ESPPs in the UK: Tax, when to sell and what to do with your shares

By Philip Dragoumis

In the UK, the discount you receive on shares through an Employee Stock Purchase Plan (ESPP) is usually taxed as employment income when you buy them. Any subsequent growth may then be subject to Capital Gains Tax when you sell.

ESPPs are a popular employee benefit at US technology companies such as Microsoft, Google, Meta and Amazon. They can be an attractive way to build wealth, but the UK tax treatment isn’t always straightforward.

Here is what you need to know about the tax, when to sell and how ESPPs fit into your wider financial plan.

What is an ESPP and how does it work in the UK?

An Employee Stock Purchase Plan allows employees to buy shares in their employer, usually at a discount of up to 15%.

Typically, you contribute a percentage of your salary through payroll over six months. The money comes from your salary after income tax and National Insurance.

At the end of the period, your contributions purchase company shares.

Many plans include a lookback feature, meaning the purchase price is based on the lower share price at the beginning or end of the offering period.

For example, if the shares were worth $100 at the start and $140 six months later, a 15% discount with a lookback could allow you to buy them for $85.

That’s a discount of almost 40% to their current market value.

Most ESPPs offered by US companies are not UK tax-advantaged schemes, unlike Sharesave (SAYE) or Share Incentive Plans (SIPs).

How is an ESPP taxed in the UK?

For most UK employees, ESPP shares are potentially taxed at two stages.

When you buy: The difference between the market value and the discounted price is normally treated as employment income, subject to income tax and usually National Insurance. For listed shares, this is generally collected through PAYE as explained in HMRC’s employment Related Securities Manual

When you sell: Any additional gain above the market value at purchase may be subject to Capital Gains Tax (CGT).

A worked example

Suppose you participate in your employer’s ESPP:

	Amount
Your contributions	£8,500
Market value when purchased	£14,000
Discount subject to income tax	£5,500
Value when eventually sold	£17,000
Potential capital gain	£3,000

If you’re an additional-rate taxpayer, the £5,500 discount could attract income tax at 45% and employee National Insurance at 2%, producing a liability of approximately £2,585.

If you subsequently sell the shares for £17,000, your potential capital gain is £3,000, not £8,500.

Whether CGT is payable depends on your available allowances, other gains and personal circumstances.

Why can it look like you pay tax twice on ESPP shares, and how do you avoid it?

One of the most common ESPP mistakes is using the wrong acquisition cost when calculating Capital Gains Tax.

US brokers such as Morgan Stanley, Fidelity, E*Trade and Schwab may show the discounted price you originally paid rather than the correct UK CGT cost.

Using our example, you paid £8,500 for shares worth £14,000. Because the £5,500 discount was already taxed as employment income, your starting CGT cost is generally £14,000. This treatment is explained in HMRC’s guidance on employment-related securities and Capital Gains Tax.

Using £8,500 instead could mean paying CGT on an amount already taxed as income.

Keep your purchase confirmations, payslips and records of the market value on each purchase date. These are essential when calculating gains for your Self Assessment return.

Where you have multiple purchases, HMRC’s share-matching rules may affect the final calculation.

What does the ESPP deduction on your payslip mean?

The ESPP deduction is normally your contribution towards buying company shares, not an additional tax.

For most US-style ESPPs, contributions come from your salary after tax and National Insurance.

When the shares are purchased, the discount becomes taxable employment income. This may appear as notional share income on your payslip, with the associated tax deducted through payroll.

This explains why some employees see an unexpectedly large tax deduction during an ESPP purchase month.

When should you sell your ESPP shares?

For many employees, selling ESPP shares shortly after purchase is a sensible strategy.

You’ve already benefited from the discount. Selling secures that value and removes the risk of the share price falling.

Of course, the shares could continue rising. But that’s a separate investment decision.

Here’s the question I would ask: If your employer gave you the equivalent amount in cash today, would you use it to buy shares in the company?

If the answer is no, why are you holding them?

This is particularly relevant for senior technology executives who may already receive substantial Restricted Stock Units (RSUs), bonuses and salary from the same employer.

You could end up with a significant proportion of your financial future depending on one company’s performance.

What about Capital Gains Tax?

For the 2026/27 tax year, the CGT annual exemption is £3,000, with rates of 18% and 24% applying to share gains, depending on your taxable income. See HMRCs current Capital Gains Tax rates and allowances.

Two complications are worth remembering.

Share-matching rules: HMRC matches sales against shares acquired on the same day, then acquisitions within the following 30 days, and finally your pooled holdings under Section 104. Regular ESPP purchases and RSU vestings can complicate the calculation. You can find the full explanation in HMRC’s share identification rules 

Currency movements: UK capital gains are calculated in sterling, even when shares are traded in dollars. Exchange rate movements can therefore affect your taxable gain.

ESPP vs RSU: What’s the difference?

ESPPs and Restricted Stock Units are both forms of employee share compensation, but they work differently.

	ESPP	RSU
How you acquire shares	Buy at a discount	Awarded by employer
Do you contribute money?	Yes	No
Income tax usually due	On discount at purchase	On value at vesting
CGT potentially due	On growth after purchase	On growth after vesting

Both can leave you with substantial exposure to your employer’s share price.

For more detail, see our guide to RSUs and how they are taxed in the UK.

Can you move ESPP shares into an ISA or a pension?

Shares purchased through a typical US ESPP cannot normally be transferred directly into an ISA.

Special rules allow qualifying UK SAYE and SIP shares to be transferred within 90 days, but these generally don’t apply to US ESPPs. See HMRC’s guidance on transferring employee shares into an ISA 

The usual alternative is Bed and ISA: selling your shares and reinvesting the proceeds inside an ISA, subject to your available allowance.

The ISA allowance for 2026/27 is £20,000. Selling the shares may trigger CGT, but future gains and income within the ISA are generally tax-free.

Alternatively, you could use the proceeds to make pension contributions and potentially benefit from income tax relief.

However, high earners need to consider the tapered annual allowance, which can significantly restrict tax-efficient pension contributions.

The right approach depends on your overall financial position, existing investments and future plans.

US shares held by a UK resident: What else should you know?

Two additional US tax issues are worth understanding.

US dividend withholding tax: Dividends from US companies are generally subject to withholding tax. Completing a W-8BEN form normally reduces the US rate from 30% to 15% for eligible UK residents under the UK-US tax treaty. UK dividend tax may also apply, potentially with credit for US tax paid.

US estate tax: Shares in US-incorporated companies can create potential US estate tax exposure for non-US citizens. The US filing threshold for non US citizens can be as low as $60,000 of US-situated assets, although the UK-US estate tax treaty can provide substantial relief.

If you hold significant US shares, specialist cross-border tax advice may be worthwhile.

What happens to your ESPP when you leave your job?

When you leave your employer, your ESPP contributions normally stop.

Money contributed but not yet used to purchase shares is usually refunded, depending on your plan rules.

Shares you’ve already purchased generally remain yours. You can normally continue holding or selling them, subject to any restrictions.

Check your employer’s plan documentation, particularly if you’re leaving during an offering period or moving abroad.

When should you get financial advice about your ESPP?

ESPPs can be an excellent employee benefit. But the bigger question isn’t necessarily how much tax you pay. It’s what you do with the shares afterwards.

For senior executives receiving significant RSUs, bonuses and other equity compensation, it’s surprisingly easy to accumulate a substantial investment in one company without consciously deciding to do so.

At Thera Wealth Management, we help senior executives and professionals organise their company shares, pensions and investments around their wider financial goals.

If you have substantial ESPP or RSU holdings and would like to understand how they fit into your financial plan, arrange an initial conversation with Thera Wealth Management.

Frequently asked questions about ESPPs in the UK

Do I pay tax on ESPP shares in the UK?

Yes. For most UK employees participating in a US-style ESPP, the discount received when purchasing shares is treated as employment income, subject to income tax and usually National Insurance. If the shares subsequently increase in value, Capital Gains Tax may also apply when you sell, depending on your circumstances.

Is the ESPP discount taxed as income?

Yes. The difference between the market value of the shares when purchased and the discounted price you pay is normally taxable employment income. For publicly listed shares, your employer will generally collect income tax and National Insurance through payroll when the shares are acquired.

How do I avoid paying tax twice on my ESPP?

Use the correct acquisition cost when calculating UK Capital Gains Tax. The amount already taxed as employment income generally increases the allowable cost of your shares. US brokerage statements may show only the discounted purchase price, so retain your payslips and purchase records and check the applicable UK share-matching rules.

Should I sell my ESPP shares straight away?

For many employees, selling shortly after purchase makes sense because it secures the value of the discount and reduces exposure to their employer’s share price. Holding may be appropriate in some circumstances, but consider how much of your wealth and future income already depends on the same company.

Can I put my ESPP shares into an ISA?

Shares purchased through a typical US ESPP cannot normally be transferred directly into an ISA. Instead, you can sell them and reinvest the proceeds within your available ISA allowance, potentially triggering Capital Gains Tax. Special direct-transfer rules apply to qualifying UK SAYE and SIP shares, but generally not US ESPPs.

What happens to my ESPP if I leave my job?

You will normally stop contributing to your ESPP when your employment ends. Contributions not yet used to purchase shares are usually refunded, while shares already purchased remain yours. The precise treatment depends on your employer’s plan rules, particularly if you leave during an offering period or move abroad.

This guide is for information purposes and does not constitute financial advice, which should be based on your individual circumstances.

The value of investments and any income from them can fall as well as rise. You may not get back the full amount invested.

HM Revenue and Customs practice and the law relating to taxation are complex and subject to individual circumstances and changes which cannot be foreseen

The favourable tax treatment of ISAs may be subject to changes in legislation in the future.

Levels and bases of, and reliefs from, taxation are subject to change and their value will depend upon personal circumstances. Taxation and pension legislation may change in the future.