Moving back to the US from the UK can create state tax before your first US federal return is due. The costly assumption is that a US arrival date, a new lease or a job start automatically gives one simple answer. States set their own residence, domicile and income-sourcing rules, so the date and the evidence around it matter.
This guide is for US citizens returning from the UK. It does not decide a particular state result. It sets out the records and questions to put in order before you move, especially if you have UK pay, a bonus, investments, a former US state or a high-income year.
1. Name every state that could have a claim
Start with more than the state where you expect to unpack your boxes. Write down:
- the state you last treated as home before the UK;
- the state where you plan to live after the move;
- the state where an employer will treat you as working;
- states where you own or rent property, run a business or perform work; and
- any state named in a partnership, trust, equity-compensation or payroll record.
Federal tax residence and state tax residence are different questions. A state may ask about your home, family, work, property and intent; it may also tax income that has a source in that state after you cease to be a resident. Do not use a 183-day rule as a national shortcut.
Use the US state tax nexus checker once you have this list. It is a planning screen for collecting connection facts and testing the financial impact of a chosen state. It cannot determine domicile, source an item of income or replace the instructions of the state that may tax you.
2. Put a date against the move, not just the flight
For the return year, make a timeline from the last UK workday through the first settled US living and work arrangements. Include the arrival date, lease or home completion, first in-state workday, school enrolment, vehicle registration, licence, voter registration and the dates an old US home becomes available or is let.
The point is not to manufacture a preferred answer. It is to preserve the facts that show when your circumstances changed. A short visit to view homes is different from moving household belongings, beginning an indefinite job and establishing an ordinary home, but the state’s own rules decide the consequence.
California illustrates why the sequence matters. Its Franchise Tax Board says a part-year resident pays tax on worldwide income received while resident and on California-source income while nonresident. Its residency material also distinguishes domicile from residence and looks to objective facts, not a statement of intention alone. That is an example, not a rule to apply outside California.
3. Separate domicile, physical presence and source income
“Domicile” usually describes the place you regard as your permanent home. “Residence” can be a tax definition with a different test. A person can have ties to more than one place, while a state may ask which ties carry the most weight under its rules.
New York is a useful reminder not to stop at a mailing address. Its tax department says a person may be a resident through domicile, or through the statutory-resident test when the conditions are met, including maintaining a permanent place of abode and spending more than 183 days in the state. Check the current New York definition if it is relevant; other states use different tests and terminology.
Then make a separate income list. Mark the payment and receipt date for each UK salary payment, bonus, share vest, pension withdrawal, interest, dividend, property payment and capital transaction. Add where the work was performed and whether a former state has a source connection. This avoids treating every payment after a US flight as identical.
4. Gather the records before UK accounts disappear
Download the records that will be harder to retrieve after your UK address or employer access changes. Keep them in one return-year folder with the US-state timeline:
- UK P45, final payslips, payslips for any overlap and bonus or equity statements;
- UK and US employment contracts, work-location records and travel days;
- UK tax return, tax calculation and proof of tax paid;
- property completion, tenancy, letting-agent and rental-income records;
- brokerage statements showing transaction and settlement dates; and
- US lease, purchase, utility, school, payroll and registration documents.
For a move on 1 October, for example, the useful question is not simply whether the person was in the US by year end. It is when each income item was received or earned, which state’s connection exists and whether the state treats the individual as resident at that point. The documents above let a preparer test those questions rather than reconstructing them months later.
5. Reset payroll and tax administration after arrival
Tell a new employer your current address and review federal withholding. The IRS says employees should submit a new Form W-4 to change withholding, and its estimator is a useful check when income, deductions or credits change. State withholding is separate: ask payroll which state it is using and compare that with the work location and your own residence analysis.
Update the IRS address rather than assuming postal forwarding will handle tax notices. The IRS says Form 8822 can notify it of a home mailing-address change; filing a return with the new address is another route. Check the equivalent process with the relevant state tax agency, insurer, bank and payroll provider.
Put the federal and state filing dates, expected UK tax payments, payroll start date and any estimated-tax dates in the US expat tax calendar. If UK income, investment income or self-employment will not be fully covered by payroll withholding, use the US estimated tax planner to organise scenarios. Neither tool calculates a final federal, UK or state liability.
6. Escalate the cases that do not fit a simple move
Get state-specific tax advice before the move date or a large transaction if you have stock options or restricted stock, a carried-interest or partnership allocation, a business, a trust, a home kept in a former state, a large gain, UK rental income or a return to a state with a detailed domicile or statutory-residency regime. Ask the adviser to address the return-year start date, income allocation, required returns and estimated-payment plan together.
This is also the point for a multi-year move planner if a UK sale, pension drawdown, equity event and US return will occur across several tax years. It helps put assumptions and cash flows in one model for an adviser review; it is not a legal residence opinion.
Guidance, not advice: the calculators organise facts, dates and comparisons. They do not decide domicile, state residency, treaty relief or the taxable source of a particular payment.
A practical return-to-US order
- List the former, destination and income-source states.
- Build the move timeline before travel and housing dates become hard to prove.
- Download UK pay, tax, property and investment records.
- Run the state tax nexus checker with cautious connection assumptions.
- Confirm payroll withholding and update the IRS and state mailing records.
- Review the return year before a bonus, sale, vesting or pension payment.
- Obtain state-specific advice where the facts involve substantial income, property or more than one state.
The most useful result is a dated file showing the move. It helps support a clean part-year return and a clear reply if a state asks.