Can an employer change an employee's hours where there is no contractual clause authorising it to do so?

An employer can change an employee's working hours where there is no contractual clause authorising it to do so, but this would involve following a process for a formal variation of contract. The starting point would be for the employer to try to reach agreement with the employee. The change can be made without difficulty if the employee agrees and it would be wise for the employer to ensure that the employee signs a document to acknowledge their agreement.

Where agreement is not forthcoming, the employer should commence a consultation process with the employee. The employer will need to show that there is a genuine business need for the change and that there has been genuine consultation with the employee with regard to the change. Once consultation has taken place the employer may bring in the change by terminating the original contract and re-engaging the employee immediately on new terms with the new working hours. It is recommended that the employer give the employee the amount of notice due under the original contract and then re-engage at the end of that notice period on the new terms.

The termination of the original contract will be a dismissal and there is a risk that the employee may challenge the termination as unfair. The employer will rely on "some other substantial reason" under s.98(1)(b) of the Employment Rights Act 1996 as being the potentially fair reason for dismissal. The reason for making the change and the consultation process will be factors in determining the fairness of the dismissal. The employee also has a duty to mitigate loss and it could be argued that if they do not accept the new contract with the revised hours there may have been a failure to mitigate loss. Employers should take particular care when a change in hours would affect employees with childcare responsibilities, as there is potential for claims of indirect sex discrimination where the proposed changes would adversely affect female employees.