Employee Share Option Scheme (ESOS) in the UK: A Startup Guide

If you’re building a startup or growing an SME, you’ve probably felt the squeeze: you want to hire and keep great people, but cash needs to stay in the business.

That’s where an employee share option scheme (often shortened to ESOS) can be a powerful tool. It lets you offer equity incentives (the chance to own shares in your company later) without handing over shares on day one.

But share options aren’t just a “nice-to-have perk”. They’re a legal and tax-heavy area, and the way you set up your scheme can have a big impact on control, compliance, and future fundraising.

In this guide, we’ll walk you through what an employee share option scheme is, how it works in the UK, the main choices you’ll need to make, and what to put in place so you’re protected from day one. This guide is general information only, and Sprintlaw doesn’t provide tax, financial or valuation advice. UK share scheme tax treatment (including HMRC reporting and any valuations) depends on your circumstances, so it’s important to take specialist tax advice before implementing a scheme.

What Is An Employee Share Option Scheme (And Why Do SMEs Use One)?

An employee share option scheme is a structured way for your business to grant selected team members an option to buy shares in the company at a later date (usually at a fixed price).

In simple terms:

• You’re not giving shares today – you’re giving a right to buy shares later.
• The right typically “vests” over time – e.g. 25% after one year, then monthly/quarterly thereafter.
• The option is usually conditional – for example, the person must still be employed, or a “sale event” must happen.

For startups and SMEs, the appeal is practical:

• Attract talent when you can’t match larger salaries.
• Keep key people by linking upside to staying and building value.
• Align incentives so employees think like owners (without giving them voting rights immediately).
• Support growth and fundraising by showing you have a thoughtful reward structure.

That said, share options are not “set-and-forget”. Without clear rules, you can create disputes around leavers, valuation, and what happens on a sale.

How Does An Employee Share Option Scheme Work In Practice?

Most UK employee share option scheme arrangements follow a similar lifecycle.

1) You Set The Scheme Rules

Before you grant options to anyone, you’ll typically create:

• A scheme plan (the overarching rules for the scheme).
• Option agreements (the individual contracts with each participant).
• Shareholder/constitutional alignment so the scheme fits your existing share structure and decision-making.

This is also where you decide key points like: who is eligible, how much equity will be available, and whether options vest over time or on specific milestones.

2) You Grant Options To Team Members

A grant gives the employee the option to acquire a certain number of shares, usually at an “exercise price”.

The exercise price may be:

• Market value at grant (often required for certain UK tax-advantaged arrangements), or
• A discounted price (can be possible, but may create additional tax complexity).

3) Options Vest Over Time (Or On Events)

Vesting is the mechanism that stops someone joining for 3 months, leaving, and walking away with equity.

Common vesting structures include:

• Time-based vesting (e.g. 4 years with a 1-year cliff).
• Performance-based vesting (linked to KPIs or milestones).
• Exit-based vesting (options vest on a sale of the company).

Be careful here: performance conditions can become unclear fast unless they’re drafted precisely.

4) The Employee Exercises The Option

Once vested, the employee can “exercise” the option (i.e. pay the exercise price and receive the shares).

In many startups, employees only exercise on an exit event (so they don’t have to find cash up front). The scheme needs to be drafted to support whatever approach you intend to take.

5) The Employee Becomes A Shareholder

When the option is exercised, the employee becomes a shareholder and will usually receive shares that are subject to the company’s existing rules (including any restrictions in your Shareholders Agreement).

This is why you need to plan your scheme around future governance and fundraising. Once someone holds shares, it’s much harder to “undo” mistakes.

What Are The Main Types Of UK Share Option Schemes (And Which Fits Your Business)?

There are different ways to structure an employee share option scheme in the UK. The right choice depends on your goals, your growth plans, and how much admin you’re willing to take on.

Tax-Advantaged Vs “Unapproved” Options

Broadly, share option schemes fall into two buckets:

• Tax-advantaged schemes (where legislation provides potential tax benefits if you meet strict conditions).
• Unapproved (non tax-advantaged) schemes (more flexible, but can be less tax efficient).

In the UK, commonly used tax-advantaged arrangements can include Enterprise Management Incentives (EMI) for eligible companies and employees, or Company Share Option Plans (CSOP) in some cases. Each regime has strict rules (including eligibility criteria, limits, and ongoing reporting requirements), and the tax outcome can depend on getting the terms and any valuation approach right.

Because the tax position depends heavily on your company and the individuals involved, it’s worth getting tailored legal advice alongside specialist tax advice early rather than trying to retrofit compliance later. Sprintlaw can help with the legal setup and documentation, but we don’t provide tax, valuation or financial advice.

Options Over Different Share Classes

Not all shares are equal. You can structure options over a particular class of shares (for example, non-voting or growth shares) depending on what your company’s constitution allows.

If you need different share rights (votes, dividends, liquidation preferences), you may need to adjust your company documents first, such as your Company Constitution.

This matters because investors often expect a clean and coherent cap table. If your option scheme creates unexpected rights or messy share classes, it can slow down fundraising or due diligence.

What Legal Issues Should You Think About Before Implementing An ESOS?

The biggest mistakes we see usually aren’t about “whether share options are a good idea”. They’re about governance, documentation, and what happens when things change (because they always do).

How Much Equity Are You Setting Aside?

Most businesses create an “option pool” (a percentage of the company reserved for future grants). From a legal perspective, you want to ensure:

• the company actually has the ability to issue the required shares later;
• the scheme rules don’t conflict with existing shareholder rights; and
• the approach won’t cause avoidable dilution surprises.

If you already have external investors (or plan to), the option pool size and mechanics can become a negotiation point.

Who Gets Options (And On What Conditions)?

You’ll want to define eligibility clearly. For example:

• employees only, or also contractors/advisors;
• full-time only, or also part-time;
• probation requirements; and
• performance milestones.

It’s also important to align this with your employment documentation, including a properly drafted Employment Contract. Options should usually be documented separately, but your employment terms should support confidentiality, IP ownership and (where appropriate) post-termination restrictions.

What Happens If Someone Leaves?

Leavers are where option schemes get tested.

Your scheme should spell out what happens if someone leaves due to:

• good leaver scenarios (e.g. redundancy, ill health);
• bad leaver scenarios (e.g. dismissal for gross misconduct);
• resignation; and
• termination during probation.

Common questions you’ll want answered in the documents include:

• Do unvested options lapse automatically?
• Does the employee have a short window to exercise vested options after leaving?
• Can the company buy back shares (if the person already exercised)?
• How is “good leaver” decided, and who decides?

Without clear rules, disputes can get expensive quickly, especially if the employee believes they were pushed out to avoid vesting.

Do You Need Shareholder Approval Or Board Approval?

This depends on your company structure and existing documents. Often, you’ll need board approval, and sometimes shareholder approval (especially if you’re creating new share classes or changing constitutional rights).

This is also where good corporate housekeeping matters: documenting decisions, keeping cap table records accurate, and ensuring Companies House filings are consistent.

Are You Handling Personal Data Properly?

An employee share option scheme involves processing personal data (identity details, grant details, potentially salary and performance information). If you’re storing and managing that information, make sure your internal approach is aligned with UK GDPR and the Data Protection Act 2018.

Many SMEs also need an external-facing Privacy Policy if they collect personal data through their website or platform (which is common once you’re hiring and growing).

What Documents Do You Need For An Employee Share Option Scheme?

If you’re aiming to implement an employee share option scheme properly, you’ll want documentation that is clear, consistent, and aligned with how your company actually operates.

While every business is different, the core documents often include:

• Scheme rules / plan (sets the framework, eligibility, leaver rules, exercise mechanics).
• Option grant letters or option agreements (sets out the individual’s grant, vesting schedule and conditions).
• Board and (if required) shareholder resolutions approving the scheme and specific grants.
• Updated cap table records reflecting the option pool and grants.
• Company constitutional alignment so issuing shares on exercise is legally straightforward (often within your Company Constitution).

Depending on your structure, you may also need:

• Updates to your shareholder arrangements so new employee shareholders are bound by the same rules as existing shareholders (often handled through a Shareholders Agreement).
• IP and confidentiality protections to ensure the value employees help create belongs to the business (often in an Employment Contract and/or IP assignment arrangements).

A quick word of caution: it’s tempting to grab a template online and “fill in the blanks”. The problem is that option schemes have lots of moving parts, and a template rarely matches your share structure, your investor expectations, or your intended leaver outcomes.

Getting the documents drafted properly upfront can save you major headaches later (especially during investment due diligence or a sale).

How Do You Implement An Employee Share Option Scheme Without Slowing Down Growth?

Done right, an employee share option scheme supports growth. Done poorly, it becomes a distraction.

Here’s a practical, startup-friendly approach that keeps momentum while still protecting the business.

Step 1: Get Clear On The Business Outcome You Want

Before you touch documents, decide what you’re trying to achieve. For example:

• Is the main goal retention for key hires?
• Are you using options to replace cash bonuses?
• Do you want options to only be exercised on an exit?

These decisions flow into vesting, exercise windows, and leaver terms.

Step 2: Check Your Current Structure And Paperwork

Many businesses only realise too late that their existing company paperwork doesn’t support what they want to do.

It’s worth checking:

• your share classes and whether you need new classes;
• pre-emption rights (rights existing shareholders may have to buy new shares first);
• drag/tag rights (particularly relevant if you’re thinking about an exit); and
• whether your employment documentation is up to scratch.

Step 3: Set A Sensible Option Pool And Internal Policy

Even if your documents are legally solid, you’ll save time if you also have a simple internal policy that covers:

• who can approve option grants;
• how grants are recorded;
• how vesting is tracked; and
• how leavers are handled in practice.

This reduces the risk of inconsistent promises being made verbally (which is where misunderstandings often start).

Step 4: Make Sure Your Contracts And Comms Don’t Create Confusion

Options can be motivating, but they can also be misunderstood. Be careful that your written and verbal communications don’t accidentally imply:

• guaranteed value;
• a guaranteed exit;
• employment rights that aren’t intended; or
• share ownership before exercise.

This is one reason it’s important to treat options as a separate legal arrangement, alongside (not inside) your Employment Contract.

Step 5: Stay On Top Of Ongoing Compliance

Once your employee share option scheme is live, keep good records.

That includes:

• signed option agreements;
• board approvals for grants;
• cap table updates; and
• clear leaver outcomes documented at the time someone exits.

If you’re raising investment, selling the business, or doing a restructure, clean and consistent records can save weeks of back-and-forth.

Key Takeaways

• An employee share option scheme can help startups and SMEs attract, retain, and motivate key team members without paying everything in cash.
• Options are not shares today – they’re a legal right to acquire shares later, usually subject to vesting and other conditions.
• The most important design decisions include who is eligible, how vesting works, leaver rules, and whether options can be exercised only on an exit.
• Your scheme needs to align with your broader company documents, including your Company Constitution and, where relevant, your Shareholders Agreement.
• Clear documentation matters: scheme rules, option agreements, approvals, and accurate records can prevent disputes and make fundraising due diligence much smoother.
• Share options can have significant tax implications and HMRC reporting requirements. Sprintlaw doesn’t provide tax, valuation or financial advice, so you should take specialist tax advice before implementing or relying on any share scheme.

If you’d like help setting up an employee share option scheme (or reviewing your existing structure and documents), you can reach us at 08081347754 or team@sprintlaw.co.uk for a free, no-obligations chat.