Employer requiring extra shifts

Short answer

Whether your employer can require you to work extra shifts or hours depends mainly on what your contract says, together with some overriding legal limits. The starting point is that you are obliged to work the hours set out in your contract, and no more. Your employer cannot simply impose additional hours or shifts unless the contract gives them the right to do so, or you agree.

What your contract says is the key

The first thing to check is the wording of your written contract, statement of terms, staff handbook or any zero-hours or bank arrangement.

If your contract sets fixed hours and contains no overtime clause, then in general you are only required to work those contracted hours. Additional shifts would be a change to your terms, which normally needs your agreement.

Many contracts contain an overtime or flexibility clause. A common example is wording such as “you may be required to work reasonable overtime from time to time in accordance with the needs of the business”. Where such a clause exists, you can be required to work some extra hours, but only where the requirement is genuinely reasonable, occasional rather than constant, and linked to a real business need. A clause of this kind does not entitle an employer to demand large amounts of extra work as a matter of routine.

If the contract says overtime is voluntary, or is silent on the point, you are generally entitled to decline extra hours.

Zero-hours, casual and “agreed availability” arrangements

If you are on a zero-hours or casual contract, the position is usually the reverse of a fixed-hours contract: the employer is not obliged to offer work, and in a genuine zero-hours arrangement you are not obliged to accept the shifts offered. Your employer cannot lawfully force you to take shifts beyond what you have agreed, and since 2015 exclusivity clauses in zero-hours contracts (preventing you working elsewhere) are unenforceable.

If you have given the employer set “agreed availability”, that agreement defines when you can be asked to work. Being asked to work outside that availability is a request you can normally decline, unless your contract specifically allows the employer to vary or extend it.

Overriding legal limits that apply regardless of the contract

Even where a contract permits extra hours, the Working Time Regulations 1998 impose limits that apply whatever the contract says.

You cannot be required to work more than an average of 48 hours a week, normally averaged over a 17-week reference period, unless you have signed an individual opt-out. An opt-out must be voluntary and in writing, and you can cancel it by giving notice (usually seven days, or up to three months if the contract specifies). Your employer cannot force you to opt out, and cannot dismiss or subject you to a detriment for refusing.

You are also entitled to minimum rest: normally at least 11 consecutive hours of rest in each 24-hour period, an uninterrupted 24 hours off in each seven days (or 48 hours in each fortnight), and a 20-minute break where you work more than six hours. Extra shifts that cut across these entitlements are unlawful.

If you are under 18, stricter rules apply: generally no more than 8 hours a day or 40 hours a week, and these limits cannot be opted out of.

Pay for extra hours

If you are paid hourly, you must be paid for all hours you actually work, and your average pay must not fall below the National Minimum or Living Wage. There is no automatic legal right to an enhanced overtime rate unless your contract provides one; extra hours can be paid at your normal rate unless agreed otherwise. Salaried staff may find their contract already covers reasonable additional hours within the salary.

Other considerations that can change the position

Health and safety and disability. If working extra hours would put your health at risk, or you have a disability, requiring additional hours may raise duties under health and safety law or the duty to make reasonable adjustments under the Equality Act 2010.

Caring and family responsibilities. A refusal that disproportionately affects, for example, women with childcare responsibilities could give rise to indirect discrimination arguments, and you may have the right to request flexible working.

Custom and practice. If regular overtime has been worked and paid for a long time, it can in some circumstances become an implied contractual term, cutting both ways.

Practical next steps

1. Read your contract, statement of terms and staff handbook carefully, focusing on any hours, overtime, flexibility, availability or variation clauses.

2. Check whether you have ever signed a 48-hour opt-out. If you have and no longer wish to work long hours, you can withdraw it in writing by giving the required notice.

3. If you believe the request goes beyond what your contract allows, raise it politely in writing, asking the employer to identify the contractual basis for requiring the extra hours. Keep a record of shifts, hours worked and any pressure applied.

4. Try to resolve it informally first, then through your employer’s grievance procedure if needed. ACAS offers free confidential advice and can help before matters escalate.

5. If you are being forced to work beyond the 48-hour average without a valid opt-out, or being denied rest breaks, that is a breach of the Working Time Regulations and can be raised with your employer and, if necessary, the Health and Safety Executive or a tribunal. If you are dismissed or treated badly for refusing unlawful hours or for cancelling an opt-out, you may have a claim for automatic unfair dismissal or unlawful detriment.

Key missing facts

The precise answer turns on details I do not have: the exact wording of your contract and any overtime or flexibility clause, whether you are salaried or hourly, whether you are on a fixed-hours or zero-hours arrangement, whether you have signed a 48-hour opt-out, and how frequent and substantial the extra hours being demanded are. If you can identify those points, the position becomes much clearer.