An employer does not have an automatic right to vary an employee's terms of employment. The extent to which employers can unilaterally change an employee's terms or working arrangements will depend entirely on the terms themselves.

If the contract contains flexible clauses or incorporates machinery for change (such as having a staff handbook 'as issued from time to time incorporated into the contract) then the employer will be able to alter the terms in line with these clauses.

If there is no flexibility or machinery for change then employers must follow the correct procedure if they want to alter an employee’s terms of employment in order to minimise the possibility of claims for damages and/or compensation relating to the change.