Implied term

Courts will imply terms only where the contract does not work without them. They are terms that "go without saying". It is simply a matter of making a contract functional which otherwise would not be.

I believe the tests are "business efficacy" (the term must be necessary to give the contract business effect; if the contract makes business sense without it, the courts will not imply a term), articulated in the great case of The Moorcock (1889) 14 PD 64, or the "officious bystander test" and it was articulated in the almost equally great case of Shirlaw v. Southern Foundries [1939] 2 KB 206.