The Lifetime ISA and the IRS: why the government bonus is not free for Americans

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

The Lifetime ISA is one of the better deals in British saving. Put in £4,000 a year and the government adds £1,000, free of UK tax whenever you take it out. For an American saver, the IRS treats that bonus as income.

The account can still be worth holding, but the version you choose changes everything. So this guide covers the US treatment of the bonus, the fund problem inside the stocks and shares version, and when the account still makes sense.

Key takeaways

• The 25% government bonus is tax-free in Britain and generally taxable in America.
• The IRS ignores the ISA wrapper, so income and gains inside are taxable each year.
• A stocks and shares version usually holds funds, which brings PFIC reporting.
• A cash version avoids the fund problem but still produces taxable interest.
• The account counts toward your FBAR threshold like any other UK account.

What is a Lifetime ISA?

A Lifetime ISA is a British savings account for a first home or for retirement. You can open one between 18 and 39, and pay in up to £4,000 each year until you turn 50. The government adds 25% on top, up to £1,000 a year.

According to the GOV.UK guidance on the Lifetime ISA (opens in a new tab), you can withdraw for a first home worth up to £450,000, or from age 60. Take the money out for anything else and a 25% withdrawal charge applies, which can leave you with less than you paid in.

Britain hands you a bonus and taxes none of it. America taxes the bonus and hands you nothing.

Why does the IRS tax the bonus?

Because America taxes worldwide income and gives no recognition to British savings wrappers. The bonus is money you received, so it generally counts as income in the year it lands. No treaty article protects it in the way pension articles protect a workplace scheme.

There is no UK tax on the bonus either, which removes the usual defence. A foreign tax credit only offsets tax you actually paid, so an American saver meets the full US rate on money Britain never touched.

For a basic saver the sums are modest. A £1,000 bonus might add a couple of hundred dollars of US tax, which many people accept as the price of a £1,000 gift.

What happens inside a stocks and shares version?

That is where the real cost appears. Most stocks and shares accounts hold UK funds, and the IRS treats those funds as passive foreign investment companies. Each holding brings punitive rates and its own Form 8621 every year.

Per the IRS guidance on Form 8621 (opens in a new tab), a separate form is required for each fund you hold. Our guide to the ISA and PFIC problem explains how quickly the preparation cost can exceed any growth.

The cash version avoids that entirely. Interest is taxable in America each year, but interest is simple to report and the rates are ordinary.

Does the account need reporting?

Yes, in the same way as any other British account. The balance counts toward the $10,000 FBAR threshold when added to your other accounts. Per the FinCEN guidance on foreign accounts (opens in a new tab), the test looks at the combined maximum during the year.

Form 8938 may apply above its own higher thresholds. Our guide to Form 8938 and the other international forms sets out which ones your holdings actually trigger.

Some advisers go further and treat ISAs as foreign trusts, which would add more forms again. That view is not universal, and in our practice most accounts are reported as ordinary financial accounts.

How does it compare with a workplace pension?

For retirement saving, a workplace pension usually wins. Employer contributions add money a Lifetime ISA never matches, and the treaty protects growth inside a UK pension from annual US tax. That protection is the part savers most often overlook.

The account still has a place for the first-home goal, where a pension cannot help at all. Many people use both, for different purposes and different timescales.

Salary sacrifice complicates the comparison further, since it reduces UK tax and National Insurance at once. Model both before committing a large share of your savings.

Is the account still worth opening?

Often yes, for a first-time buyer saving in cash. A guaranteed 25% bonus beats almost any return available elsewhere, and the US tax on it takes only a slice. The maths changes once funds and their reporting enter the picture. Run the comparison with real numbers rather than assuming the bonus always wins.

Think about your timeline too. Money you may need before buying a home, or before 60, faces the withdrawal charge. That charge is a British cost with no American relief attached to it. Money you might need for a car, a wedding or an emergency belongs somewhere else entirely.

How do you handle one properly?

Decide the version before you open the account, because switching later means selling holdings and starting again. A Lifetime ISA is simple to run for a US filer once that choice is right. These steps keep the American side manageable:

1. Choose the cash version unless you have advice covering the fund reporting.
2. Record the bonus each year, with the date it arrived.
3. Convert the bonus and any interest into dollars at the rate on that date.
4. Report the income on your US return, even though Britain exempts it.
5. Add the balance to your other accounts for the FBAR threshold test.
6. Keep annual statements showing contributions, bonus and growth.
7. Review the position before any withdrawal, especially before buying.

What if you already hold funds inside one?

You have three practical choices. Keep the funds and file the forms, switch to cash inside the same Lifetime ISA if your provider allows, or transfer to a cash version elsewhere. Transfers between ISAs keep the wrapper intact.

Selling the funds is a US taxable event in the year of sale, and the PFIC rules can tax that gain harshly. So run the numbers before acting, because a rushed exit sometimes costs more than another year of reporting. A single year of tidy reporting often beats a hasty sale.

Keep every statement showing what you held and when you sold. PFIC calculations depend on holding periods, and reconstructing them later is slow work.

When the bonus actually arrives

Providers claim the bonus monthly, usually a few weeks after each contribution. That matters for American reporting, because the income belongs to the year the bonus lands rather than the year you paid in. Ask your provider for a statement listing every bonus payment with its date.

A contribution made in March can produce a bonus in April, landing in a different UK tax year and possibly a different US one. Keep the provider statements showing each payment date.

A worked example

Take an illustrative example. An American teacher in Bristol saves the full £4,000 into a cash Lifetime ISA for four years while house-hunting. Each year the government adds £1,000, and the account earns modest interest.

She reports about $1,300 of bonus each year on her US return, plus the interest. At her marginal rate that costs perhaps $280 a year. Over four years she pays roughly $1,100 of US tax to collect £4,000 of bonus.

Her colleague chose the stocks and shares version. His growth was better, but three funds meant three Forms 8621 every year, and preparation fees that swallowed most of the difference.

What happens when you buy the house?

Nothing changes on the American side at that point. The withdrawal itself is not a taxable event, because you already paid US tax on the bonus and the growth as they arose. The purchase is simply a use of your own money.

Keep the paperwork anyway. Records showing what you already declared prevent the same money being taxed twice if your preparer changes, which happens more often than you might expect. A simple annual summary is enough, provided it shows the bonus, the interest and the dates.

The £450,000 property cap

The house price cap catches buyers in London and the South East most often. A first home above £450,000 cannot be bought with these savings without triggering the withdrawal charge.

The cap has not moved since the scheme began, while prices have. So check the current limit before relying on the account for a purchase in an expensive area. Buyers in expensive areas sometimes save in the account for years, then find their target home sits just above the line.

Mistakes and traps with a Lifetime ISA

Most problems come from treating the account as invisible to America. These are the ones we see most often:

• Leaving the government bonus off the US return because Britain exempts it.
• Opening the stocks and shares version without pricing the fund reporting.
• Forgetting the balance when adding up accounts for the FBAR.
• Assuming a foreign tax credit covers the bonus, when no UK tax was paid.
• Withdrawing early and meeting the 25% charge without planning for it.
• Switching preparers without records of what was already declared.

Savers who want simplicity sometimes prefer a different route entirely. Our guide to Premium Bonds and US tax covers one British product that avoids fund reporting altogether.

How US UK Tax Accountants helps

We price the American cost of each version before you commit, then report the account correctly every year. Our PFIC reporting service covers funds held inside British wrappers, including Form 8621 preparation.

In our practice the cheapest advice is given before the account opens. We agree a fixed fee in writing before any work starts.

Check before you open one

If a Lifetime ISA is part of your plan for a first home, a short review shows what it really costs you in America. Tell us what you hold and what you intend to save. You can book a consultation and hear back within one working day.

Last reviewed 16 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.