A second passport changes less than people hope

Figures relate to tax year 2025-26 (UK) · 2025 (US)

You have been here long enough to qualify, the fee is painful but payable, and the form is sitting open. Then somebody mentions tax.

Here is the short answer. British citizenship changes nothing about what you owe America, because America taxes the passport you already hold.

It does change a few things at the edges, and one of them matters a great deal if you ever think about giving the American one up.

Key takeaways

• Naturalising does not reduce or end your US filing duty.
• America taxes citizens wherever they live and whatever else they hold.
• Britain permits dual nationality, and so does the United States.
• A handful of treaty articles turn on which nationality you hold.
• Government pensions are the clearest example of that.
• It makes no difference to FBAR or foreign asset reporting.
• It can change the picture if you later renounce.
• The decision is about life, not about tax.

Does British citizenship change your US tax?

Not in itself. The United States taxes its citizens on worldwide income wherever they live, and acquiring another nationality does nothing to that. According to IRS guidance for citizens abroad, the filing duty follows the American passport regardless of what sits beside it in the drawer.

Our guide to Americans living in the UK covers the baseline position.

You file exactly as you did the week before the ceremony.

Can you hold both passports?

Yes, comfortably. According to GOV.UK guidance on dual citizenship, Britain allows you to hold another nationality alongside a British one, and the United States does the same. Hundreds of thousands of people live in exactly that position without anybody objecting.

Neither country asks you to give up the other.

Travel on the passport of whichever country you are entering.

Does Britain tax you differently afterwards?

No. British income tax follows residence rather than nationality, so a resident American and a resident British citizen are taxed identically. Naturalising changes your immigration position and your right to vote, not the rate on your salary.

Our guide to the statutory residence test covers how Britain decides.

Residence is what moves your British tax, and it always was.

What about inheritance tax?

Here nationality has never been the test either, and the rules now turn on long-term residence instead. So the citizenship certificate does not pull your estate into British inheritance tax, though the years you spent here to qualify may well have done.

Our guide to long-term residence and IHT covers the current rules.

The clock that matters is the residence one.

Which treaty articles turn on citizenship?

A small but important group. The government service article leaves a state pension or civil service pension to the paying country unless the recipient is a national of the other one, which is precisely the position you create by naturalising. That single change can move where a pension is taxed.

Our guide to the US-UK tax treaty covers the articles usually.

Read the government service article before you apply if a public pension is in play.

What changes and what does not

Does it affect FBAR?

Not at all. The reporting duty attaches to being a United States person, and a second nationality does not remove that status. Your British accounts remain reportable on exactly the same thresholds the day after the ceremony as the day before it.

Our guide to FBAR signature authority covers the account rules.

People assume this one changes, and it never does.

Does it affect foreign asset reporting?

The same answer, for the same reason. The asset reporting form follows United States person status, which naturalising elsewhere leaves untouched. Nothing about your investments, pensions or company interests falls out of scope because you now hold a second passport.

Our guide to Form 8938 reporting covers the thresholds.

Both filings continue unchanged indefinitely.

Why do people think it helps?

Because most countries tax residence rather than nationality, so the instinct is reasonable everywhere except America. Somebody who moves from France to Britain genuinely does leave the French system behind. The American rule is the outlier, and that is why the confusion is so persistent.

Our guide to the accidental American covers the same misunderstanding.

In our practice this is the single commonest hope we have to disappoint.

Does British citizenship matter if you renounce?

Enormously, and this is the real tax argument for taking it. You cannot give up American citizenship if doing so would leave you stateless, so holding another nationality is a practical precondition. Naturalising first is what makes the option exist at all.

Our guide to renouncing US citizenship covers the process.

Settled status is not a nationality for this purpose.

Should you naturalise before renouncing?

You have very little choice about the order. The British claim takes months and the American renunciation needs the second passport in hand, so the sequence builds itself. Anybody seriously considering giving up the American passport should start the British process well ahead.

Our guide to the cost and process of renouncing covers the timing.

Allow a year between starting one and finishing the other.

Does it trigger the exit tax?

No. The exit charge applies when you renounce, not when you pick something else up. For 2025 the covered expatriate net worth test still sat at $2 million, and taking a second passport does not bring you near it. Nothing is valued, reported or charged.

Our guide to the exit tax and Form 8854 covers the charge itself.

The two steps are years apart for most people.

Is there a dual national exception?

There is one worth knowing, and it is narrow. Somebody who became a citizen of both countries at birth and has limited American residence can escape covered expatriate status on renunciation. Naturalising as an adult does not put you in that group.

Our guide to covered expatriates and gift tax covers that status.

Read the condition carefully, because almost nobody meets it.

A worked example

Take an illustrative case. An American who has lived in Manchester for a decade naturalises in the spring.

Her American return for that year looks identical to the previous one.

Her British return looks identical too, because residence never changed.

What did change is that renouncing is now an option she could actually take, which was not true in January.

What does the claim cost?

The fees run well into four figures for an adult once the claim and the ceremony are counted. More again if you need a test or a document check. None of it is deductible on either return, so treat it as a personal cost rather than a tax one.

Fees rise most years, so check the current figure on GOV.UK before you budget.

Children cost less but are not free.

Does it affect your children?

British citizenship may pass to them, which is a genuine benefit, but their American status is unaffected. A child born in Britain to an American parent is usually American already, and nothing about your naturalising changes that or their eventual filing duty.

Our guide to a child born abroad covers their position.

Plan their American affairs separately from the passport question.

Does it help with banking?

Less than you would hope. British banks ask about American status rather than British status, so a dual national is still reported under the details exchange rules. The account opening questions are the same ones, with the same answer.

Our guide to a FATCA letter from a UK bank covers those questions.

Investment platforms stay just as difficult afterwards.

Does it change your state tax position?

Only indirectly. A handful of states chase former residents on the basis of continuing ties, and the argument you have severed them is easier to make once you hold the other passport. It is evidence rather than a rule.

Our guide to state tax for expats covers the stubborn states.

Evidence of permanence helps, but nothing settles it alone.

Does it affect social security?

No. Contributions and entitlements in both systems follow where you worked and paid, not which passports you hold. The agreement between the two countries continues to govern the position exactly as it did before.

Our guide to a certificate of coverage covers the contributions.

Your record in each country stays where it was.

Do you tell the IRS?

There is no form for it and no box to tick. Naturalising abroad is not a reportable event, and your returns simply carry on. The State Department will hear about it eventually if you ever renounce, and not before.

Our guide to US tax deadlines for expats covers the ordinary filings.

Keep the certificate safe, because renunciation needs it.

Does holding British citizenship simplify anything?

In daily life, a great deal: the right to remain, to vote, to leave and return freely, and an end to immigration fees. In tax terms the honest answer is almost nothing, beyond the treaty articles and the renunciation door. Most people apply for the first set of reasons.

That is a perfectly good reason to do it.

Just do not expect the American paperwork to shrink.

What records should you keep?

The naturalisation certificate, the ceremony date, and the passport itself once issued. Those three prove your position whenever anybody asks, and the certificate in particular is needed years later if you renounce. Replacements are slow and expensive.

Store the certificate with your birth certificate, not with bank papers.

Scan it the week it arrives.

Do you give up the US passport?

No. Nobody asks you to hand it in, and nothing happens to it. You simply hold two. The oath at the ceremony is about loyalty to the Crown, and it does not ask you to give up anything you already have.

Keep both passports in date and use each one at its own border.

An American must enter and leave America on the American one.

How long does British citizenship take?

Months rather than weeks. The Home Office aims to decide inside six months, and many cases take longer. Then you wait for a ceremony place, and after that for the passport itself. Plan on the better part of a year from start to finish.

Nothing in the tax year turns on when it lands.

So there is no clever date to aim for.

Does the ceremony date matter?

Only for your own records. Your American tax year is not split by it, your British one is not either, and no return asks about it. The date matters later, when a form wants to know when you became British.

Write it down somewhere you will still have in ten years.

People forget it, and the certificate is the only proof.

What if you move back to America?

You keep the British passport. Britain does not take it away for living elsewhere, and there is no residence test to hold on to it. Your tax then follows where you live, so the American system takes over and the British one steps back.

Our guide to moving back to the US covers that move.

The passport is useful if you ever come back.

Does British citizenship touch a US pension?

Only a government one. A private pension or a workplace plan follows the treaty rules on residence, which your passport does not change. A federal or state pension can move, because that article asks what nationality you hold.

Our guide to US retirement accounts in the UK covers private plans.

Ask about this before you apply if you drew a public salary.

Is it worth it if you might leave?

Usually yes, because it is permanent and settled status is not. Indefinite leave can lapse after a long absence, and citizenship cannot. So people who expect to move around often value it more, not less.

The cost is one-off and the right is for life.

That is a life decision rather than a tax one.

Does British citizenship change your tax code?

No. HMRC sets your code from your income and your allowances, and it has never asked about nationality. British citizenship leaves the code exactly where it was, so the first payslip after the ceremony looks like the last one before it.

Our guide to your P60 and the US return covers the British payroll record.

Tell HMRC about a change of address, not a change of passport.

How to plan around British citizenship

1. Expect your American filing duty to carry on unchanged.
2. Check the government service article if a public pension is involved.
3. Keep filing FBAR and the asset form on the same thresholds.
4. Treat the fee as a personal cost, not a deductible one.
5. Consider your children's British entitlement separately from their American status.
6. If renouncing interests you, start the British claim first.
7. Keep the certificate somewhere you can find it in ten years.
8. Review your state tax position once you hold the passport.

Mistakes and penalties we see around British citizenship

The first is quietly stopping American filings after the ceremony, in the belief that the second passport replaced the first.

The second is answering a bank's American status question in the negative because the new passport feels more current.

The third is renouncing on the assumption that naturalising already dealt with the exit charge.

The fourth is missing a pension that moved between countries under the government service article.

How US UK Tax Accountants helps

We set expectations honestly first, because most people arrive hoping the second passport solves a problem it cannot touch.

Then we look at the two places it genuinely matters: public pensions, and the renunciation route. Our expatriation service covers the second.

If you are applying and want the tax picture straight, get in touch.

Last reviewed 27 October 2026. This article is general details and not personal tax advice, and nationality law is outside our field.