Working During Annual Leave: Can You Take a Second Job?

There is no UK law that stops you working for someone else while you are on annual leave from your main job. The Working Time Regulations 1998 set out when you can take leave and how it must be paid; they say nothing about what you do with the time.

Your contract is a different matter, and so is the 48-hour weekly limit. Between those two, most of the real answer lies — and the people who come unstuck are almost always the ones who assumed “it’s my time off” was the end of the analysis.

Key Takeaways

• No statutory prohibition on working elsewhere during annual leave. The restriction, if any, is contractual.
• The 48-hour weekly average applies across all your jobs combined, not per employer. ACAS is explicit that each employer should discuss opting out in that situation.
• Exclusivity clauses are unenforceable in zero-hours contracts under section 27A of the Employment Rights Act 1996.
• Working for a competitor, or using confidential information, is the fastest way to turn a lawful second job into gross misconduct.

What the Working Time Regulations Do and Do Not Say

Regulation 13 gives you four weeks’ leave, regulation 13A adds 1.6 weeks, regulation 15 governs the dates, and regulation 16 governs the pay. None of them condition the entitlement on rest actually happening.

The purpose of annual leave in the underlying case law is rest and recuperation, and that purpose is why regulation 13(9) bars payment in lieu except on termination — the law does not want workers selling their rest back. But that principle constrains what your employer may do, not what you choose to do with a Tuesday in August.

So the statutory answer is short: your employer cannot refuse leave because it suspects you will spend it working, and it cannot claw back holiday pay because you did.

What Your Contract Can Restrict

This is where the real limits sit. Four clause types are common in UK contracts, and they have very different force.

Clause	What it does	How enforceable
Exclusive service	Bars any other paid work during employment	Generally enforceable, except in zero-hours contracts
Notification / consent	Requires you to disclose other work and get approval	Widely enforceable; approval should not be unreasonably withheld if the clause says so
Non-compete during employment	Bars working for a competitor	Strongly enforceable while employed
Confidentiality	Bars using or disclosing employer information	Always enforceable, and survives termination

Breaching an exclusive service clause is a contractual breach, and depending on the circumstances it can be a disciplinary matter up to and including dismissal. Breaching confidentiality or working for a direct competitor is normally treated as gross misconduct.

The important exception is zero-hours work. Section 27A(3) of the Employment Rights Act 1996 makes any provision in a zero-hours contract prohibiting work under another arrangement unenforceable, and a worker on such a contract cannot lawfully be dismissed or subjected to a detriment for taking other work. If you are on a zero-hours contract, an exclusivity clause in it is simply void.

The 48-Hour Limit Is the Rule Most People Miss

Regulation 4(1) caps a worker’s average working time at 48 hours per seven days, normally averaged over 17 weeks. ACAS guidance confirms the limit applies across all of a worker’s jobs, and that where a worker will exceed 48 hours on average across those jobs, each employer should discuss an opt-out with them.

That has three consequences.

1. You may need to sign an opt-out with more than one employer. GOV.UK confirms the agreement must be voluntary and in writing, and cannot be forced on you.
2. You can cancel an opt-out at any time, giving between 7 days and 3 months’ notice depending on what the agreement says.
3. Some workers cannot opt out at all — including airline staff, seafarers, and road transport workers under drivers’ hours rules. In those sectors a second job that pushes you over the limit is a compliance problem for both employers, not a private matter.

Annual leave weeks do not create a loophole here, because the 17-week reference period averages across them.

Where a Second Job Becomes a Real Problem

Five scenarios turn a lawful arrangement into a disciplinary one.

• Working for a competitor. Even a single shift. This is the most common trigger for gross misconduct findings.
• Using your employer’s clients, data, or materials. Confidentiality and IP clauses do not switch off during leave.
• Working while on sick leave from the main job. This is a different question from annual leave, and it is far more dangerous. If you claim to be too ill to work but are working elsewhere, expect a fitness-to-work investigation — see our UK statutory sick pay guide.
• Returning unfit. Physically demanding second work that leaves you unable to perform your main role safely engages health and safety duties on both sides.
• Concealing it where your contract requires disclosure. The dishonesty usually causes more damage than the second job.

A worked scenario

Leah is a full-time marketing executive contracted to 37.5 hours. She takes two weeks’ annual leave and works 40 hours across those two weeks for a friend’s events company.

• Statutory position: nothing wrong. She was on leave and worked elsewhere.
• 48-hour check: across her 17-week reference period, adding 40 hours to her regular 37.5-hour weeks brings the average to roughly 39.9 hours per week. Comfortably under the limit — no opt-out needed.
• Contract check: her contract requires her to notify her employer of any other paid work. She did not. That, not the work itself, is the breach.

Change the second job to a marketing role at a rival agency and the analysis collapses entirely: competitor plus non-disclosure is a dismissal case regardless of the hours.

What This Means for You

If you are thinking about a second job, run four checks in order:

1. Read your contract’s exclusive service, notification and non-compete clauses. If you are on a zero-hours contract, any exclusivity clause is void.
2. Add your combined average hours and see whether you cross 48. If you do, ask both employers about opt-out agreements.
3. Confirm the second employer is not a competitor and that no confidential information will travel with you.
4. Disclose in writing if your contract asks you to. Ask for the approval in writing too.

If you are an employer, decide what you actually care about and write only that. Blanket exclusivity clauses are increasingly unrealistic, unenforceable for zero-hours workers, and a recruitment drag. A notification clause plus a tight non-compete-during-employment clause protects the business without policing people’s weekends.

Also check your working time compliance. If your staff are likely to hold second jobs, you have a duty under regulation 4(2) to take all reasonable steps to keep average hours within the limit, and ACAS recommends a health and safety risk assessment where someone will exceed it. That is impossible without accurate records of hours and absence in the first place — the same records that underpin your annual leave entitlement obligations.

Leave Balance gives you a single accurate record of who is off and when, so working time and leave compliance rest on data rather than recollection. Flat $10/month, unlimited employees, 14-day free trial.

This article is general information about UK employment law, not legal advice. Check your own contract, and take advice on your specific circumstances.