Non-compete clauses in the UK: what employers can and can’t enforce

Many restrictive covenants are copied from a template and never tested. The problem appears when a key salesperson or director leaves for a competitor and the business finds its clause is too wide to enforce. This guide looks at non-competes and the other common restrictions from the employer’s side: what you can protect, how to draft covenants that stand a realistic chance, and what enforcement involves. If you’re an employee checking your own contract, our guide on whether your restrictive covenants are enforceable is written for you.

The starting point: restraint of trade

Any term restricting what someone can do after their employment ends is a restraint of trade, and unenforceable unless the employer shows it protects a legitimate business interest and goes no further than reasonably necessary. That the employee signed it, or was well paid, doesn’t decide the point. Public interest also plays a part, though it rarely decides cases.

Courts apply this more strictly to employment contracts than to covenants given on the sale of a business, so wording that works in a share purchase agreement may fail in an employment contract.

What employers can legitimately protect

There are three recognised interests: trade secrets and genuinely confidential information that would harm the business in a competitor’s hands (pricing, margins, strategy, unreleased products); customer and supplier connections the employee builds through their role; and the stability of the workforce, which supports a restriction on poaching colleagues.

What you can’t protect is the employee’s general skill and knowledge, or your interest in not facing competition. A non-compete whose real purpose is to stop a good employee working for a rival will fail.

The main types of covenant

Non-compete clauses. These stop the employee working for, or setting up, a competing business for a period. They’re the hardest to justify because they prevent work entirely. Courts generally expect the employer to show why a non-solicit or non-dealing clause wouldn’t have been enough, which usually comes down to confidential information that a competitor could use and that can’t be policed any other way.

Non-solicitation of clients. These stop the employee approaching clients. They’re easier to justify because they protect specific relationships and leave the employee free to work.

Non-dealing clauses. These go further than non-solicitation by stopping the employee doing business with clients even if the client makes the approach. They’re useful where it would be hard to prove who contacted whom, but they need more justification than a non-solicit.

Non-poaching of staff. These stop the employee recruiting former colleagues. They’re more likely to be upheld if limited to staff the employee worked with, above a certain level of seniority.

How reasonableness is judged

Reasonableness is assessed as at the date the covenant was entered into. So a covenant signed by a junior recruit is judged by that junior role even if they later become a director, and covenants should be refreshed on promotion. Covenants introduced mid-employment need fresh consideration, such as a pay rise or promotion expressly linked to accepting them; continued employment alone is a risky basis. And one set of covenants for every employee is unlikely to be reasonable for most of them.

There’s no fixed rule on length. Non-competes of three to six months are common and more likely to be upheld, and 12 months is sometimes enforced for senior people with real strategic knowledge. Client non-solicitation and non-dealing clauses often run for six to 12 months. The right length depends on how long the information stays useful or how long it would take to bed a replacement into the client relationships. Geography should match where the business and the employee actually operate, and many covenants now define the restriction by clients or activities rather than a map, which is often easier to defend.

Is there a statutory limit on non-competes?

Not at present. In 2023 the previous government said it would cap non-competes at three months, but that was never legislated. The current government published a working paper in late 2025 setting out options for reform, and non-competes are not part of the Employment Rights Act 2025. For now the common law test above is the only control, but it’s an area to watch before you roll out new covenants across a workforce.

Drafting covenants that hold up

A court won’t rewrite an unreasonable covenant into a reasonable one. It can sometimes delete words that make a clause too wide and enforce what’s left, provided the remainder still makes sense and the deletion doesn’t change the nature of the obligation. That’s why good covenants are drafted as separate, free-standing restrictions rather than one long sentence.

In practice, tie client restrictions to clients the employee dealt with in a defined period before leaving (often 12 months), define “restricted business” by the activities the employee was actually involved in, and offset garden leave against the post-termination restrictions, since a court looks at the total time the employee is kept out. It also helps to record why the restrictions are needed for that role.

Garden leave is often the more reliable tool. An express garden leave clause lets you keep the employee on full pay but away from clients and information during their notice period. They’re still employed, so they can’t join a competitor. Courts are generally more comfortable with garden leave than with a long post-termination non-compete, though they can still refuse to enforce an unreasonably long period of it.

What enforcement involves

Enforcement usually means applying for an interim injunction to stop the breach until trial. Speed matters: delay can itself be a reason to refuse relief, and covenants often expire before a trial could happen. The application is expensive, and the employer normally has to undertake to compensate the employee if the injunction turns out to have been wrongly granted.

An employer that has itself committed a serious breach of the contract, for example by dismissing without the notice it owed, may lose the right to rely on the covenants. Well-advised employers make sure they have a clear contractual right to pay in lieu of notice and use it properly. Separately, an employee who has taken confidential information may face other claims, and a court can sometimes grant an injunction to stop them profiting from that head start, whether or not the covenants are enforceable.

If you’re on the other side of the table

For employees, the same points are the basis for negotiation. Limiting client restrictions to clients you dealt with, shortening the non-compete and offsetting garden leave all move the clause closer to what a court would enforce, which suits both sides.

If you want a second view on a set of covenants, whether you’re issuing them or being asked to sign them, QuickLegalCheck reviews the clauses and explains in plain English where they look wider than necessary. It isn’t legal advice, so if you’re facing a live dispute over an existing covenant, see our comparison page for when a solicitor is the better option.