For people relocating from the United Kingdom to the United States

Moving to the US From The United Kingdom: Your First US Tax Year

Moving from the United Kingdom to the US changes your tax position in stages. This guide covers when US residency starts, the dual-status first year, the treaty tie-breaker and what happens to accounts you keep in the United Kingdom.

Substantial presenceGreen card testDual-status yearTie-breakerSocial security

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Quick answer

When does someone moving from the United Kingdom start paying US tax on worldwide income?

From the residency starting date: the first day in the US in a year you meet the substantial presence test, or the first day as a permanent resident under the green card test (IRS Pub 519). Before that you are a nonresident, so the first year is usually dual-status. If you are also resident in the United Kingdom, Article 4 (Residence) of the treaty decides which country you are resident in for treaty purposes.

Prepared by Illuminous Accounting · Sources checked November 11, 2026

At a glance

When you become US resident: Green card test or substantial presence test (Code section 7701(b))
First year: Usually dual-status: nonresident, then resident
Treaty tie-breaker: Article 4 (Residence)
Social security agreement: Yes, since January 1, 1985
Accounts in the United Kingdom: FBAR, Form 8938 and PFIC rules can apply once resident

The residency starting date

Expect your first year to have two halves. Income from the United Kingdom before you became resident is generally outside US tax unless it is US-source; income after the residency starting date is taxed worldwide (IRS Pub 519). The starting date is your first day in the US in that year under the substantial presence test, or your first day as a permanent resident under the green card test. People who arrive near year end may be able to opt in early under the first-year choice. Getting the date right decides which UK salary, bonuses and investment income the IRS sees.

The two US residency tests

Test	You are a US tax resident if	Source
Green card	You hold lawful permanent resident status at any time during the calendar year	Pub 519
Substantial presence	31 days this year and 183 weighted days over 3 years (all of this year, one third of last year, one sixth of the year before)	Pub 519

These come from Code section 7701(b). A work visa, a student visa or a move for family from the United Kingdom all go through the same two tests; some visa holders can exclude days. Try the calculator.

Resident in both countries: the US-United Kingdom treaty tie-breaker

During the move you can be resident in both the United Kingdom and the US under each country's law. Article 4 (Residence) of the treaty has the tie-breaker for someone resident in both countries: it looks first at where you have a permanent home available, then at the further tests the article lists, in the order it sets them. If the treaty makes you a resident of the United Kingdom, you can be taxed as a nonresident of the US for the treaty's purposes, but that position must be disclosed on Form 8833 under Treas. Reg. section 301.7701(b)-7 (IRS Form 8833).

Green card holders should be careful: a long-term resident who claims treaty residence abroad this way may be treated as having expatriated under section 877A (IRS).

Your accounts back home

Once you are a US resident, bank, pension and investment accounts you keep in the United Kingdom can bring the FBAR and Form 8938, and funds held there are often treated as PFICs (Form 8621, IRS). See FBAR and FATCA and Form 8938 for who files and the thresholds.

Sources for moving from the United Kingdom

Treaty

The IRS lists the 2001 income tax treaty, signed July 24, 2001, amended by a protocol and exchange of notes listed for 2001. General effective date (IRS Table 3): treaty Jan. 1, 2004 (IRS treaty documents for United Kingdom; treaty text; IRS Table 3).
Residence and tie-breaker: Article 4 (Residence).
Saving clause: Article 1 (General Scope).
Article 17 (Pensions, Social Security, Annuities, Alimony, and Child Support), pensions.
Article 24 (Relief from Double Taxation), relief from double taxation.
Article 14 (Income from Employment), employment income.

US law

US residency tests and starting dates: Code section 7701(b) (IRS Pub 519).
Treaty residence for dual residents: Treas. Reg. section 301.7701(b)-7, Form 8833 and section 6114; long-term residents: section 877A (IRS Form 8833).
Social security agreements: SSA list.

The rules of the United Kingdom on leaving the country also apply; check them with a local adviser.

How we help

We start with your travel dates and your last UK tax year, work out the residency starting date and whether the treaty tie-breaker applies, then prepare the US return and any Form 8833. Gurleen Kaur, CPA (BC and Washington), signs. You get a written quote first.

Moving from other countries

All countries: moving to the US, by country. From Canada: moving from Canada to the US.

Common questions

Does my visa decide my US tax residence after moving from the United Kingdom?

When you meet the green card test or the substantial presence test (31 days this year and 183 weighted days over three years). Your residency starting date is generally your first day in the US that year, or your first day as a permanent resident.

What if I am resident in both the United Kingdom and the US?

Article 4 (Residence) of the treaty breaks the tie, starting with where you have a permanent home. Claiming treaty residence in the United Kingdom on a US return needs Form 8833.

Do I report my accounts in the United Kingdom after moving to the US?

Once you are a US resident, yes: the FBAR when foreign accounts total more than US$10,000, Form 8938 above higher thresholds, and PFIC rules for many foreign funds.

Is there a US social security agreement with the United Kingdom?

Yes, in force since January 1, 1985.

Sources

Every rule and figure on this page links to the IRS, CRA or other official source it comes from. Amounts change; we re-check them before each engagement.

Gurleen Kaur, CPA licensed in British Columbia and Washington State. Last updated November 11, 2026. This page is general information, not tax or legal advice for your situation.

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