How to Spot an Unfair Non-Compete Clause

Non-compete clauses are one of the most contested areas of UK employment law. They're extremely common, often unreasonably broad, and frequently unenforceable — but most employees sign them without question and then live in fear of them when they want to leave.

Here's the truth: a non-compete clause is only legally enforceable if it is reasonable. And many of the ones you'll encounter in standard employment contracts are not reasonable.

What makes a non-compete clause enforceable in the UK?

Under UK common law, a non-compete clause (technically a "restraint of trade" clause) is prima facie void — it's presumed invalid unless the employer can demonstrate it's justified. To be enforceable, it must:

• Protect a legitimate business interest — trade secrets, confidential information, or customer relationships the employee has developed
• Be reasonable in scope — covering only the activities genuinely necessary to protect that interest
• Be reasonable in duration — typically 3-12 months; anything longer is suspect
• Be reasonable in geographic area — limited to where the business actually competes

A clause that fails any of these tests may be wholly unenforceable. Courts will not "blue pencil" an unreasonable clause to make it reasonable — they'll strike it out entirely.

Red flag examples

This is almost certainly unenforceable. 24 months is very long. "Any business activity" is extremely broad. "Anywhere in the world" is geographically unreasonable for most businesses. "At any time during employment" means the scope could expand throughout your tenure without your knowledge.

What's more likely to be enforceable

This is more defensible: 6 months, direct competitors only, UK only, same role. A court is more likely to uphold this.

What to do if your contract has a broad non-compete

• Negotiate before you sign. Ask for the duration to be reduced and the geographic scope limited to where the business actually operates.
• Document your role carefully. A clause designed to protect customer relationships is less enforceable if you never had customer contact.
• Get legal advice before you act on it. If you want to join a competitor and you have a non-compete, don't just ignore it — get a solicitor's view on whether it's enforceable in your specific circumstances.