Parties commonly use language such as "best endeavours" or "reasonable endeavours" to assume a less than absolute obligation under a contract. It is difficult to provide definitive advice on how any such wording is likely to be interpreted - whilst some broad principles have developed under case law, the precise effect of the wording will depend on the circumstances of the particular contract.

In the recent case of Jet2.com Limited v Blackpool Airport Limited, the High Court stressed that endeavours wording will mean different things in different situations. In that case, an airport and an airline agreed to use best endeavours to procure that the airline could promote its low-cost offering from the airport. The airport then allowed the airline to operate flights outside the airport's published opening times. When the airport subsequently reverted to its strict opening times, the airline claimed that this constituted a breach by the airport of its obligation to use best endeavours to promote the low-cost offering.

The High Court held, amongst other things, that a commitment to use best endeavours can be deemed to include an agreement to take steps which might operate to the commercial detriment of a party - the court did not believe that the parties would have intended a best endeavours obligation to allow either of them to abandon performance once it became commercially unprofitable for them to continue.

This underlines the importance of considering carefully the likely implications of any general endeavours wording. Given that it is impossible to predict with certainty how a court is likely to interpret such wording, it is preferable to set out in as much detail as possible the specific performance obligations, and limitations on the same.