Employers commonly ask employees to work overtime to carry out work outside normal hours, for example because of an increased volume of regular work, a temporary crisis in resourcing, or to cover for absences. One area of controversy is the treatment of overtime in holiday pay calculations (Lock v British Gas Trading Ltd).
Employees can be forced to work overtime, whether paid or unpaid, only if this is provided for in their contract of employment. However, it is common practice for employees to work unpaid overtime from time to time, to meet the reasonable requirements of the business.
Employers must bear in mind when asking employees to work overtime the maximum 48-hour working week under the Working Time Regulations 1998. An opt-out is available if the employee agrees.