Call and Put Options in UK Shareholder Agreements

Call and put options often look like a small technical clause in a shareholders agreement, but they can decide who controls your company, when someone must sell, and how the price is worked out. Founders commonly make three mistakes here: they agree to option wording without understanding the trigger events, they focus on valuation but ignore timing and process, and they assume these clauses only matter if the business is already in dispute.

In practice, call vs put options can shape exits, investor protection, founder departures and deadlock scenarios long before anyone plans to sell. If you are negotiating investment terms, bringing in a co-founder, or trying to protect the business if a shareholder leaves, these clauses deserve careful attention before you sign a contract and before you spend money on company setup around a deal that may not work the way you expect.

This guide explains what call and put options mean in a UK business context, when they usually appear in shareholders agreements, the main drafting points to check, and the mistakes that can become expensive later.

Overview

A call option gives one party the right to require another party to sell shares. A put option gives one party the right to require another party to buy shares. In a UK shareholders agreement, both are usually used to manage risk around founder exits, bad leavers, investor exits, deadlock or agreed future sale events.

• Who holds the option and against whom it can be exercised
• What event triggers the option, such as resignation, misconduct, default, deadlock or failure to meet milestones
• Whether the option is mandatory, discretionary or subject to board or shareholder approval
• How the share price is calculated, including any discount or premium
• When notice must be given and how completion happens
• What happens if the company cannot legally buy back shares
• How the option works alongside pre-emption rights, drag along and tag along clauses
• Whether the wording is fair and commercially realistic for founders, investors and minority shareholders

What Call Vs Put Options Means For UK Businesses

Call vs put options is really about control over a future share transfer. The key question is simple: who gets to force the next step if a defined event happens?

A call option usually benefits the buyer. It gives that party the right, but not always the obligation, to buy shares from another shareholder if certain conditions are met. In a private company, that can help the remaining founders or investors remove a shareholder who has left the business, breached key obligations or become part of a deadlock.

A put option usually benefits the seller. It gives that party the right to require someone else to buy their shares. This can protect an investor who wants an exit route after a set period, or a founder who agrees to stay for a certain time but wants a clear mechanism to leave later.

How a call option works

A call option clause gives an identified person or group the right to purchase shares on pre-agreed terms. The clause should say:

• whose shares can be bought
• who can exercise the option
• what event activates it
• the valuation method
• the completion process

For example, if a founder leaves full-time employment with the company within two years, the remaining founders may have a call option to buy that founder's shares. The price might depend on whether the founder is classed as a good leaver or bad leaver under the agreement.

How a put option works

A put option clause gives the shareholder holding the option a contractual way to require a purchase. That can be useful where a party is investing on the basis that they will have a route out if the company is not sold or floated by a particular date.

For example, an investor may negotiate a put option allowing them to require the founders, another investor, or in some structures the company itself, to buy their shares after five years if no exit has happened. This raises practical and legal issues around affordability, enforceability and company law limits, so the drafting needs more than a headline right to sell.

Why these clauses matter in shareholders agreements

These options are not just exit mechanics. They influence bargaining power from day one.

If one side can force a sale and the other side has no matching protection, that imbalance may affect board control, dilution discussions, founder vesting and future fundraising. Investors often view option clauses as part of the overall risk package, alongside reserved matters, information rights and share transfer restrictions.

For SMEs, the problem is often that everyone agrees in principle on a fair outcome, but no one writes down the detail. That is where founders often get caught. A clause saying shares can be bought at fair market value does not answer who decides the value, whether minority discounts apply, or what happens if there is no willing buyer.

UK legal context to keep in mind

In the UK, private companies commonly regulate share transfers through their articles of association and a shareholders agreement. The two documents need to work together. If the agreement says one thing and the articles say another, the company may struggle to implement the transfer smoothly.

There are also company law points to check. A company buying back its own shares must comply with the Companies Act 2006 and any procedural requirements in its constitutional documents. That means an option that assumes the company can always buy the shares may not work in practice.

You also need to think about whether the clause could operate unfairly against a minority shareholder, especially where pricing is heavily discounted or the trigger is vague. A hard bargain is not automatically unlawful, but unclear drafting can create expensive arguments later.

When This Issue Comes Up

Call and put options usually come up when ownership is changing, risk is increasing, or the parties want a fallback plan before a problem appears. The best time to deal with them is before you sign, not after a relationship has broken down.

Founder departures

This is one of the most common situations. If a founder leaves early, the business may want the right to buy back some or all of their shares so that an inactive shareholder does not keep a large stake.

That often connects with good leaver and bad leaver provisions. A good leaver might receive market value or a formula price. A bad leaver might receive a lower price, sometimes limited to nominal value for unvested shares or in more serious cases all affected shares, depending on the agreed structure.

Investment rounds

Investors may ask for a put option as part of their downside protection, particularly in early-stage or closely held businesses where there is no obvious public market exit. Founders may also seek call rights to maintain stability if an investor defaults on funding commitments or becomes subject to insolvency events.

Before you agree, think about the commercial reality. A put option is only as useful as the buyer's ability and obligation to pay. If the likely buyer is the company, you need to sense check whether a future buy-back is legally and financially realistic.

Deadlock between shareholders

Where two founders or two shareholder groups have equal voting power, deadlock provisions may include a call or put structure. One side may be allowed to offer to buy the other's shares, or require a sale if a deadlock event remains unresolved after a set process.

This area needs especially careful drafting. Poorly designed deadlock options can encourage tactical behaviour. One party may create pressure on the business simply to trigger a favourable exit mechanism.

Joint ventures and strategic partnerships

If a company is set up by two businesses rather than individual founders, options may be used if one party changes control, stops contributing agreed resources, or breaches exclusivity obligations. In those cases, the option is often part of a wider governance package dealing with IP ownership, supply arrangements and management rights.

Employee or management equity arrangements

Senior team members who hold shares may be subject to call options if they leave employment. This helps align ownership with ongoing contribution, especially in startups where equity is part of the incentive package.

The documents must be clear about how those rights interact with employment contracts, service agreements and any separate equity plan. If the paperwork is split across several documents, inconsistent terms can cause real problems when someone leaves.

Pre-agreed exit planning

Some businesses build options into the agreement simply because they want certainty. A founder may want the right to sell after a minimum commitment period. An investor may want a route out if a trade sale has not happened by a certain date. A family-run SME bringing in external capital may want a way to regain full ownership later.

These are sensible commercial goals. The mistake is treating the option clause as boilerplate when it is really one of the most commercial clauses in the deal.

Practical Steps And Common Mistakes

The safest approach is to treat call vs put options as a practical process, not just a legal label. The clause needs to work on paper, under company law rules, and in a real-life dispute or exit.

1. Decide what problem the option is solving

Different triggers suit different business risks. A founder departure clause should not be copied into an investor exit clause without changes.

Before you sign, identify the exact situation you are planning for:

• a founder leaving the business
• an investor needing an exit route
• deadlock between equal shareholders
• default on funding commitments
• misconduct or breach of restrictive covenants
• change of control in a corporate shareholder

If the trigger is broad, define it carefully. Words like misconduct, material breach or deadlock need enough detail to reduce arguments.

2. Check who must buy or sell

This sounds obvious, but it is regularly mishandled. The clause should state whether the shares are bought by:

• another shareholder
• a group of shareholders in set proportions
• the company through a lawful buy-back process
• a nominated third party if the main buyer does not complete

Each route has different practical consequences. If the company is the intended buyer, make sure the deal documents reflect what the company can actually do under the Companies Act 2006 and its articles.

3. Get the valuation mechanism right

Most disputes about options are really disputes about price. A clause that says fair value may sound balanced, but it often leaves too much unresolved.

A better clause usually addresses:

• whether the price is fixed, formula-based or market value
• who determines market value, such as an independent accountant or valuer
• what assumptions apply to the valuation
• whether minority discounts apply
• whether any discount or premium applies for good leaver or bad leaver scenarios
• what information the valuer can review
• whether the valuation is final and binding except for manifest error

Founders often accept aggressive bad leaver pricing early on without realising how easy it may be for the trigger to arise later. If the price could drop to nominal value, the trigger wording must be very precise.

4. Line up the shareholders agreement and articles

The transfer rules in the articles of association should support the option clause. If pre-emption rights, board approval requirements or transfer procedures conflict with the shareholders agreement, completion may become messy.

This is especially relevant where the company has updated investment documents but old articles. Before you spend money on company setup for a funding round, check that the constitutional documents match the commercial deal.

5. Set out a workable process and timetable

An option is far more useful when the clause includes a clear mechanics section. That usually covers:

• how notice must be served
• the deadline for exercise
• how the number of shares is identified
• when the valuation happens
• the completion date
• what documents must be signed at completion
• what happens if a party refuses to cooperate

Without a timetable, one side may delay until the value changes or the commercial pressure becomes unbearable.

6. Think about funding and affordability

A put option can be commercially dangerous if the buyer may not have the cash to complete. A call option can also cause problems if several remaining shareholders are meant to buy in fixed proportions but one of them cannot afford to do so.

To reduce that risk, parties sometimes agree fallback mechanisms, staged completion, or a right for another shareholder to take up any shortfall. The right solution depends on the company structure and the reason for the option.

7. Do not ignore related clauses

Call and put options rarely stand alone. They need to be read with the rest of the deal documents, including:

• pre-emption rights on share transfers
• drag along and tag along provisions
• good leaver and bad leaver definitions
• founder vesting or reverse vesting arrangements
• reserved matters and board control rights
• employment contracts or service agreements for working shareholders
• confidentiality and restrictive covenant clauses

A common mistake is to negotiate a clean-looking option clause that clashes with these provisions. That can produce exactly the dispute the parties thought they had avoided.

8. Avoid vague fairness wording

Founders often prefer simple wording such as the parties will act reasonably and agree a fair price. That can help set tone, but it is not a substitute for detail.

If there is a conflict later, a court will focus on the contractual wording, not on what the parties vaguely expected. Precision usually protects relationships better than open-ended fairness language.

Common mistakes to avoid

• copying US or generic template language into a UK private company structure
• assuming a company buy-back is always available
• failing to define good leaver and bad leaver triggers clearly
• leaving valuation to future negotiation
• forgetting to update the articles of association
• giving one party a strong option right without checking the commercial balance elsewhere
• ignoring tax and accounting consequences until the deal is about to complete
• treating the clause as low-risk because everyone currently gets on well

The main risk is not just legal uncertainty. It is that the clause changes negotiating power at the worst possible moment, when someone wants out, cash is tight or the business is already under strain.

FAQs

What is the difference between a call option and a put option in a shareholders agreement?

A call option lets the holder require another shareholder to sell shares. A put option lets the holder require another party to buy shares. The difference is who controls the transfer right when the trigger event happens.

Are call and put options enforceable in the UK?

They can be, if they are properly drafted and consistent with company law, the articles of association and the rest of the transaction documents. Enforceability often turns on clear triggers, clear pricing and a workable completion process.

Can a UK company buy back shares under a put or call option?

Sometimes, but not automatically. A company share buy-back must follow the Companies Act 2006 and the company's constitutional requirements. If the option assumes the company can always purchase the shares, the clause may fail in practice.

What is a good leaver or bad leaver clause?

It is a clause that affects what happens to a departing shareholder's shares, often including whether a call option applies and at what price. The definition matters because it can significantly change the amount paid for the shares.

Do startups need call or put options in every shareholders agreement?

No. Some startups use simpler transfer restrictions and vesting arrangements instead. Options are most useful where the parties want a defined mechanism for founder exits, investor protection, deadlock or planned future sale rights.

Key Takeaways

• A call option gives a party the right to require a share sale, while a put option gives a party the right to require a purchase.
• These clauses matter most in shareholders agreements where founders, investors or management may leave, default, deadlock or need an exit route.
• The most important drafting points are the trigger event, who buys or sells, the valuation method, the timetable and how the clause fits with the articles of association.
• UK companies need to check company law requirements carefully, especially if the company itself may buy back shares.
• Vague wording around fair value or reasonable behaviour often creates disputes instead of preventing them.
• Before you sign a deal, sense check the clause against real founder scenarios, affordability and the rest of the governance documents.

If your business is dealing with call vs put options and wants help with shareholders agreements, share transfer clauses, founder exit terms, and company buy-back drafting, you can reach us on 08081347754 or team@sprintlaw.co.uk for a free, no-obligations chat.