# ESOS Meaning: Employee Share Option Schemes Explained

Published: 2026-01-22
Author: Warren Team
URL: https://www.heywarren.com/blog/esos

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ESOS stands for Employee Share Option Scheme — a form of equity compensation that grants employees the right to purchase company shares at a predetermined price (the exercise price) at some future point, typically after a vesting period. ESOS is widely used in the UK, Singapore, and other Commonwealth markets as both a recruitment and retention tool, and as a way to align employee incentives with long-term shareholder value creation. Understanding how ESOS works is essential for employees evaluating compensation packages and for investors assessing the dilution impact on existing shareholders.

## What Is an Employee Share Option Scheme?

An ESOS grants an employee an **option** — not an obligation — to buy a set number of company shares at a fixed price on or after a specified date. The value of the option derives from the difference between the current market price and the exercise price.

**Key components**:
- **Grant date**: When the options are awarded
- **Exercise price ([strike price](/blog/strike-prices))**: The fixed price at which the employee can buy shares — typically set at market price on the grant date
- **Vesting period**: The time the employee must remain employed before options can be exercised (commonly 3–4 years, often with a one-year cliff)
- **Expiry date**: Options expire if not exercised within a set window (often 10 years from grant)

**Simple example**:
- Grant date: shares worth £10
- Exercise price: £10
- Shares after 3 years: £25
- Profit on exercise: £25 − £10 = £15 per share × 10,000 options = **£150,000 gain**

## How ESOS Vesting Works

Most ESOS plans use **time-based vesting** with a cliff:

![A four-year cliff vesting schedule showing how options unlock 25% per year after the one-year cliff.](data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20viewBox%3D%220%200%20800%20149%22%20width%3D%22800%22%20height%3D%22149%22%20role%3D%22img%22%3E%3Ctitle%3ETimeline%3C%2Ftitle%3E%3Crect%20width%3D%22100%25%22%20height%3D%22100%25%22%20fill%3D%22%23f8fafc%22%2F%3E%3Cline%20x1%3D%22120%22%20y1%3D%2255%22%20x2%3D%22680%22%20y2%3D%2255%22%20stroke%3D%22%23cbd5e1%22%20stroke-width%3D%223%22%2F%3E%3Ccircle%20cx%3D%22120%22%20cy%3D%2255%22%20r%3D%2224%22%20fill%3D%22white%22%20stroke%3D%22%23cbd5e1%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22120%22%20y%3D%2260%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2215%22%20font-weight%3D%22700%22%20fill%3D%22%230f172a%22%3E1%3C%2Ftext%3E%3Ctext%20x%3D%22120%22%20y%3D%22101%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2212%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3EGrant%20Date%3C%2Ftext%3E%3Ctext%20x%3D%22120%22%20y%3D%22119%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3E0%25%20vested%3C%2Ftext%3E%3Ccircle%20cx%3D%22260%22%20cy%3D%2255%22%20r%3D%2224%22%20fill%3D%22%232563eb%22%20stroke%3D%22%232563eb%22%20stroke-width%3D%223%22%2F%3E%3Ctext%20x%3D%22260%22%20y%3D%2260%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2215%22%20font-weight%3D%22700%22%20fill%3D%22white%22%3E2%3C%2Ftext%3E%3Ctext%20x%3D%22260%22%20y%3D%22101%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2212%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3EYear%201%20Cliff%3C%2Ftext%3E%3Ctext%20x%3D%22260%22%20y%3D%22119%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3E25%25%20vested%3C%2Ftext%3E%3Ccircle%20cx%3D%22400%22%20cy%3D%2255%22%20r%3D%2224%22%20fill%3D%22white%22%20stroke%3D%22%23cbd5e1%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22400%22%20y%3D%2260%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2215%22%20font-weight%3D%22700%22%20fill%3D%22%230f172a%22%3E3%3C%2Ftext%3E%3Ctext%20x%3D%22400%22%20y%3D%22101%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2212%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3EYear%202%3C%2Ftext%3E%3Ctext%20x%3D%22400%22%20y%3D%22119%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3E50%25%20vested%3C%2Ftext%3E%3Ccircle%20cx%3D%22540%22%20cy%3D%2255%22%20r%3D%2224%22%20fill%3D%22white%22%20stroke%3D%22%23cbd5e1%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22540%22%20y%3D%2260%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2215%22%20font-weight%3D%22700%22%20fill%3D%22%230f172a%22%3E4%3C%2Ftext%3E%3Ctext%20x%3D%22540%22%20y%3D%22101%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2212%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3EYear%203%3C%2Ftext%3E%3Ctext%20x%3D%22540%22%20y%3D%22119%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3E75%25%20vested%3C%2Ftext%3E%3Ccircle%20cx%3D%22680%22%20cy%3D%2255%22%20r%3D%2224%22%20fill%3D%22white%22%20stroke%3D%22%23cbd5e1%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22680%22%20y%3D%2260%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2215%22%20font-weight%3D%22700%22%20fill%3D%22%230f172a%22%3E5%3C%2Ftext%3E%3Ctext%20x%3D%22680%22%20y%3D%22101%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2212%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3EYear%204%3C%2Ftext%3E%3Ctext%20x%3D%22680%22%20y%3D%22119%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3E100%25%20vested%3C%2Ftext%3E%3C%2Fsvg%3E)

*A four-year cliff vesting schedule showing how options unlock 25% per year after the one-year cliff.*

| Year | Shares Vested | Cumulative Vested |
|---|---|---|
| Year 0 (grant) | 0% | 0% |
| Year 1 (cliff) | 25% | 25% |
| Year 2 | 25% | 50% |
| Year 3 | 25% | 75% |
| Year 4 | 25% | 100% |

The cliff means an employee who leaves before year 1 receives nothing. After the cliff, vesting typically occurs monthly or quarterly. **Performance-based vesting** is also common in senior executive schemes — options only vest if specific financial or operational targets are met (revenue growth, EPS thresholds, TSR vs peers).

## ESOS in Different Markets

### UK: HMRC-Approved Schemes

The UK has several tax-advantaged ESOS structures:

**Enterprise Management Incentive (EMI)**: For smaller companies (under £30m gross assets). Gains on exercise of EMI options are taxed at Capital Gains Tax rates (10–20%) rather than income tax rates (up to 45%). Maximum £250,000 per employee.

**Company Share Option Plan (CSOP)**: For larger companies. Up to £60,000 of options per employee (from April 2023, doubled from prior limit). Gains on exercise are CGT-taxed if the plan meets HMRC requirements.

**Unapproved options**: No HMRC approval, no tax advantages. Exercise gain is income-taxed. Used when employees exceed tax-advantaged limits.

### Singapore

Singapore ESOS grants are generally taxed on the difference between market value and exercise price at the time of exercise — at ordinary income tax rates. Singapore's flat rate structure (max 22%) makes ESOS relatively attractive compared to higher-tax jurisdictions.

### US Equivalent: Incentive Stock Options (ISOs) and NSOs

While not called ESOS in the US, ISOs (Incentive Stock Options) are the direct equivalent — with favorable AMT treatment on the spread if shares are held after exercise. NSOs (Non-Qualified Stock Options) are taxed as ordinary income on exercise.

## ESOS vs. RSUs: Key Differences

Both are forms of equity compensation, but the structures differ materially:

![Options offer higher upside leverage but carry more complexity and risk of zero value; RSUs are simpler with guaranteed value.](data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20viewBox%3D%220%200%20720%20480%22%20width%3D%22720%22%20height%3D%22480%22%20role%3D%22img%22%3E%3Ctitle%3EQuadrant%20matrix%3C%2Ftitle%3E%3Crect%20width%3D%22100%25%22%20height%3D%22100%25%22%20fill%3D%22%23f8fafc%22%2F%3E%3Crect%20x%3D%2290%22%20y%3D%2225%22%20width%3D%22300%22%20height%3D%22190%22%20fill%3D%22%23dbeafe%22%2F%3E%3Crect%20x%3D%22390%22%20y%3D%2225%22%20width%3D%22300%22%20height%3D%22190%22%20fill%3D%22%23d1fae5%22%2F%3E%3Crect%20x%3D%2290%22%20y%3D%22215%22%20width%3D%22300%22%20height%3D%22190%22%20fill%3D%22%23ffedd5%22%2F%3E%3Crect%20x%3D%22390%22%20y%3D%22215%22%20width%3D%22300%22%20height%3D%22190%22%20fill%3D%22%23ede9fe%22%2F%3E%3Cline%20x1%3D%2290%22%20y1%3D%22215%22%20x2%3D%22690%22%20y2%3D%22215%22%20stroke%3D%22%2364748b%22%20stroke-width%3D%222%22%2F%3E%3Cline%20x1%3D%22390%22%20y1%3D%2225%22%20x2%3D%22390%22%20y2%3D%22405%22%20stroke%3D%22%2364748b%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22240%22%20y%3D%22100%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2213%22%20font-weight%3D%22700%22%20fill%3D%22%230f172a%22%3ERSUs%3C%2Ftext%3E%3Ctext%20x%3D%22240%22%20y%3D%22120%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3E%E2%80%A2%20Free%20to%20receive%3C%2Ftext%3E%3Ctext%20x%3D%22240%22%20y%3D%22136%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3E%E2%80%A2%20Always%20has%20value%3C%2Ftext%3E%3Ctext%20x%3D%22540%22%20y%3D%22100%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2213%22%20font-weight%3D%22700%22%20fill%3D%22%230f172a%22%3EESOS%2FOptions%3C%2Ftext%3E%3Ctext%20x%3D%22540%22%20y%3D%22120%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3E%E2%80%A2%20Leveraged%20gains%3C%2Ftext%3E%3Ctext%20x%3D%22540%22%20y%3D%22136%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3E%E2%80%A2%20Worthless%20if%20OTM%3C%2Ftext%3E%3Ctext%20x%3D%22240%22%20y%3D%22290%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2213%22%20font-weight%3D%22700%22%20fill%3D%22%230f172a%22%3ESalary%3C%2Ftext%3E%3Ctext%20x%3D%22240%22%20y%3D%22310%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3E%E2%80%A2%20Fixed%20pay%3C%2Ftext%3E%3Ctext%20x%3D%22240%22%20y%3D%22326%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3E%E2%80%A2%20No%20equity%20risk%3C%2Ftext%3E%3Ctext%20x%3D%22540%22%20y%3D%22290%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2213%22%20font-weight%3D%22700%22%20fill%3D%22%230f172a%22%3EWarrants%3C%2Ftext%3E%3Ctext%20x%3D%22540%22%20y%3D%22310%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3E%E2%80%A2%20Speculative%3C%2Ftext%3E%3Ctext%20x%3D%22540%22%20y%3D%22326%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3E%E2%80%A2%20High%20strike%20risk%3C%2Ftext%3E%3Ctext%20x%3D%2290%22%20y%3D%22425%22%20text-anchor%3D%22start%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2211%22%20fill%3D%22%2364748b%22%3ELow%20Upside%3C%2Ftext%3E%3Ctext%20x%3D%22690%22%20y%3D%22425%22%20text-anchor%3D%22end%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2211%22%20fill%3D%22%2364748b%22%3EHigh%20Upside%3C%2Ftext%3E%3Ctext%20x%3D%22390%22%20y%3D%22453%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2212%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3EUpside%20Potential%3C%2Ftext%3E%3Ctext%20x%3D%2280%22%20y%3D%2237%22%20text-anchor%3D%22end%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2211%22%20fill%3D%22%2364748b%22%3EHigh%20Risk%3C%2Ftext%3E%3Ctext%20x%3D%2280%22%20y%3D%22405%22%20text-anchor%3D%22end%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2211%22%20fill%3D%22%2364748b%22%3ELow%20Risk%3C%2Ftext%3E%3Ctext%20x%3D%2235%22%20y%3D%22215%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2212%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%20transform%3D%22rotate%28-90%2035%20215%29%22%3ERisk%20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*Options offer higher upside leverage but carry more complexity and risk of zero value; RSUs are simpler with guaranteed value.*

| Feature | ESOS / Options | RSUs |
|---|---|---|
| Cost to employee | Must pay exercise price | Free — shares are awarded |
| Value if price stays flat | $0 (worthless) | Full share value |
| Upside | Leveraged (options amplify gains) | Linear (mirrors share price) |
| Tax event | On exercise (typically) | On vesting |
| Complexity | Higher — requires exercise decision | Lower |

Options have more upside leverage but are worthless if the share price doesn't exceed the exercise price. RSUs always have value as long as the company does. See our guide on [restricted stock units](/blog/restricted-stock-units) for a full comparison.

## Dilution Impact on Existing Shareholders

From an investor perspective, ESOS creates **dilution**: when employees exercise options, new shares are issued, increasing the total share count and diluting existing shareholders' percentage ownership.

![In-the-money options worth 10 million shares expand the diluted share count by ~9% over the basic count.](data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20viewBox%3D%220%200%20800%20210%22%20width%3D%22800%22%20height%3D%22210%22%20role%3D%22img%22%3E%3Ctitle%3EComparison%3C%2Ftitle%3E%3Crect%20width%3D%22100%25%22%20height%3D%22100%25%22%20fill%3D%22%23f8fafc%22%2F%3E%3Ctext%20x%3D%22230%22%20y%3D%2257.5%22%20text-anchor%3D%22end%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2214%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3EBasic%20Shares%3C%2Ftext%3E%3Crect%20x%3D%22240%22%20y%3D%2225%22%20width%3D%22409.09090909090907%22%20height%3D%2255%22%20rx%3D%226%22%20fill%3D%22%232563eb%22%2F%3E%3Ctext%20x%3D%22661.090909090909%22%20y%3D%2257.5%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2214%22%20font-weight%3D%22700%22%20fill%3D%22%232563eb%22%3EM100%3C%2Ftext%3E%3Ctext%20x%3D%22230%22%20y%3D%22152.5%22%20text-anchor%3D%22end%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2214%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3EDiluted%20Shares%3C%2Ftext%3E%3Crect%20x%3D%22240%22%20y%3D%22120%22%20width%3D%22450%22%20height%3D%2255%22%20rx%3D%226%22%20fill%3D%22%237c3aed%22%2F%3E%3Ctext%20x%3D%22702%22%20y%3D%22152.5%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2214%22%20font-weight%3D%22700%22%20fill%3D%22%237c3aed%22%3EM110%3C%2Ftext%3E%3C%2Fsvg%3E)

*In-the-money options worth 10 million shares expand the diluted share count by ~9% over the basic count.*

**Diluted EPS** ([earnings per share](/blog/calculation-of-earning-per-share)) accounts for all outstanding options using the treasury stock method — it shows what EPS would be if all in-the-money options were exercised. Investors should always use diluted EPS, not basic EPS, when valuing companies with significant ESOS programs.

**Dilution example**:
- Current [shares outstanding](/blog/outstanding-stocks-definition): 100 million
- In-the-money options outstanding: 10 million
- Diluted share count: ~110 million (depending on treasury stock method)
- Dilution: ~9%

A company with aggressive equity compensation plans may show strong revenue growth but much slower EPS growth once dilution is factored in.

## Should You Exercise Your ESOS?

The decision to exercise depends on:

**1. Intrinsic value**: Is the current market price meaningfully above the exercise price? Out-of-the-money options (market < exercise) have no intrinsic value and should generally be held or let expire.

**2. Time to expiry**: Options with significant time remaining have time value even if currently out-of-the-money — early exercise destroys time value.

**3. Tax timing**: In many jurisdictions, the tax event is at exercise. Exercising and selling in the same tax year triggers ordinary income tax on the full spread. Exercising and holding may convert some of the gain to capital gains treatment (depending on jurisdiction and holding period).

**4. Concentration risk**: Holding unexercised options represents a large, concentrated bet on your employer's equity. Diversification considerations may argue for exercising and selling, even if the tax cost is suboptimal.

## Authoritative Sources

For deeper background and primary-source data on this topic, the following authoritative sources are useful starting points:

- [SEC — Securities and Exchange Commission](https://www.sec.gov/)
- [FINRA](https://www.finra.org/)

## Conclusion

ESOS — Employee Share Option Schemes — align employee incentives with shareholder returns by giving employees the right to participate in the company's equity upside. For employees, the key decisions are around vesting timelines, exercise timing, and tax optimisation. For investors, ESOS represents dilution that must be factored into valuation via diluted share counts. Understanding both the employee-side and investor-side of equity options makes you a more sophisticated participant in either role.

Warren at [heywarren.com](https://heywarren.com) helps employees evaluate equity compensation packages and investors assess dilution impact from employee option schemes.

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## Related Reading

**More from Warren**:
- [Restricted Stock Units (RSUs): What They Are and How They're Taxed](/blog/restricted-stock-units)
- Vesting Schedule: How Employee Equity Vesting Works
- [Diluted EPS: Why Diluted Earnings Per Share Matters to Investors](/blog/diluted-eps)

**Authoritative sources**:
- [HMRC — Employee Share Schemes](https://www.gov.uk/tax-employee-share-schemes)
- [IRS — Employee Stock Options](https://www.irs.gov/taxtopics/tc427)
- [SEC — Stock Options and Equity Compensation Disclosures](https://www.sec.gov/cgi-bin/browse-edgar)
