UK Employer Rules · 2026
Can my employer stop me having a second job or working elsewhere?
Legal basis
Exclusivity Terms in Zero Hours Contracts (Redress) Regulations 2015; Working Time Regulations 1998 (48-hour limit unless opted out); Implied duty of good faith / fidelity; common law restraint of trade principles.
When they CAN do it
Your employer CAN restrict second jobs if: (1) there's an express clause in your contract; (2) the second job creates a genuine conflict of interest (working for a competitor, breaching confidentiality); (3) the combined hours exceed the 48-hour weekly working time limit (and you haven't opted out); (4) the second work would impair your ability to perform your main role; (5) it would breach fiduciary duties (especially senior roles).
When they CANNOT do it
Your employer CANNOT: enforce an exclusivity clause if you're on a zero-hours contract; enforce exclusivity if you earn below £123/week (as of April 2026); ban all outside work without business justification; prevent you from working for non-competitors in unrelated industries; control your activity outside working hours where there's no impact on your role.
What you should do
1) Read your contract — look for exclusivity clauses, conflict of interest provisions, working time. 2) Check if you've signed a 48-hour opt-out. 3) Disclose the second job in writing to your employer if your contract requires. 4) Be specific: hours, employer, role — if no conflict, employer usually consents. 5) If they refuse without good reason, raise the issue in writing. 6) For zero-hours / low-earners: ignore exclusivity clauses (they're void by law) but disclose to avoid disciplinary risk. 7) Never breach confidentiality — even after you leave.
Worked example
Olivia (4 days/week marketing role) wanted to take on freelance copywriting evenings for a non-competing client. Her contract had a vague 'no outside work' clause. She asked her manager in writing, confirmed no client conflict, no working hours overlap, no use of company resources. Manager initially said no; HR confirmed the clause couldn't be enforced as written and approved with a written conflict-of-interest declaration. She earned £8,400 extra in year one.
Red flags — when to escalate
🚨 'No outside work whatsoever' clauses (over-broad, often unenforceable). 🚨 Refusal even after you confirm no conflict. 🚨 Clauses extending past your employment ending (these are 'restrictive covenants' and have separate strict rules). 🚨 Exclusivity clauses on zero-hours or under-£123/week contracts (void). 🚨 Demands to disclose income from second job.
Recruiter pro tip
Most employers care about three things only: (1) you're not working for a competitor; (2) you're not using their data or contacts; (3) your performance isn't suffering. If you can address all three in a written disclosure, almost no employer will refuse. The real risk isn't the second job itself — it's failing to disclose and being treated as a breach of trust. Always disclose, always in writing.
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