Refusing shifts on zero-hours contract

Short answer

Yes, the essence of a genuine zero-hours contract is that you are free to decline offered work. The employer is not obliged to offer you a minimum number of hours, and in return you are not obliged to accept whatever is offered. Refusing a shift is not, in itself, a breach of contract if the contract truly imposes no obligation on you to work.

The harder question is whether the employer can respond by simply not offering you further shifts. Under a genuine zero-hours arrangement the employer generally has no legal duty to offer you any work at all, so a reduction in offered hours is often lawful. However, there are important limits. If the reason for cutting your hours is that you asserted a legal right, raised a protected concern, or relates to a protected characteristic, withholding work can be unlawful even on a zero-hours contract. New protections under the Employment Rights Act 2025 are also being introduced specifically to address this practice.

Why refusing a shift is normally allowed

A true zero-hours contract by definition contains no mutual obligation to offer or accept work. That mutuality point is central. Because you have no contractual duty to accept shifts, declining one is not misconduct and cannot properly be treated as a disciplinary matter.

There is one common exception to be aware of. Some contracts are labelled zero-hours but in fact require you to be available, or to accept work when offered, or contain a clause preventing you working elsewhere. If your contract obliges you to accept offered shifts, refusing could technically be a breach. You should check the actual wording of your contract, because the label matters less than the terms.

Exclusivity clauses are banned

If your contract tries to stop you from working for anyone else (an exclusivity clause) while offering you no guaranteed hours, that clause is legally unenforceable. Since 2015 exclusivity terms in zero-hours contracts have had no effect, and dismissing an employee or subjecting a worker to a detriment for breaching such a clause is unlawful. This matters because it means you cannot lawfully be penalised for taking other work when your own employer offers you nothing.

Can the employer withhold future work as punishment?

This depends heavily on the reason.

If the employer simply prefers to offer shifts to people who are more consistently available, and there is no unlawful reason behind it, then cutting your hours is generally lawful. On a genuine zero-hours contract there is usually no right to be given a particular level of work, so a commercial or availability-based decision to offer you fewer shifts is difficult to challenge.

It becomes unlawful where the withholding of work is a response to something legally protected. Key examples where reducing or removing your shifts could give rise to a claim include:

Detriment for asserting a statutory right, such as the right to paid holiday, the National Minimum Wage, rest breaks under the Working Time Regulations, or statutory sick pay. Punishing you by cutting hours because you insisted on these can amount to an unlawful detriment.

Whistleblowing, if you made a protected disclosure about wrongdoing and lost shifts as a result.

Discrimination under the Equality Act 2010, if the loss of work is connected to a protected characteristic such as sex, pregnancy, race, disability, religion or belief, age, or sexual orientation. Zero-hours workers are still protected against discrimination, so being denied shifts because, for example, you were pregnant or requested a disability-related adjustment is unlawful.

Trade union activity or asserting family-related rights, which also attract detriment protection.

So the label “punishment” is doing a lot of work here. The law does not prohibit an employer choosing not to offer you work; it prohibits doing so for a reason the law protects.

Ordinary explanations to consider

Before treating a drop in hours as unlawful retaliation, it is worth considering innocent explanations, because these are common and will often be the true reason. Reduced trade, seasonal downturn, another worker having greater availability, restructuring, or a genuine preference for staff who can cover the shifts actually needed can all lawfully explain fewer offers. Establishing that the real reason was retaliation, rather than an ordinary operational choice, is usually the central evidential difficulty in any claim.

Employee or worker status matters

Your status affects your remedies. Most zero-hours staff are workers rather than employees, which is enough for protection against discrimination, whistleblowing detriment, unlawful deductions and the exclusivity protections. Unfair dismissal generally requires employee status. If a course of conduct means work simply dries up, that is often treated as detriment rather than dismissal, unless you can show the relationship was in truth one of employment that was terminated. If you have accrued a series of regular shifts over a long period, there may be an argument that mutuality of obligation has arisen and that you are actually an employee, which would broaden your rights, but this is fact-specific.

Upcoming changes under the Employment Rights Act 2025

The Employment Rights Act 2025 introduces significant new protections aimed directly at this problem, although the detailed rules will be brought in through regulations and are being phased in rather than being in force immediately. The key measures relevant to you are a right to reasonable notice of shifts, a right to payment for shifts cancelled, moved or curtailed at short notice, and a duty on employers to offer guaranteed hours to qualifying workers who have worked regular hours over a reference period. Crucially, workers will be able to accept or reject a guaranteed-hours offer without penalty, and there will be protection against detriment for exercising these new rights. When these provisions are commenced they will make it harder for an employer to use the withdrawal of shifts as an informal disciplinary tool. Because commencement is staged, you should check the current in-force position for the specific right you want to rely on.

Evidence to gather

If you think shifts are being withheld for an unlawful reason, start building a record now:

1. Keep your contract and any written terms, especially anything about accepting shifts, availability or exclusivity.

2. Keep a log of the shifts you were offered and worked before and after the incident, to show the pattern and timing of the drop.

3. Save messages, rotas, emails or texts, particularly anything where a manager links the reduction to your refusal, a complaint, sickness, pregnancy or similar.

4. Note dates, times, and who said what, including any comments suggesting the real reason.

Practical next steps

1. Raise it informally first. Ask the manager, ideally in writing, why your hours have dropped and request to be offered shifts on the same basis as before. A calm written query often either resolves it or produces a revealing answer.

2. If that fails, use the employer’s grievance procedure in writing, setting out the facts, the timing, and the protected reason you believe is behind the decision.

3. Consider Acas early conciliation. Acas can help resolve the dispute and, for any tribunal claim, contacting Acas to start early conciliation is a mandatory step before you can lodge a claim.

4. If it cannot be resolved and there is a genuinely unlawful reason, a claim to the Employment Tribunal may be possible, for example unlawful detriment, discrimination, or unlawful deduction from wages. Be aware of the strict time limit, which is normally three months less one day from the act complained of, subject to the extension for the Acas conciliation period. Do not let time run out while trying to resolve matters informally.

What would change the answer

The outcome turns on facts I do not have. It would help to know the exact wording of your contract, particularly whether it obliges you to accept work; whether you are treated as a worker or employee; how long and how regularly you have worked; the employer’s stated reason for offering fewer shifts; and whether the reduction followed something protected such as a complaint, sickness, pregnancy, or asserting a pay or holiday right. If the drop in hours is simply because business is quiet or others are more available, your options are limited. If it clearly followed you asserting a legal right or is linked to a protected characteristic, you may have a strong claim.