for tax purposes for a calendar year when they meet this test. The steps below carry one worked example: 150 days in the United States this year, 90 last year and 60 the year before. ⁴

1. 01

   Count this year's days

   Count each day of physical presence in the United States, at any time during the day. The IRS leaves out days such as regular commutes to work from a home in Canada or Mexico, stays of less than 24 hours in transit between two places outside the country, days a medical condition that develops in the country prevents leaving, and days as an 'exempt individual', an IRS category that does not mean exempt from US tax. Leaving out medical or exempt-individual days takes Form 8843, filed on time. Example: 150 days. ⁴

2. 02

   Check the 31-day floor

   The current year needs at least 31 days. Example: 150 days clears the floor, so the count goes on. ⁴

3. 03

   Add one-third of last year's days

   Example: 90 days last year count as 90 divided by 3, which is 30. ⁴

4. 04

   Add one-sixth of the days from two years back

   Example: 60 days two years ago count as 60 divided by 6, which is 10. ⁴

5. 05

   Compare the total with 183

   Example: 150 + 30 + 10 = 190 weighted days. That meets the test, although the current year holds only 150 days. ⁴

A year under 183 days has one more check. The IRS's closer connection exception keeps a person who meets the test from being treated as a US resident for that year when all four of its conditions hold, and the claim is made on Form 8840, filed on time. The example's 150 days meet the first condition; the other three turn on the person's home, ties and immigration steps. ⁵

• Fewer than 183 days in the United States during the year. ⁵
• A tax home in one foreign country, kept for the entire year. ⁵
• A closer connection during the year to that country than to the United States. ⁵
• No steps taken toward lawful permanent resident status (a green card), and no application for it pending. ⁵

A calendar that keeps every year under 183 days can still meet the US test, as the example shows. In the UK, the only-home test looks at a home held for 91 days in a row and used on at least 30 days of the tax year. Count by each country's own year: 6 April to 5 April in the UK, the calendar year in the US. ^{6, 4}

What happens when two countries both claim you as resident?

Two tax systems can both say yes. The IRS calls a person who is a resident of both the United States and another country 'under each country's tax laws' a dual resident taxpayer. That person can still claim treaty benefits, and the treaty between the two countries must contain a provision that resolves conflicting claims of residence. ¹⁵

The IRS adds a limit for US citizens: with certain exceptions, tax treaties do not reduce their US taxes, and they remain subject to US income tax on their worldwide income. ¹⁵

The claim has its own paperwork. A dual resident who claims treaty benefits as a resident of the other country files Form 1040-NR with Form 8833 attached, according to the IRS. US states add a layer. Many tax their residents' income, and in the IRS's words, 'some states honor the provisions of U.S. tax treaties and some states do not'. The IRS points to each state's tax authority for its answer. ¹⁵

Put these questions to the adviser when two countries claim the same person:

• Which treaty provision resolves the conflict, and what conditions it sets.
• Which claim or disclosure forms each country requires, and by what date.
• How state, provincial or local taxes treat the same income.
• What the conclusion changes for each tax year, and what it leaves in place.
• Which facts the conclusion assumes, written down with the tax year attached.

How to prepare an evidence file before relocating

A move is a set of dated facts, and the file holds them. Advisers in the old and new countries should work from the same timeline, so both see the same departure and the same arrival. GOV.UK names the changes that call for a fresh look at UK residence: more or less time in the UK, buying or selling a UK home, and a change of job. ⁶

• A travel record by tax year: 6 April to 5 April for the UK, the calendar year for the US test. ^{6, 4}
• Home dates: when each home became available, when it stopped, and who lived there.
• Working time by country as a share of the total, since the OECD's general rule on an employer's taxable presence turns on half of working time. ¹⁴
• Where each adult filed personal income tax returns last year, one of the follow-up questions the OECD lists for a bank checking a tax-residence claim. ¹⁶
• Each person's nationalities and immigration documents, with expiry and renewal dates.
• Income by type: salary, self-employment, investments and pensions, each with its records.

Income type changes the US relief. For self-employment income, the excluded amount reduces regular income tax and leaves self-employment tax unchanged. To claim the foreign earned income exclusion, the IRS requires foreign earned income, a tax home in a foreign country, and one of these: ¹⁷

• A US citizen who is a bona fide resident of a foreign country for an uninterrupted period that includes an entire tax year. ¹⁷
• A US resident alien who is a citizen or national of a country with a US income tax treaty in effect, and a bona fide resident of a foreign country for an uninterrupted period that includes an entire tax year. ¹⁷
• A US citizen or US resident alien physically present in a foreign country for at least 330 full days during any 12 consecutive months. ¹⁷

Banks test the story too. The OECD bars a financial institution from relying on a self-certification it knows, or has reason to know, is incorrect or unreliable, and that includes a claim of tax residence in a high-risk investment-migration jurisdiction alone. Give nationality, home address, mailing address and tax residence as four separate answers, keep a dated copy, and update the bank when the facts change. ¹⁶

Compare the outcome you actually need before choosing a route

Price the result first, then the route. The table sets three citizenship programs from MMT's country pages beside one residence visa, each total built from the published fee lines on 13 September 2026. ^{3, 18, 9, 2}

What each total buys, and what it leaves for later:

• Nauru: $102,700 pays one applicant's contribution and fees for a citizenship application. An agent's advisory fee comes on top. ³
• Antigua and Barbuda: $266,700 covers a four-person household's fund contribution, processing, due diligence and passports. The licensed agent's fee sits outside the total. ^{18, 20}
• St Kitts and Nevis: $267,500 covers the contribution and due diligence for a couple with two children under 16, or $302,500 through the Public Benefit Option with post-approval fees. The unit's December 2025 update says the program will begin moving away from contribution-based routes during 2026. ^{9, 10, 24}
• Spain's remote-work visa: $326.85 covers one US citizen's NIE and visa fees, the visa center's service and courier charges and a translation. It buys permission to live in Spain on the route's terms, and leaves citizenship and tax residence as separate questions. ^{2, 21, 22, 23, 19}

Banks read these programs through the OECD's lens. Its tax-residency portal marks Antigua and Barbuda, Dominica, Grenada, Saint Lucia, St Kitts and Nevis and Vanuatu as offering investment schemes that present 'a high risk of being misused for circumventing CRS reporting'. Expect questions about where the household actually lives and files. ¹

Match the route to the household's goal. Start from the goal that fits:

• A job or a school place in one country next year: start with that country's residence permissions, because work rights come from the destination's own rules.
• A fallback home for later, with a move years away: compare how durable each right is, what it costs to keep, and which family members it covers. Leave tax savings out of the case until a move is real.
• Time split across several countries: map the whole year's schedule against each country's tax test before paying for any route, then test the plan against a few extra weeks at home.

MMT's citizenship by investment countries pages set out each program's rules, and the real cost of citizenship by investment adds what a status costs to keep. The Argentina page tracks where that country's investment citizenship stands today.