The strict rule is that performance must be complete and exact
Cutter v Powell, Re Moore and Landauer
For a divisible (severance) contract where the contract has separate obligations non completion of one part by a party is not a breach of the whole contract
Ritchie v Atkinson, Taylor v Webb
‘Substantial’ is considered on a case to case basis
Hoeing v Isaacs, Bolton v Mahadeva
If a party accepts part performance of a contract, through a specific acknowledgement the other party is entitled to payment of what he has performed
Sumpter v Hedges, Roberts v Havelock
Where a party prevents the other from carrying out performance, the innocent party is entitled to payment for any wasted work
Planche v Colburn
There are specific rules on time of performance
Union Eagle v Golden Achievement, Macdonald v Startup
If a time or date is specified as being “of the essence” within the contract, it will be a condition of the contract
Topallson v Rolls Royce
Where no date or time is specified it must be completed within a reasonable time and so this will be an innonimate term
Astea v Time Ltd
Parties may also be able to give “reasonable notice” late requested completion date after the contract has been created
Charles Rickard v Oppenheim