Specialist US UK Tax Services: EMI Options on a US Return

A qualifying Enterprise Management Incentive option is tax-advantaged in the UK and entirely ordinary in the United States. HMRC normally charges nothing at grant or exercise and waits for the sale; the IRS treats the same option as a non-qualified option under IRC section 83 and taxes the spread at exercise as compensation, in the year of exercise, even where no UK tax is due.

That single divergence — one taxing point at exercise, another at sale — is the reason so many American founders and senior hires at UK startups discover an unreported US income event years after the fact. This guide sets out the reporting mechanics: what goes on the US return, what HMRC does and does not charge, how the foreign tax credit timing mismatch arises, and how to rebuild exercise records for US years that were never filed. Our Specialist US UK tax services exist for precisely this reconstruction work, and Jungle Tax prepares these returns for founders and executives on both sides of the Atlantic every week.

Why do the US and UK tax an EMI option at different moments?

The two regimes are not disagreeing about the amount. They are disagreeing about the event.

Under UK law, an option granted under a qualifying EMI arrangement at a price not less than the actual market value of the shares at grant produces no income tax and no National Insurance charge on grant, and none on exercise. The entire economic gain — from the exercise price through to the eventual sale proceeds — is deferred into the capital gains regime and taxed only when the shares are disposed of. Where the conditions for Business Asset Disposal Relief are satisfied, the EMI holding period generally runs from the date of grant rather than the date of exercise, which is a deliberate structural concession.

Under US law, none of that exists. The Internal Revenue Code recognises exactly two categories of employee option: statutory options (incentive stock options and employee stock purchase plan options, which must satisfy detailed Code requirements including being granted by a corporation under a plan approved by shareholders) and everything else. An EMI option is "everything else". It is a non-statutory — non-qualified — option governed by section 83 and the regulations under it.

For a non-statutory option without a readily ascertainable fair market value at grant, which describes essentially every private UK startup option, section 83 produces this sequence:

• Grant: no US income event. The option itself is not treated as property with an ascertainable value.
• Exercise: the US income event. The excess of the fair market value of the shares received over the exercise price paid is compensation income, taxed at ordinary rates in the year of exercise.
• Sale: a capital transaction only. The gain or loss is measured against a basis equal to the exercise price plus the spread already taxed, with a holding period running from exercise.

The UK gives relief at exercise and collects at sale. The US collects at exercise and treats the sale as capital. Nothing in the US-UK income tax treaty converts an EMI option into a US statutory option, and nothing in UK law defers the US charge.

US versus UK treatment of an EMI option, side by side

Stage	UK (HMRC) treatment	US (IRS) treatment
Grant at actual market value	No income tax, no NIC. EMI notification obligation sits with the company.	No income event. Option has no readily ascertainable fair market value.
Vesting	No charge. Vesting is not a UK taxing point for an option.	No charge on the option itself. Vesting matters only for sourcing the eventual spread.
Exercise	Normally no income tax and no NIC on a qualifying option exercised at or above market value at grant.	Taxable. Spread between fair market value and exercise price is ordinary compensation income under section 83.
Exercise after a disqualifying event, more than 90 days later	Income tax (and NIC if the shares are readily convertible assets) on growth from the date of the disqualifying event, plus any original discount.	Identical to any other exercise. The US does not recognise "disqualifying events" — the full spread is income either way.
Restricted shares acquired on exercise	Section 431 election within 14 days fixes the charge by reference to unrestricted market value.	Section 431 has no US effect. The analogous US election is a section 83(b) election, on a different deadline and different facts.
Sale of the shares	Capital gains tax on proceeds less the amount paid (and any amount already charged to income tax). BADR may apply.	Capital gain or loss measured against exercise price plus the previously taxed spread. Holding period runs from exercise.
Currency	Everything computed in sterling.	Everything computed in US dollars at historic rates, lot by lot.

What exactly goes on the US return in the year of exercise?

The character of the income

The spread is compensation for services. It is ordinary income, taxed at the graduated rates that apply to wages, and it is earned income for the purposes of the foreign earned income exclusion to the extent it is attributable to services performed abroad. It is not capital gain and it is not passive income, which matters enormously for the foreign tax credit basket it falls into.

The reporting mechanics

Where a US employer exercises withholding, the spread appears in Box 1 of Form W-2 with a code V entry. A UK startup with no US payroll registration typically issues nothing — no W-2, no Form 1099. The absence of a US information return is the single most common reason the income is omitted. The amount still has to be reported as wages on Form 1040, and where no US employer reported it, it is generally reported as other compensation supported by a statement reconciling the calculation.

Because there is no US withholding, the exercise can create a substantial balance due and an estimated tax exposure in a year in which the taxpayer received no cash at all. This is the classic "dry charge" of a private company exercise, and it is a US problem rather than a UK one, which is why UK advisers routinely miss it.

Payroll taxes

An individual working in the UK and paying Class 1 National Insurance under the US-UK totalization agreement is generally covered by the UK system alone, so US Social Security and Medicare tax should not attach to the same earnings. The certificate of coverage position needs to be documented in the file, not assumed. Where the individual has moved to the US before exercise, the analysis changes and the earnings period matters.

Does a disqualifying event change the US answer?

No. A disqualifying event — the company ceasing to meet the qualifying trade or gross assets conditions, the employee's working time falling below the statutory requirement, a relevant alteration to share capital, or the individual ceasing to be an eligible employee — affects the UK relief only. HMRC's guidance on exercise following a disqualifying event is set out in the Employee Tax Advantaged Share Scheme User Manual, which explains how the charge on a discounted option is computed where exercise happens outside the 90-day window.

The practical consequence for a US citizen is counter-intuitive. A disqualifying event makes the position simpler, not worse, because it brings a UK income tax charge into the same year as the US charge and therefore into the same foreign tax credit year. A clean qualifying exercise, by contrast, produces a US charge with no contemporaneous UK tax at all — the worst credit outcome available.

Relocation is the disqualifying event most frequently encountered in our files: an employee who leaves UK employment, or whose committed working time for the qualifying company falls away, can trigger one without any corporate event occurring. Where that happened years ago and was never picked up, both returns need rebuilding, not just the US one.

Section 431 elections and their US shadow

Where the shares acquired on exercise are restricted securities — and articles of association in UK startups almost always impose leaver provisions, compulsory transfer rights and pre-emption that constitute restrictions — a joint section 431 election may have been signed within 14 days of acquisition. The election disapplies the restricted securities rules so that the acquisition is taxed by reference to unrestricted market value, removing the later charge when the restrictions fall away.

Why the election has no US effect

Section 431 is a provision of UK employment income legislation. It has no bearing on the timing or amount of the US charge. The US analysis of restricted shares runs through section 83(a) and, where elected, section 83(b).

• Section 83(b) applies to a transfer of property subject to a substantial risk of forfeiture and must be filed with the IRS within 30 days of the transfer. For an option holder this ordinarily arises only on an early exercise of unvested options, where shares are actually acquired before vesting.
• Ordinary UK leaver restrictions generally do not amount to a substantial risk of forfeiture for US purposes, so a fully vested exercise produces an immediate section 83(a) charge whatever the UK restricted securities position is.
• A section 431 election signed without a corresponding US analysis can leave the two systems taxing different amounts in different years — the UK by reference to unrestricted market value at acquisition, the US by reference to fair market value on the exercise date.

For catch-up work the practical point is documentary. The signed section 431 election is the best contemporaneous evidence of the valuation the company adopted at exercise, and it is often the only surviving record of the unrestricted market value used. Ask for it before reconstructing anything.

The foreign tax credit timing mismatch

This is where an otherwise competent US return goes wrong. The US taxes the spread in year one. The UK taxes the gain in year five, when the shares are sold. The foreign tax credit is not a running balance that can be applied whenever convenient; it is computed year by year, by income category, and it requires foreign tax paid or accrued in respect of foreign-source income in the same category and, subject to carryover rules, the same year.

Sourcing the compensation

The spread is sourced by reference to where the services were performed over the period the option related to — generally grant to vest — on a workday basis. An American who was in London throughout that period will treat the whole spread as foreign-source general category income. Someone who moved mid-vesting apportions it. Getting this wrong in either direction destroys the credit computation: US-source compensation supports no credit at all, and over-claiming foreign source invites adjustment.

Why the credit often cannot be used

In the year of a qualifying EMI exercise there is usually no UK tax on the same income, because the UK relief is exactly what makes EMI attractive. The taxpayer therefore has foreign-source general category income and no corresponding foreign tax. If there are other UK taxes in the same year and the same category — PAYE on salary and bonus, for instance — the limitation fraction improves, which is why the spread is best analysed alongside the whole year's employment income rather than in isolation.

Carryback, carryforward and the sale year

Excess general category credits may be carried back one year and forward ten. The sale year, in which UK capital gains tax finally arises, sits in a different income category and cannot simply absorb the compensation-year shortfall. Where the UK charges capital gains tax on a gain the US also taxes, relief usually has to be found through the treaty's relief-from-double-taxation article and its re-sourcing rules rather than through ordinary section 904 mechanics. The IRS explains the basic framework in its foreign tax credit guidance, with the detailed limitation and carryover rules in Publication 514; the credit itself is claimed on Form 1116.

The honest conclusion, which generalist pages avoid, is that the UK relief and the US charge frequently do not net out. Reporting the position correctly is still the objective; pretending the credit fixes it is how amended returns and enquiries begin.

Dollar basis tracking, lot by lot

Every exercise creates a separate tax lot with its own US dollar basis and its own holding period. Reconstructing them later is mechanical but unforgiving.

• Exercise price paid. Translated to dollars at the spot rate on the date of payment, not the date of grant and not an annual average.
• Spread taxed as compensation. Fair market value on the exercise date less the exercise price, translated at the spot rate on the exercise date.
• Resulting basis. The sum of the two, in dollars, fixed permanently for that lot.
• Holding period. Begins the day after exercise for US purposes, regardless of the UK rule that runs the EMI holding period from grant.
• Any UK income tax borne. Recorded separately, because it feeds the credit computation, not the basis.

Sterling-denominated shares also create a currency element the UK ignores entirely. A US person sells a UK company's shares for sterling and computes gain in dollars; movement in the exchange rate between exercise and sale is embedded in that gain. Two taxpayers with identical sterling outcomes can have materially different US results.

Where several exercises have occurred, identify shares by lot at disposal and keep the supporting evidence with the return. Averaging lots, or using the sale-date rate for everything, is the error we correct most often when we take over a file. Our US tax return preparation team rebuilds these schedules from primary documents rather than from a broker statement that does not exist.

What else travels with the shares?

Acquiring shares in a UK company can switch on reporting that has nothing to do with the option itself:

• Form 8938. Directly held stock in a foreign corporation is a specified foreign financial asset. Thresholds for taxpayers living abroad are higher than domestic ones, but a founder's stake will often clear them on its own. Unvested options and the shares themselves are analysed separately.
• Form 5471. Where ownership reaches the statutory thresholds — directly, indirectly or by attribution, including option attribution — an information return may be required for the UK company, with substantial penalties for omission regardless of whether tax is due.
• FBAR. Shares held directly in certificated or registered form are not a financial account and are not FBAR-reportable. Shares or cash held through a nominee, platform or brokerage account can be. The distinction is frequently reversed in DIY filings.
• UK employment-related securities reporting. An employer obligation rather than the individual's, but the company's annual return is a reliable source of exercise dates and valuations when the employee's own records have gone.

How do you rebuild EMI exercises for unfiled US years?

Most of the people who reach us are not asking an academic question. They exercised three or five years ago, filed nothing in the US, and now face a liquidity event or a bank's request for tax returns. The reconstruction runs in a set order.

1. Assemble the option documents. Grant agreement and EMI option certificate, the exercise notice, any section 431 election, the company's articles at the date of exercise, and the board minute approving the valuation.
2. Establish fair market value at each exercise date. The HMRC-agreed valuation used for EMI purposes is the natural starting point and is usually defensible for US purposes, but it must be identified as a valuation rather than assumed.
3. Fix the exchange rates. Spot rates for each exercise date and each payment date, documented with their source.
4. Determine residence and workday history. For sourcing the spread across the grant-to-vest period, and to confirm which UK taxes are available as credits in each year.
5. Rebuild each affected US year. Compensation income, foreign tax credit or exclusion position, information returns, and estimated tax and interest exposure.
6. Check the UK side has not moved. A disqualifying event, a leaver exercise or an unsigned section 431 election may mean a UK charge was also missed, in which case the UK position is corrected too.
7. Choose the compliance route. Where the failure to file was non-willful, the IRS Streamlined Foreign Offshore Procedures remain the standard route for a US person resident abroad, requiring the delinquent returns, the associated FBARs and a signed non-willfulness certification.

Our IRS streamlined filing specialists handle the certification narrative and the return package together, because the two have to tell the same story. A streamlined submission that reports the exercise but cannot explain how the valuation and exchange rate were derived invites exactly the follow-up it was meant to avoid.

Errors we correct most often

• Treating an EMI option as the US equivalent of an incentive stock option and reporting nothing until sale.
• Reporting the spread in the year of sale rather than the year of exercise, which misstates two years at once.
• Claiming a foreign tax credit in the exercise year for UK capital gains tax that will not be paid for several more years.
• Using the sale-date exchange rate to compute basis, or converting the whole position at a single annual average rate.
• Assuming a section 431 election produced a US election, or that a US section 83(b) election was made because a UK form was signed.
• Omitting Form 8938 or Form 5471 because no tax was due on the shares in the year of acquisition.
• Filing amended returns quietly where a streamlined submission was the appropriate route, or the reverse.

Where the two systems actually meet

It helps to hold one idea clearly. The UK is not giving relief the US refuses to honour; the two countries are taxing different events, and a treaty that allocates taxing rights between them cannot re-time a domestic charge that neither country considers to be on the same income in the same year. That is why a cross-border file needs both calculations run together from the start, and why a UK-only adviser's clean EMI outcome and a US-only preparer's clean section 83 return can both be right and still produce a wrong overall result.

For founders holding material stakes, the reconstruction work sits alongside the wider high net worth compliance position and the UK filings handled by our UK tax team. Related reading is collected in our guides library.

Speak to us in confidence

If you hold EMI options, have exercised them, or are approaching a liquidity event with US filings outstanding, the position is fixable — and it is far easier to fix before a buyer's diligence team asks the question. We will review the option documents, model the US and UK charges across the relevant years, and tell you plainly what needs to be filed and in what order. To start, contact our cross-border team for a confidential consultation with a specialist who prepares both returns.