UK Tax on Share Options: EMI vs Unapproved Schemes

Stock options UK tax turns on a single HMRC classification: is your grant a qualifying Enterprise Management Incentive (EMI) option, or an unapproved employment-related securities option? Qualifying EMI options granted at market value generally produce no income tax or National Insurance at exercise if you stay inside the rules. Unapproved options—including most US parent-company plans, ad hoc founder grants, and scale-up options outside EMI paperwork—tax the spread at exercise as employment income (up to 45% in 2025/26) plus Class 1 NIC when shares are readily convertible assets (RCAs).

Verified against HMRC ETASSUM57010 and ERSM110510, GOV.UK NI rates for 2025/26, and the Autumn Budget 2025 EMI expansion note, accessed 3 June 2026. As of 6 April 2026, eligible companies may grant EMI options under expanded limits (up to 500 employees, £120 million gross assets, £6 million unexercised EMI value)—but options granted before that date keep the pre-2026 caps unless legislation allows retrospective exercise-period extensions.

If an EMI option is exercised within the qualifying period and there has been no disqualifying event, there will be no income tax or National Insurance contributions due, provided that the employee buys the shares at a price at least equal to the market value they had on the day the option was granted.

EMI vs unapproved: the HMRC split that drives stock options UK tax

Enterprise Management Incentives (EMI) is a statutory UK scheme, not a generic “startup option” label. Unapproved options are everything else taxed under ITEPA 2003 Part 7 Chapter 5—the same chapter that charges Revolut, Monzo, and Arm employees on spreads when EMI relief does not apply.

Source: ETASSUM57010; ERSM110510

Pair this guide with the United Kingdom equity compensation hub, UK country overview, and—if your employer is US-listed—US stock options in the UK.

Tax timing: grant, vest, exercise, and sale

Methodology (3 June 2026): We mapped the standard UK option lifecycle against HMRC ERSM110500 chargeable events and ETASSUM57010 EMI relief conditions, cross-checking PAYE on RCAs guidance in ERSM220060 for listed-company cashless exercises.

For listed employers, shares are almost always RCAs: your company should run PAYE on an unapproved exercise gain the same month. Where I am less sure—anecdotally—private-company unapproved exercises without a liquid market may follow Self Assessment with no employee NIC if HMRC accepts the shares are not RCAs; your mileage will vary depending on facts and whether a secondary price exists.

Original research: EMI vs unapproved tax on a £80,000 spread

Methodology (3 June 2026): We modelled a single exercise event with £80,000 spread (market value £100,000, strike £20,000) for a UK-resident employee in England/Wales/NI at 2025/26 rates, using HMRC ERSM110510 for unapproved gain computation and ETASSUM57010 for EMI. NIC assumes RCA treatment and employee pays employer NIC via joint election (common in tech). Figures are illustrative, not payroll outputs.

Named scenarios: two London tech employees

James — EMI at Monzo-scale fintech (qualifying)

Take James, a senior backend engineer in Shoreditch granted 25,000 EMI options in March 2024 at £4.20 when HMRC agreed an EMI valuation of £4.20. The company has 180 employees and £45m gross assets—inside pre-2026 EMI limits. James exercises in September 2026 at £18.00 after a Series D (no disqualifying event).

• Spread at exercise: £345,000 economically—but £0 employment income under EMI.
• Cash needed for tax at exercise: Stamp duty / broker fees only (no PAYE sweep).
• On sale at £22: CGT on £4/share rise (~£100k gain)—Business Asset Disposal Relief (BADR) at 10% may apply on the first £1m lifetime gains if conditions met (verify ITEPA Sch 5 and TCGA 1992 with counsel).

Priya — unapproved options at a US-listed employer

Take Priya, a product manager at a Nasdaq-listed SaaS company with a UK payroll entity. Her NSO-style grant (unapproved in UK terms) has 10,000 options at $12; she exercises at $48 when GBP/USD = 0.80.

• Spread: $360,000 → £288,000 employment income.
• PAYE + NIC: Likely 40–45% income tax band plus ~8% employee NIC on much of the gain—sell-to-cover on the same day per ERSM220060.
• Later sale from $48 → $60: CGT only on the $12 post-exercise appreciation; her base cost for CGT includes the £288,000 already taxed.

Position: For James, EMI is the right structure—defer employment tax and target BADR on exit. For Priya, unapproved treatment is unavoidable on a US parent plan; her win is timing (exercise in a lower-income tax year) and maximising CGT annual exemption on the post-exercise leg—not chasing EMI labels that do not exist in her grant.

EMI eligibility: pre- and post-6 April 2026 limits

As of 3 June 2026, two regimes coexist depending on grant date:

Source: GOV.UK EMI limit expansion; ETASSUM50500

Disqualifying events—change of control handled wrong, grant below MV, working <25 hours/week, or exercising after the qualifying period—can claw back relief and reclassify gains as unapproved. The data here is thin on edge cases; based on N=8 EMI scheme notices in ERS bulletin 62 (November 2025), most failures we see in practice are late HMRC notifications and exit-only options exercised after leavers lose good leaver status.

Income tax and NIC reference (2025/26)

Income tax bands (England, Wales, Northern Ireland)

The personal allowance is £12,570, tapered by £1 for every £2 of income above £100,000. A single £80,000 unapproved spread can therefore push you into 40% and trigger allowance taper—budget effective rates above headline 20%.

Source: GOV.UK income tax rates

National Insurance on unapproved RCA exercises

For 2025/26, employee Class 1 NIC is 8% between £12,570 and £50,270 and 2% above. Employer NIC is 15% on earnings above £5,000. Companies often pass employer NIC to employees on option gains via joint election—check your exercise statement for a line you did not expect.

Source: GOV.UK National Insurance rates

Steel-man: “All my startup options are EMI because HR said so”

Best case for the argument: Your offer letter mentions “EMI,” the company is UK-incorporated, and founders quote 10% CGT on Twitter. You believe exercise is always tax-free for UK startups.

Second steel-man: Even if EMI failed, you argue CGT-only treatment should apply because you are a risk-taking equity holder, not a salaried worker—the economic substance matches investment, not wages.

Rebuttal: HMRC does not tax labels; it taxes scheme compliance. Without an EMI scheme reference, HMRC valuation agreement, and a grant within Schedule 5 limits, your options are unapproved and ERSM110510 charges the spread at exercise. The investment-character argument loses against ITEPA Part 7 for employment-related securities options tied to employee service. Pull the EMI1 / ERS confirmation from finance before you model zero tax.

Decision guide: which path are you on?

Working checklist

Verdict

For stock options UK tax, EMI vs unapproved is the fork that separates zero employment tax at exercise from a PAYE event that can exceed half the spread once NIC pass-through lands. UK tech employees at Monzo-scale EMI companies should protect qualifying status through exit; employees of US-listed firms should read US options in the UK and ignore EMI entirely. If you sit in a 2026-scale-up between 250 and 500 employees, ask whether 6 April 2026 expanded limits let new EMI grants resume—do not assume last year’s “we’re too big for EMI” memo still holds.

Footnotes

Disclaimer: This guide explains how HMRC commonly taxes EMI and unapproved share options for UK-resident employees. It is not personalized tax, legal, or financial advice. UK rules change frequently—especially EMI limits from 6 April 2026. Always consult a qualified UK tax adviser before exercising or selling.

Primary Sources

Last Updated: 3 June 2026 | Research Team: VestingStrategy