State tax after you leave: the bill that follows Americans abroad

Figures relate to tax year 2025 (US)

State tax does not stop at the border simply because you moved to London. Each state runs its own state tax residency rules. Several keep taxing former residents until those residents prove they truly left, which can take years. Federal filing gets all the attention, yet the state tax bill is the one that surprises people years later.

The good news is that this is solvable, and mostly with paperwork rather than money. So this guide covers which states cling hardest and how residency actually breaks. It also sets out what to file from Britain, plus the evidence that settles an argument before it even starts.

Key takeaways

• States tax on their own residency rules, entirely separately from the IRS.
• California, New York, Virginia, New Mexico and South Carolina are the traditional sticky states.
• Domicile plus statutory day counts decide residency in most states.
• Many states ignore the federal foreign earned income exclusion completely.
• Breaking residency is an evidence exercise: cut ties, document the move, file a part-year return.

What is state tax residency?

It is a state's own test for whether you belong to it for tax purposes. Most states use two routes: domicile, meaning your permanent home, and a statutory test based on days present plus a place to live. Meet either one and the state can tax your worldwide income.

Because each state writes its own rules, no single answer covers everyone. The IRS maintains a directory of state government websites (opens in a new tab), which is the right starting point for the state you actually left. Two people leaving on the same day can face completely different outcomes.

Which states are hardest to leave?

A handful of states presume you remain a state tax resident until you prove otherwise, and they interpret the evidence strictly. The rest generally accept a genuine move without argument. Knowing which camp your state sits in tells you how much work the exit needs.

The pattern is about attitude rather than rate. A state with modest rates but aggressive enforcement can cost more than a higher-rate state that lets people go quietly. The fees and the stress both add up. In our practice we see California cases outnumber every other state combined.

The IRS wants your return. A sticky state wants your intent — and it reads your paperwork to find it.

How do you break state tax residency?

You break it by moving your life, then proving you moved it. Intent matters, but only as evidenced by actions. So the work is practical rather than philosophical. Sever the connections that say you still live there, and build a clear record showing where you live now.

1. File a part-year resident return for the year you left, showing the departure date.
2. Close or reassign the ties: driver's license, voter registration, and in-state vehicle registration.
3. Move your bank accounts and update every single address, including subscriptions and professional bodies.
4. Sell or genuinely rent out the home, at arm's length and for market rent.
5. Register locally in the UK: council tax, GP, National Insurance, tenancy or purchase.
6. Keep travel records, because return visits feed statutory day counts.
7. Retain the evidence for at least four years, since state audits often arrive very late indeed.

Do states follow the federal exclusion?

Often not, and this is where the surprise bills come from. The federal foreign earned income exclusion removes a slice of salary from your US return. Many states never adopted it, so income you excluded federally can still be fully taxed by the state.

Per the IRS guidance on the exclusion (opens in a new tab), it applies to your federal return. State conformity is a separate question with a separate answer in every state. Anyone relying on the exclusion should check state treatment before assuming their bill is zero.

What about credits for the UK tax you paid?

Most states offer no credit for foreign tax at all. Federal returns relieve double taxation through the credit mechanism. Our guide to Form 1116 and the foreign tax credit covers how that works in detail. States rarely mirror it, which is why residency matters so much more at state level.

That asymmetry sets the strategy. Federally, you argue about credits and exclusions. At state level, you argue about whether you are a resident at all, because residency is usually the only lever that changes the answer. Everything else follows automatically from that single determination.

Domicile versus the statutory test

Two doors lead into state tax residency, and you only need to walk through one. Domicile asks where your permanent home sits — the place you intend to return to. It follows intent, so it survives long absences and changes only when you establish a new one.

The statutory test asks something blunter. Did you keep a place to live in the state, and did you spend more than a set number of days there? New York uses 183 days with a permanent place of abode. Meet that pair and intent becomes irrelevant.

So a clean exit closes both doors. Change your domicile by genuinely settling elsewhere. Then keep the day counts low enough that no statutory test catches you on the rebound. Missing either half leaves the state tax question unresolved.

What does the exit actually cost?

Usually far less than people fear. A part-year return in the year of departure is routine work, and most states then disappear from your filing life entirely. The cost sits in the year of the move, not in the years afterward. One tidy filing buys a decade of silence from a state that would otherwise keep writing.

Cleaning up a botched exit costs more. Late returns, interest and reconstructing evidence from years ago all add hours. So the cheap version of this project is the one you do on the way out, while the licenses, leases and tenancy papers are still in front of you. Six years later, those same documents take weeks to gather, and some never resurface at all.

A worked example

Take an illustrative example. A software engineer leaves San Francisco for London in March 2025. She keeps her California driver's license, her apartment lease and her local bank, expecting to return within two years. She files a federal return and nothing else.

California sees an unchanged domicile. Her $180,000 salary, though excluded and credited federally, remains fully taxable there, and the exclusion does not apply. Suppose she had surrendered the license, ended the lease and registered properly in the UK. The same year would then have produced a part-year return and a clean break.

The mistakes and penalties that follow a sloppy exit

State tax problems build silently, because no letter arrives until an audit opens. By then interest has run for years. These are the errors that create the exposure:

• Filing federal returns but never filing a final part-year state return.
• Keeping a driver's license or voter registration purely for convenience.
• Leaving a home available for personal use, which supports a place of abode argument.
• Assuming the federal exclusion carries into state calculations.
• Spending long stretches back in state without counting the days.
• Discarding evidence of the move after a year or two, before the audit window closes.

One more compounds the rest: forgetting that state estimated payments follow their own schedule where a bill remains. We cover the federal quarters in US estimated tax payments from the UK, and any state layer sits alongside them rather than inside them.

What if you kept property back home?

Property alone rarely makes you a resident, yet it complicates both arguments. A rented-out house generates state-source income, so a non-resident return usually follows each year. A house kept empty for your own use looks far more like a continuing home, which is exactly what a sticky state wants to find.

So structure matters here. Rent at market rate through an agent, keep the tenancy paperwork, and avoid keeping a room reserved for your own visits. The rental income creates a filing duty you can satisfy easily each year. The empty bedroom, by contrast, creates an argument you may well lose.

Returning home later: what to expect

Moving back restarts residency in the state you return to, usually from the day you arrive. That produces another part-year return, and it reopens questions about the years abroad if the exit was never clean. A tidy departure therefore protects the return trip too.

Plan the arrival date with the same care as the departure. Income realized just before or after the move can land in very different places. Bonuses, share vestings and property sales are the usual candidates, and timing them well is ordinary planning rather than anything exotic.

How US UK Tax Accountants helps

We handle the state tax layer alongside the federal return through our US federal returns service. That means the part-year filing for the year you left, any continuing non-resident returns, and a documented view of when residency ended and why.

Because we prepare the UK side too, your evidence comes from filings we already made. One senior specialist owns the whole picture, on a fixed fee agreed in writing before work begins. For the wider annual position, our guide to what Americans in the UK actually file sets out the federal shape.

Settle your state position now

If you left a sticky state without a clean break, your state tax exposure grows quietly every year you ignore it. Tell us which state you left and what you kept there. We will assess the position, plan the fix, and quote a fixed fee in writing. Book a consultation and hear back within one working day.

Last reviewed 8 September 2026 by the US UK Tax Accountants Tax Team. This article is general information, not personal tax advice — speak to a qualified US/UK tax adviser about your own position.

For the neighbouring question, Moving back to the US: the tax year that decides everything walks through it in detail.