Figures relate to tax year 2026 (US) · 2026-27 (UK)
You move to London for a posting. Your American salary follows you, and so does the whole American tax system.
Embassy staff lose the one relief everybody else abroad relies on, because of who signs the cheque.
The test is who signs the cheque, not where the desk is. So a federal salary is simply not foreign income, however long you live here.
Key takeaways
- A federal salary cannot use the foreign earned income exclusion.
- The housing exclusion is closed to you as well.
- Britain usually exempts a posted officer's mission salary.
- Locally engaged staff are taxed here in the normal way.
- A spouse working locally can still use the exclusion.
- Social security keeps running on the American side.
- Your home state may still want a return.
- Foreign account reporting applies exactly as usual.
Who counts as embassy staff?
Two very different groups, and the tax answer splits along that line. Posted officers come from Washington on a diplomatic assignment. Locally engaged staff are hired in Britain, often British nationals, and they are treated quite differently.
Our guide to US expat tax basics covers the starting point.
So establish which group you are in first.
Why can't you use the exclusion?
Because the law excludes amounts paid by the United States or one of its agencies. According to IRS guidance on the foreign earned income exclusion, wages from the federal government are not foreign earned income at all. So the relief simply does not reach your salary.
Our guide to Form 2555 and the exclusion covers the claim.
The exclusion is for private sector pay.
What does that actually cost?
The exclusion covered up to $130,000 of earnings for 2025, so losing it is a big number on paper. However you are not paying twice, because Britain usually does not tax the mission salary either. So the loss is more apparent than real for a posted officer.
Our guide to US filing thresholds for expats covers the figures.
Still, you file a full American return every year.
Posted against locally engaged
| Feature | Posted officer | Locally engaged |
|---|---|---|
| Mission salary in the UK | Usually exempt | Taxed here |
| Foreign earned income exclusion | Not available | Not available |
| Foreign tax credit on salary | Nothing to credit | Available |
| UK national insurance | Usually outside | Usually payable |
| Self assessment | Often not needed | Often needed |
| State filing | Often continues | Depends on history |
Does Britain tax a posted officer?
Generally not on the mission salary, under the diplomatic immunities that follow the Vienna Convention. A posted officer who is not a British national and not permanently resident here sits outside the charge. Other income can still be taxable.
Our guide to the UK statutory residence test covers residence.
So the exemption covers the salary, not everything.
What about other UK income?
Rent from a British flat, bank interest here or a trading profit can all be taxable even where the salary is exempt. The immunity is narrow and attaches to the official role. So a letting business brings you into self assessment.
Our guide to UK rental income for Americans covers lettings.
Register if you have any British source income.
A worked example
Take an illustrative case. An officer posted to London for three years, paid from Washington, renting out a flat in Virginia.
The salary is taxed in America and exempt here, so no credit is needed on it either way.
The American rent is taxed in America and taxable here too, because they live here now.
So the only cross-border sum on the whole return concerns a property they never thought about.
Are locally engaged embassy staff different?
Completely. If you were hired in Britain, you pay British tax on the salary in the normal way, usually through a payroll arrangement. An American in that position claims a foreign tax credit rather than the exclusion.
Our guide to Form 1116 income baskets covers the credit.
Still, neither group can touch the exclusion.
Why is it closed to locally engaged staff too?
Because the test is who pays you, not where you sit. A local hire on a mission payroll is still being paid by an agency of the United States. So the same exception applies, even though the tax picture is otherwise different.
Our guide to double taxation relief covers relief instead.
The credit does the work the exclusion would have.
What about national insurance?
A posted officer generally stays in the American social security system and pays nothing here. A local hire usually pays British contributions. So the two groups build entitlement in different countries over the same years.
Our guide to the US-UK social security agreement covers the rules.
First check which system you are paying into.
Does your spouse get the exclusion?
If they work for a British employer, yes, and that is often the biggest planning point in the household. Their salary is ordinary foreign earned income. So one spouse claims the exclusion while the other cannot.
Our guide to the foreign housing exclusion covers the extra relief.
File jointly and the two reliefs sit side by side.
Can a spouse work at all?
Usually yes, under the arrangements that let dependants take local jobs, though the detail varies. Tax follows the employer rather than the visa. So a locally employed spouse is taxed here like anybody else.
Our guide to moving to the UK mid-year covers the first year.
Also check the work permission before accepting a job.
What about a mission contractor?
A contractor paid by a private company can use the exclusion, which is a real difference from direct employment. The same desk and the same building give different answers. So the contract matters more than the location.
Our guide to self-employment tax abroad covers contracting.
Read who the paying entity actually is.
Do you still file a state return?
Often yes, and federal employees abroad get caught by this more than most. A posting is not usually enough to break domicile with your home state. So Virginia, Maryland and the District keep appearing on returns years later.
Our guide to state tax for expats covers breaking domicile.
In short, a posting rarely changes your state position.
What about the Thrift Savings Plan?
Paying in reduces your American taxable income in the usual way. Britain generally does not tax the growth inside it while you are exempt on the salary. However the position changes if you stay on after the posting ends.
Our guide to US retirement accounts in the UK covers the schemes.
So review it before any change of status.
Do embassy staff file an FBAR?
Yes, on exactly the same terms as anybody else. Diplomatic status gives no relief from account reporting at all. So a British current account opened for convenience brings you into scope once the balances cross the threshold.
Our guide to FBAR signature authority covers the accounts.
Immunity from tax is not immunity from reporting.
What about Form 8938?
The same applies, and the thresholds are higher for somebody living abroad. Most posted officers only hold a current account and a cash ISA, which stays under them. A pension or investment account changes that quickly.
Our guide to Form 8938 reporting covers the limits.
So add up every account before deciding.
Can you open an ISA?
You can open one, and it rarely helps an American. Britain shelters the return and the IRS ignores the wrapper entirely. So a stocks and shares ISA can create more work than it saves.
Our guide to ISA alternatives for Americans covers the problem.
Meanwhile a cash ISA is simpler than a stocks one.
Does a British pension make sense?
Rarely for a posted officer, because you are not in British employment and the Thrift Savings Plan already covers you. A local hire is usually enrolled by default and should stay in. So the answer tracks your group again.
Our guide to employer pension contributions covers enrolment.
Do not opt out of a scheme without advice.
What happens when the posting ends?
If you leave, the British exemption falls away with the role and nothing much changes in America. If you stay on in private work, everything changes at once. That second case needs planning before you resign.
Our guide to split year treatment covers the change.
The handover date matters more than people expect.
What if you stay in Britain?
Then you become an ordinary American resident here, with British tax on worldwide income and a credit on the American return. The immunity was attached to the job, not to you. So the whole picture resets.
Our guide to becoming UK resident covers the switch.
Get advice in the quarter before you change jobs.
What about British mission staff in Washington?
The mirror image applies. A posted British officer is generally outside American tax on the mission salary, and a locally engaged American is taxed there normally. The same split runs in both directions.
Our guide to Form 1040NR for UK residents covers the nonresident return.
British nationals posted there still file at home.
Does the treaty help?
The government service article supports the position already reached, and the immunities do most of the work. For an American the saving clause removes much of the benefit anyway. So the treaty confirms rather than improves things.
Our guide to the US-UK tax treaty covers the articles.
First read the government service article.
What records should embassy staff keep?
Your posting letter with the dates, your federal pay statements, any British income records, and account statements for every British account. Those four answer almost every question that comes up later.
Our guide to exchange rates on a US return covers conversion.
Also keep the posting letter somewhere safe.
Who should get advice?
Anybody with British income beyond the salary, anybody whose spouse works locally, and anybody thinking of staying on. A plain posting with no outside income is usually simple. The complications sit around the edges.
Our guide to choosing a US-UK tax accountant covers getting help.
So ask before the situation changes, not after.
Why do embassy staff get a worse deal?
Not out of spite, but because the relief exists to stop double tax on foreign pay. Your pay is American, not foreign, so there is nothing to relieve. The logic holds up once you see it.
Our guide to US tax deadlines for expats covers the dates.
So the rule is narrow rather than unfair.
Does the housing exclusion apply?
No, because it rides on the main relief and falls with it. Embassy staff in expensive London housing often ask about this first. The answer is the same whichever way you come at it.
Our guide to UK rent and US tax relief covers housing costs.
Also, official housing follows its own rule again.
What about official quarters?
Housing provided as part of the posting is usually outside your taxable pay on the American side. So the benefit is real even though the relief is closed. Check your pay statement to see how it is shown.
Our guide to employer benefits and US tax covers benefits in kind.
Ask payroll how they handle the housing.
Do embassy staff need a UTR?
Only if you have British income to report. A posted officer with just the mission salary usually needs nothing from HMRC. The moment you let a property here, that changes.
Our guide to registering for self assessment covers signing up.
So the test is other income, not the job.
What about children born here?
A child born during the posting is American from birth, which brings its own filing questions in time. Get a social security number early. The credit needs a number before you can claim it.
Our guide to the child tax credit abroad covers the claim.
Apply for the number early, because it is slow.
Can embassy staff claim the child credit?
Yes, and more easily than most expats. The refundable part is blocked for anybody using the main exclusion, and you cannot use it anyway. So the credit is often worth more to you than to a private sector neighbour.
Our guide to the additional child tax credit covers the refund.
In short, the closed relief helps you here.
Is that a real advantage?
It is, and almost nobody notices it. A family using the exclusion gives up the refundable credit, worth up to $1,700 per child for 2025. Embassy staff keep it, because they never claimed the exclusion.
Our guide to US tax refunds from abroad covers getting paid.
So run the credit before assuming you lose out.
How long does a posting last?
Most run two or three years, with an option to extend. That length matters, because it keeps you clearly resident here for British purposes. So the residence test rarely causes argument.
Our guide to the UK tax year difference covers the two calendars.
Short details of a few months work differently.
What about a short detail?
A few months on temporary duty may leave you outside British residence entirely. Then the question never arises, and you simply file at home. Count your days carefully either way.
Our guide to the 183-day rule covers day counting.
So keep a travel log from day one.
How to handle tax as embassy staff
- Establish whether you are posted or locally engaged.
- Accept that the exclusion cannot cover your salary.
- Check whether the British exemption applies to you.
- Register here if you have any other British income.
- Claim the exclusion on a spouse's local salary.
- Keep filing your home state return unless it is clearly broken.
- Report every British account on the usual forms.
- Take advice before the posting ends or you change jobs.
Mistakes and penalties we see with embassy staff
The first is claiming the exclusion on a federal salary, which fails on review and costs interest.
The second is assuming the immunity covers rent or interest as well as the salary.
The third is dropping the home state return on the strength of being abroad.
The fourth is missing the account reports, where the penalties are the harshest in the whole system.
How US UK Tax Accountants helps
We sort out which group you fall into, then work out whether anything beyond the salary needs reporting here.
Then we look at the spouse, who usually has the better relief. Our US federal returns service covers the American filing.
If you are on a posting between the two countries, get in touch before the next filing season.
Last reviewed 4 November 2026. This article is general information and not personal tax advice.
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Get in TouchPrimary sources
Official guidance from the IRS, FinCEN and GOV.UK. Thresholds and rates on those pages are updated annually — check the current tax year before relying on a figure.
- IRS — U.S. citizens and resident aliens abroad (opens in a new tab)
- IRS — Foreign earned income exclusion (opens in a new tab)
- IRS — Federal, state and local governments (opens in a new tab)
- IRS — Tax treaties (opens in a new tab)
- GOV.UK — Tax on foreign income: UK residence and tax (opens in a new tab)
