An employment contract can be varied by agreement between the parties. Sometimes, employers have a right to make unilateral variations to some terms of the contract. In the absence of such a right, an employer cannot unilaterally vary the terms and conditions of employment.

It is important to get advice about possible variations of a contract of employment. Sometimes, an attempt to vary the terms of the contract can amount to a repudiation, allowing the innocent party to elect to terminate the contract and sue for damages.