Fifteen per cent off, and two countries counting it

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

An employee share purchase plan is the simplest benefit in the handbook. Money comes off your pay, and twice a year you buy ESPP shares at a discount.

For an American working in Britain it is one of the easiest things to report wrongly, because the discount is income in both places at different moments.

Get it wrong and you pay tax twice on the same money, which happens more often than anybody admits.

Key takeaways

• The discount is employment income, not a capital gain.
• Britain taxes it when the shares are acquired.
• America taxes it at purchase or at sale, depending on the plan.
• A qualified plan defers the American charge until you sell.
• British payroll usually collects its tax at once.
• Your base cost differs between the two countries.
• Forgetting the base cost adjustment taxes the discount twice.
• Selling in the same tax year keeps the credit usable.

What are ESPP shares?

Shares bought through a workplace plan at a set discount to market value. Contributions come out of pay over an offering period, and the plan buys at the end of it. The American rules capped contributions at $25,000 of share value a year for 2025, and a 15% discount is the common design.

Our guide to US-UK share schemes covers the wider family.

Discounts of fifteen per cent are the common design.

When does Britain tax ESPP shares?

At acquisition, because the discount is employment income the moment you get the shares. According to GOV.UK guidance on employee share schemes, a plan without British tax approval produces an income charge at that point, usually collected through payroll.

Our guide to the UK share incentive plan covers a British approved scheme.

An American plan is almost never approved here.

When does America tax ESPP shares?

It depends entirely on the plan's status. A qualified plan defers the charge until you sell, while a non-qualified one taxes the discount at purchase like Britain does. Most large American employers run the qualified version.

Our guide to CSOP options for US citizens covers a British option scheme.

Check the plan document rather than guessing.

Two countries, two moments

Why does the timing mismatch matter?

Because a credit needs tax in both countries on the same income at roughly the same time. Britain charges at purchase and a qualified American plan charges at sale, so the two charges can sit years apart with no credit bridging them.

Our guide to Form 1116 income baskets covers the credit.

In our practice this is the expensive part of the whole arrangement.

What is a qualifying disposition?

A sale that happens after both American holding periods are met, which usually means two years from the offering date and one from purchase. Meeting them turns most of the growth into a capital gain rather than ordinary income.

Our guide to the wash sale rule covers the disposal rules.

The discount itself is still ordinary income either way.

A worked example

Take an illustrative case. An American in London buys through the plan at a fifteen per cent discount.

British payroll taxes the discount as pay in the month of purchase.

Her qualified American plan charges nothing until she sells three years later.

Unless her return adds the British taxed amount to her American base cost, the same discount is taxed twice over.

How do you avoid the double count?

By adjusting your American base cost upwards for the amount already taxed in Britain. The broker statement will not do this for you, because the broker knows nothing about British payroll. It is a manual correction every time.

Our guide to UK bonus payments and US tax covers employment income.

Broker statements understate base cost on almost every plan.

Does national insurance apply?

To the discount, yes, like any other employment income. National insurance cannot be credited against American tax, so it is a real cost with no relief anywhere. Many plans also pass the employer charge to the employee by agreement.

Our guide to a certificate of coverage covers contributions.

Check whether you signed a charge transfer election.

What happens when you sell ESPP shares?

Britain charges capital gains tax on the growth above the value already taxed as income. America splits the proceeds between ordinary income and gain depending on the holding periods. Both computations start from different numbers.

Our guide to UK capital losses for US citizens covers the British side.

Keep every purchase confirmation for the base cost.

Should you sell ESPP shares straight away?

Many people do, and for an American here it often makes sense. Selling immediately keeps the two charges close together in time, which is what preserves the credit. The trade is giving up any potential growth.

Our guide to a second opinion on an expat return covers reviewing past years.

Holding for the American periods can strand the credit.

Does the exchange rate move ESPP shares?

Considerably, because the two countries measure in different currencies. The discount is a sterling figure for Britain and a dollar figure for America, converted at different dates. A moving pound alone can create a difference between the two.

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

Record the rate on each purchase date.

What does your employer report?

The British payroll figure and an American information statement, and they rarely agree. The American statement reports the plan's view while payroll reports the British charge, so reconciling them is your job rather than theirs.

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

Ask the plan administrator for a transaction history.

Do ESPP shares go on your FBAR?

The shares themselves usually sit in an American brokerage account, which is domestic and outside the filing. A British nominee account holding them would be a different matter. Check where the plan actually custodies them.

Our guide to FBAR signature authority covers the rules.

Most plans use an American broker.

What happens to ESPP shares if you leave?

The current offering period usually ends and contributions are refunded, with shares already bought staying yours. Leaving does not accelerate any charge, though it does stop future purchases. The holding periods carry on running.

Our guide to redundancy pay and US tax covers leaving.

Move the shares to your own broker before you go.

What if you move countries?

The charge can be apportioned by where you worked during the offering period, which is fiddly and worth doing properly. Somebody who bought while in Britain and sells after moving has two countries with partial claims.

Our guide to apportioning UK employment income covers the split.

Keep a record of where you worked each month.

Are ESPP shares worth joining?

Usually yes, because a fifteen per cent discount is a large guaranteed return even after tax. The tax friction described here reduces the benefit without removing it. Very few people should decline the plan on tax grounds alone.

Our guide to benefits in kind and US tax covers other employer provision.

Budget for the tax rather than avoiding the plan.

Does a lookback make it better?

Considerably, and many plans have one. A lookback prices the purchase against the lower of the start and end values, which can make the real discount far larger than the headline figure. It also increases the taxable amount.

Our guide to US citizens on a cap table covers private company shares.

More discount means more income, not more gain.

What records do ESPP shares need?

Each purchase confirmation with its price and date, the payroll entry showing the British charge, the exchange rate used, and the plan rules. Those four let you compute an American base cost nobody else will give you.

Our guide to a tax transcript request covers American records.

Keep them until several years after you sell.

Do ESPP shares affect your tax code?

They can, because the discount raises your taxable pay in the month of purchase. A large purchase can tip a high earner into the allowance taper or the child benefit charge. The code often catches up a year late.

Our guide to PAYE coding notices covers the code.

Check the code after your first purchase.

Can you contribute through salary sacrifice?

Almost never, because contributions come from taxed pay rather than before tax. That is a key difference from a pension, and it means you have already paid tax on the money you used to buy. Only the discount is new income.

Our guide to salary sacrifice for US citizens covers the arrangements.

Contributions themselves give no relief in either country.

What if the share price falls?

You still pay tax on the discount measured at purchase, even if the shares are worth less by the time you sell. The later fall is a capital loss, and losses offset gains rather than the income already charged. People get caught by this regularly.

Our guide to the US-UK tax treaty covers a related point.

A lookback makes the gap between price and tax wider.

Do dividends complicate things?

Only mildly. Dividends on the shares are taxed in both countries with the usual credit, exactly as any other American holding would be. They are a separate stream from the discount and need no base cost adjustment.

Our guide to US withholding tax for UK investors covers the rates.

Reinvested dividends still count as received.

Does the net investment income tax apply?

To the gain on sale, potentially, though not to the discount itself. Compensation income sits outside that charge while investment gains do not. No foreign tax credit relieves it, which makes it a genuine extra cost.

Our guide to the net investment income tax covers the surcharge.

It only bites above the income thresholds.

Does a US employer handle the UK side?

Sometimes badly, and that is worth knowing early. A plan administered from America may report nothing useful to British payroll, leaving the employer to catch up months later. Ask your payroll team how they treat it.

Our guide to shadow payroll arrangements covers dual payrolls.

An unreported purchase surfaces as an underpayment later.

What about a global plan with many countries?

The plan rules are the same everywhere and the tax treatment is not. Colleagues in other countries will describe outcomes that simply do not apply to you. Take the British and American answer rather than the office consensus.

Our guide to a US secondment and tax covers international moves.

Plan documents rarely mention any country's tax.

Should you fund the plan to the maximum?

The discount argues yes and the concentration risk argues no. Holding a large share of your savings in your employer's stock is a separate problem from tax. Many people buy the maximum and sell immediately for exactly that reason.

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

Selling at once removes both problems together.

How much work is this each year?

An hour, if you keep the confirmations. First you list each purchase, then you note the British charge, and finally you convert both. In short, it is bookkeeping rather than judgement, so the time goes on finding papers.

Our guide to registering for Self Assessment covers the British return.

Set up a folder the month you join the plan.

What if you joined years ago?

Then the base cost on every past sale is probably wrong. But only the open years can be amended, so there is a limit to what you can recover. Still, fixing the position going forward costs nothing.

Our guide to amending a US return covers corrections.

Three years back is usually the practical limit.

Is there a British approved alternative?

Yes, and some employers run one alongside. A save as you earn scheme or a share incentive plan gives British relief that an American plan cannot. However, the IRS ignores those reliefs entirely, so the mirror problem appears.

Our guide to EMI options for Americans covers another British scheme.

No scheme is efficient in both countries at once.

Who should you ask inside the company?

The share plan administrator for the documents, and payroll for the British treatment. Neither will give tax advice, and both hold figures you need. Ask for a transaction history and a copy of the plan rules in writing.

Our guide to choosing a US-UK tax accountant covers the advice side.

Keep whatever they send with that year's tax papers, because nobody will reissue it later.

How to handle ESPP shares

1. Find out whether your plan is qualified or not.
2. Expect British payroll to tax the discount at purchase.
3. Record the sterling figure taxed and the date.
4. Convert it at the rate on that purchase date.
5. Add that amount to your American base cost.
6. Decide whether to sell at once to keep the credit usable.
7. Check whether you agreed to bear the employer charge.
8. Keep purchase confirmations until long after the sale.

Mistakes and penalties we see with ESPP shares

The first is using the broker's base cost unchanged, which taxes the discount a second time on sale.

The second is holding for the American holding periods and stranding the British tax with no credit left to claim.

The third is treating the discount as a capital gain, when both countries treat it as pay.

The fourth is ignoring the employer charge transfer buried in the plan paperwork.

How US UK Tax Accountants helps

We rebuild the American base cost from the British payroll figures, because the broker statement is wrong on almost every plan we see.

Then we work out whether selling at once beats holding. Our US federal returns service covers the filing.

If you have been buying through a plan for years, get in touch before the next sale.

Last reviewed 30 October 2026. This article is general information and not personal tax advice, and plan terms vary.