The legal document many business owners don't realise they need until it's too late

The UK economy shows signs of growth, however many SME owners remain in cautious mode. The priority for many is protecting what they’ve worked hard to build, ensuring they’re on solid footing for the future. 

It’s a trend reflected across the market. The value of M&A activity fell by 21.1% in Q1 2026 according to ONS data, while the British Business Bank also reports that smaller firms are increasingly turning to finance to strengthen resilience and maintain stability rather than pursue fund growth.

As business owners look for practical ways to strengthen their position and reduce risk, shareholder agreements are increasingly in popularity. Yet, despite their importance, they remain one of the most overlooked legal documents among SMEs.

Many owners assume a shareholder agreement is only needed when taking on investment or preparing for a sale. In reality, its value is often long before then. It provides clarity when the unexpected happens, whether that’s a disagreement between shareholders, an unplanned exit or a major business decision that proves difficult to resolve.

The risks of operating without one

Many businesses start with a shared vision. Founders, family members and long-standing colleagues often know and trust each other, making formal agreements feel unnecessary in the early days.

However, the challenge is that businesses evolve. Priorities change, personal circumstances shift and people can develop different views about the future of the company. This can lead to problems between shareholders. One shareholder may want to step back from day-to-day involvement. Others may disagree over dividends, investment plans or growth strategy. While some shareholders may decide they want to leave altogether. Without a shareholder agreement, these situations can quickly become stressful, time consuming, costly and complex. 

One of the most common issues involves the transfer of shares. If a shareholder wants to sell, the remaining owners may have little control over who acquires those shares. Equally, events such as death, illness, incapacity or divorce can lead to significant complications over ownership interests without clear provisions already in place.

Deadlock can also become a problem, where shareholders have equal voting rights.

When no one can agree a way forward and without a framework for resolving disputes, important decisions can stall and disputes can escalate into expensive, time-consuming legal battles.  Too often, businesses only discover these risks when they’re already dealing with them.

What should a shareholder agreement include?

Protecting the people behind the business

A robust shareholder agreement sets out the rights and responsibilities of each shareholder and establishes how those rights can be exercised. By documenting these clearly and from the outset, everyone knows where they stand as the business grows.

Keeping control of ownership

If a shareholder wants to leave, retire or sell their shares, the agreement should outline exactly what happens next. Without these provisions, existing owners can find themselves in partnership with individuals they did not choose to work with.

Protect against dilution

Imagine spending years building a successful company only to discover your ownership stake has been diluted because new shares have been issued.

A shareholder agreement can set out clear rules around how future share issues are handled and whether existing shareholders have the opportunity to maintain their percentage ownership.

Giving minority shareholders a voice

Not every shareholder owns a controlling stake in the business, but that doesn't mean their interests should be overlooked. An agreement can ensure key decisions require broader approval, helping protect everyone including minority shareholders.

Planning for life's unexpected events

Business owners rarely like discussing retirement, illness and death but failing to plan for these events can create significant uncertainty for both the company and the families involved. A shareholder agreement can set out exactly what happens if someone leaves the business unexpectedly, how their shares will be valued and who has the legal right to acquire them.

Providing a process when disagreements arise

Even the strongest relationships face disagreements from time to time and if there are no agreed routes for resolving the disputes, they can quickly become disruptive. Having a clear process in place can help resolve issues quickly, preventing them turning into lengthy and costly legal battles.

Protecting confidential information

For many businesses, confidential information is one of their most valuable assets. Well-drafted confidentiality clauses help safeguard sensitive business information both during a shareholder's involvement with the company and after they leave.

Practical steps business owners can take now

Firstly, it’s important to check whether a shareholder agreement exists at all. If one is already in place, then check whether it still reflects the current position of the business.

Ownership structures, shareholder roles and commercial objectives often evolve over time, and an outdated agreement may not provide the level of protection originally intended.

It is also a good idea to ensure any agreement works alongside the company's Articles of Association and any wider succession planning arrangements as consistency across these documents is essential.

The reality is that no business owner can predict what the future holds. What they can do is put the foundations in place to deal with whatever comes next. A well-drafted shareholder agreement won’t stop challenges arising, but it can make them far easier to navigate when they do.