No withholding, no exemption, and a currency bill

Figures relate to tax year 2026 (US) · 2026-27 (UK)

A British investor buys American government debt and the interest arrives with nothing taken off it. That feels like a result.

Then Britain taxes the coupon at your top rate, the gain at maturity, and the currency movement on top.

Three charges where you expected one.

Key takeaways

• Treasury bonds get no UK capital gains exemption, unlike gilts.
• A gain on sale or redemption is taxable here.
• Non-Americans usually suffer no US withholding on the interest.
• An American owner is taxed on the interest in both countries.
• Inflation-linked uplift is taxed annually in America before you get it.
• A strengthening dollar can create a sterling gain on its own.
• The account holding them may be reportable, not the bond.
• Buying through a fund changes the analysis entirely.

What are US Treasury bonds?

Debt issued by the American government, in bills under a year, notes to ten years and bonds beyond that. According to IRS guidance on interest income, the coupon is ordinary interest for American purposes. The credit risk is as low as anything available.

Our guide to UK gilts and US tax covers the British mirror.

Inflation-linked versions work differently again.

Is there US withholding?

Usually not for a non-American, because of the portfolio interest exemption. Interest on American government and most corporate debt paid to a foreign holder escapes the usual 30% deduction. You certify your status to the broker to get it.

Our guide to Form 1040NR for UK residents covers the nonresident return.

Still, without the form a broker may withhold anyway.

What if you are American?

Then the interest is simply taxable on your American return, and taxable here too because you live in Britain. A foreign tax credit stops the double charge. The portfolio exemption is irrelevant to you, since it exists for foreign holders.

Our guide to Form 1116 income baskets covers the credit.

Usually the interest sits in the passive basket.

Do you need a US tax number?

To certify your status to an American broker, often yes, and some accept a foreign number instead. A British holder buying through a British platform usually avoids the question entirely. Buying direct from America raises it.

Our guide to ITIN claims from the UK covers the claim.

Most British platforms handle the paperwork for you.

What about a British platform?

Most British brokers now offer American government debt directly, and they handle the the form for you. That removes the withholding question entirely. However it makes the account itself reportable if you are American.

Our guide to Form 2555 and the exclusion covers a related point.

Convenience on one side creates reporting on the other.

Does currency create a gain?

Often, and it catches people. Britain measures your gain in sterling, so a dollar that strengthened between buy and redemption produces a gain even where the bond price never moved. The bond did nothing and you owe tax.

Our guide to currency gains on UK bank accounts covers the same effect.

Record the exchange rate on every buy.

Should you hold them to maturity?

Holding to maturity keeps things simple, because there is one disposal and one working. Selling early adds a price movement on top of the currency movement. So the record keeping gets harder with every trade.

Our guide to the IRS online account covers a related point.

Also, frequent trading multiplies the paperwork.

Do treasury bonds go on your FBAR?

The bond itself is not an account, so what matters is where it is held. Treasuries in a British brokerage account make that account reportable on the usual threshold, and the same holding in an American broker does not.

Our guide to FBAR signature authority covers the account rules.

So the custodian decides this, not the issuer.

What about foreign asset reporting?

The same logic applies for an American owner. American government debt held through an American broker sits outside the foreign asset form, and the identical bond in a foreign account can bring it into scope. Where it sits is everything.

Our guide to Form 8938 reporting covers the thresholds.

A foreign custodian changes the answer entirely.

Is the interest taxed as income here?

Yes, as ordinary savings interest, at your top rate. So a higher rate payer loses 40% of the coupon and an extra rate payer rather more. The starting rate for savings rarely helps anybody holding a serious bond position.

Our guide to requesting a tax transcript covers a related point.

The personal savings allowance is small.

What about a discount on buy?

Buying below par builds in a gain you will realise at maturity, and Britain taxes that gain. America treats part of it as income under the market discount rules instead. So the two systems can treat the same money differently.

Our guide to registering for Self Assessment covers a related point.

So a different label can break the credit.

Does that break the foreign tax credit?

Sometimes, because a credit needs the same income taxed by both countries in the same year. If America calls it income now and Britain calls it a gain later, the relief does not line up. Then you really can pay twice.

Our guide to double taxation relief covers the mechanics.

Timing mismatches are the common cause.

What about inflation-linked bonds?

They carry a nasty timing feature on the American side. The inflation uplift to the principal is taxed each year as it accrues, even though you get nothing until maturity. People call it phantom income, and it is a real cash flow problem.

Our guide to UK investment bonds and US tax covers a different wrapper.

Meanwhile an American holder meets that charge every year.

How does Britain tax the uplift?

Britain usually waits until you realise it, which puts the two countries out of step. So an American here can pay American tax on the uplift years before Britain sees it, with no credit in either year. That mismatch is hard to fix.

Our guide to the UK tax year difference covers timing mismatches.

Holding inflation-linked Treasuries here is rarely efficient.

What about state tax?

Treasury interest is exempt from American state income tax, which is a genuine benefit to somebody living in New York and no benefit at all to somebody in Nottingham. Britain has no match exemption and taxes it as ordinary interest.

Our guide to state tax for expats covers lingering state filings.

So the exemption is wasted once you live abroad.

Does the treaty reduce anything?

The interest article gives taxing rights on interest to the country of residence, which supports the position already reached by the portfolio exemption. For an American the saving clause removes most of the benefit. Little changes in practice.

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

The treaty confirms the answer rather than improving it.

Do treasury bonds suit a non-dom?

The old remittance basis is gone, so the usual answer no longer applies. Everybody taxed here now faces the same treatment on them. First check your residence position, because the rules changed recently.

Our guide to the UK statutory residence test covers residence.

Advice written before 2025 is out of date.

What if you move back to America?

Then the position flips in your favour. American state exemption becomes useful, the British charge falls away, and the currency problem disappears. So a bond that suited you poorly here can suit you well there.

Our guide to moving back to the US covers the return.

Review the holding when you move, not afterwards.

A worked example

Take an illustrative case. A British investor buys a Treasury note well below par and holds it to maturity.

The coupon is modest and most of the return comes from the pull up to par at redemption.

On a gilt that uplift would be exempt from British capital gains tax entirely.

On the Treasury it is taxable, and the dollar movement across the holding period adds a further gain on top.

What records should you keep?

Buy contract notes with dates and dollar amounts, the exchange rate on each date, coupon statements, and the redemption or sale note. Those four produce a British working nobody can rebuild years afterwards.

Our guide to exchange rates on a US return covers conversion.

Also, brokers rarely report in sterling.

Who should ask before buying?

Anybody with a large holding, and anybody American. A Brit with a small position inside an ISA can ignore most of this. The rest of us need to run the numbers first.

Our guide to choosing a US-UK tax accountant covers getting help.

Ask before you buy, not after.

What do we check first?

Your residence, your passport, and the wrapper. Those three settle most of the answer in a few minutes. Then we look at the size of the holding and the term.

Our guide to split year treatment covers a related point.

Usually three facts decide it.

Do treasury bonds get the gilt exemption?

No, and this is the single most expensive misunderstanding here. Britain exempts gains on gilts from capital gains tax because they are qualifying corporate bonds in British law. An American government bond is not, so the gain is fully taxable.

Our guide to UK capital losses for US citizens covers the gains rules.

So the exemption is about British law, not about safety.

Why does that matter so much?

Because the gilt strategy depends on it. A British investor buying a low coupon gilt below par takes most of the return as an exempt capital gain. The same trade in treasury bonds produces a taxable gain instead, which changes the arithmetic completely.

Our guide to UK reporting fund status covers funds holding them.

In short, a low coupon Treasury is a poor substitute for a low coupon gilt.

Gilts against treasury bonds

Is a Treasury fund different?

Completely, and usually worse. An American fund holding Treasuries is a pooled investment the British system may tax badly without reporting fund status, and an American owner meets the offshore fund rules in reverse. Direct bonds avoid all of it.

Our guide to ISA alternatives for Americans covers the fund problem.

First check reporting status before buying any fund.

Can you hold them in a pension?

A British pension can hold them, and the wrapper removes the annual charges while the money stays inside. That is the cleanest way for a British investor to own them. An American needs to check the scheme qualifies under the treaty.

Our guide to US retirement accounts in the UK covers the schemes.

A pension solves the tax and locks up the money.

What about an ISA?

A stocks and shares ISA can hold them and shelters the return from British tax entirely. For an American that shelter is worthless, because the IRS ignores the wrapper and taxes everything inside it. The answer depends on your passport.

Our guide to lifetime ISAs and US tax covers the wrappers.

A British investor should use the ISA first.

When do treasury bonds make sense here?

Inside a pension or an ISA, or where you specifically want dollar exposure. Outside a wrapper and in sterling terms, a gilt usually beats them for a higher rate taxpayer because of the exemption. Yield alone is the wrong comparison.

Our guide to UK savings interest covers cash alternatives.

Instead compare after tax and after currency, not before.

Why do people reach for treasury bonds at all?

The yield is quoted loudly and the risk is famously low. So the comparison stops at the headline number. But a British investor pays British tax, and that is where the gilt loses less.

Our guide to UK dividend tax for Americans covers other income.

In short, yield before tax tells you very little.

How big does the difference get?

On a large holding it is material rather than marginal. A taxable gain of several thousand pounds at 24% is simply lost where the gilt match was exempt. Meanwhile the yield gap that prompted the trade was usually a fraction of a per cent.

Our guide to US tax deadlines for expats covers a related point.

Small yield gains rarely beat a tax exemption.

Are treasury bonds still worth owning?

Often yes, in the right place. Put them in a pension or an ISA. Then the tax falls away and the yield is yours to keep. Outside a wrapper, a gilt is the better buy for most people here, and the gap is wider than the yield suggests.

Our guide to UK pension lump sums covers the wrapper.

In short, the wrapper matters more than the bond.

How to handle US treasury bonds from Britain

1. Accept that no British capital gains exemption applies.
2. Compare them against gilts after tax, not on yield.
3. Certify your status so no US withholding is taken.
4. Record the exchange rate at every buy and sale.
5. Avoid inflation-linked versions if you are American.
6. Prefer a pension or an ISA wrapper where you can.
7. Check where the custodian sits for reporting purposes.
8. Treat a Treasury fund as a different question entirely.

Mistakes and penalties we see with treasury bonds

The first is buying a deep discount Treasury expecting the gilt exemption, and meeting a full capital gains charge at redemption.

The second is ignoring the currency movement and reporting a gain in dollars rather than sterling.

The third is an American holding inflation-linked bonds and paying tax yearly on money they will not see for a decade.

The fourth is buying a Treasury fund without checking its reporting status and losing the gain to income rates.

How US UK Tax Accountants helps

We compare them against gilts on an after tax basis, because the exemption gap is usually larger than any yield difference that prompted the question.

Then we deal with the currency side, which nobody expects. Our US federal returns service covers the American filing.

If you hold American government debt from here, get in touch before the next redemption.

Last reviewed 4 November 2026. This article is general details and not personal tax advice, and we do not give investment advice.