The terms of a contract of employment are made up from a number of different sources. The most obvious will be the express terms which have been agreed between the parties. Express terms may have been agreed either orally or in writing. It is also possible for certain terms contained in a collective agreement to be incorporated into an employment contract.
In addition to expressly agreed terms, a number of terms will be implied into an employment contract. Terms may be implied into an employment contract in a number of ways: to reflect the presumed intention of the parties, by custom and practice, by common law or by statute