What mechanisms are there to allow the employer to change the terms of a contract?

A contract may contain an express power or some machinery or procedure by which the employer can change certain terms within the employee's contract. For example, the contract may allow the employer to change a term after a period of consultation or after giving a specified period of notice. Such flexibility clauses will be very strictly interpreted and do not give the employer carte blanche to make any change it wishes. If the contract provides that the terms shall be those agreed from time to time with the union, a collective agreement will automatically change the contract terms. If terms contained in an employee handbook are incorporated into an employee's contract, a change to the handbook will be a contractual change.