Working hours are a fundamental contract term. Changing them without consent is a breach of contract — but the remedy depends on how serious the change is and what your contract says.
Hours Changes: What Requires Your Consent
| Change | Requires consent? |
|---|---|
| Changing start/end time by 1 hour | Usually — unless flexibility clause allows |
| Moving from set hours to shift rota | Almost always — fundamental change |
| Increasing contracted hours | Yes |
| Reducing contracted hours (pay cut) | Yes |
| Requiring occasional overtime beyond contract | No if contract includes overtime obligation |
Responding to an Unlawful Hours Change
Immediate action:
- Continue attending work on your existing contracted hours if safe to do so
- Send written objection within days: “I am working under my existing contracted hours. I do not accept the proposed variation and am seeking to resolve this through the grievance process.”
- Submit a formal grievance
Do not:
- Simply work the new hours without objecting for more than a week or two
- Refuse to work without first seeking advice
- Resign without taking advice (risks losing constructive dismissal rights if not done correctly)
If the Change Has Already Been Imposed
If you have been working new hours for some time without objecting, it becomes harder to argue you have not accepted the change. Courts may infer acceptance from conduct if you worked the new hours for months without raising it.
If this applies to you, a tribunal may still find the change was unlawful but assess your conduct as a contributory factor.
The Constructive Dismissal Route
If the hours change is severe — reducing pay significantly, making work practically impossible, or fundamentally altering the nature of your role — and you resign as a result, you may be able to claim constructive dismissal. Requirements:
- 2+ years’ continuous service
- Serious breach of contract by the employer
- You resign promptly after the breach (not weeks or months later)
- You made clear you were not accepting the change
Your Next Steps if Hours Are Changed Without Agreement
If your employer has imposed a change to your contracted hours without your agreement:
- Write a formal objection — state clearly that you have not consented to the change and that you are working under protest
- Raise a grievance — follow the employer’s grievance procedure to formally challenge the change
- Consider “working under protest” — you can continue working the new hours while explicitly stating you have not agreed to the change. This preserves your position for any future claim while avoiding immediate dismissal
- If the impact is severe — if the change fundamentally undermines your contract (e.g. hours cut from full-time to part-time without agreement, removing contractual shift premiums), you may have grounds to resign and claim constructive unfair dismissal
- Seek ACAS advice — ACAS Early Conciliation can be used if you wish to challenge the change formally without immediately resigning
Constructive dismissal claims require careful handling — legal advice before resigning is strongly recommended, as resignation itself ends your employment and you must then prove the breach was sufficiently serious.