What is the maximum number of working hours an adult worker can work?

Every adult worker has the legal right to refuse to work more than an average of 48 hours a week, calculated over a reference period of 17 consecutive weeks, subject to certain exemptions, under the Working Time Regulations 1998. The 17-week period may be increased to 26 weeks for workers whose work keeps them away from home for long periods and for some other groups of workers. The 17-week period may be extended to up to 52 weeks under the terms of a collective agreement or workforce agreement that applies to particular workers or groups of workers.

Adult workers can opt out of the maximum 48-hour week by entering a written agreement with their employer.