First and foremost, Force Majeure has no recognised meaning in English law. Its inclusion into English contracts is to excuse one or both parties from the performance of the contract in some way following the occurrence of certain events which are usually beyond either of the parties’ control. However, to be effective, those events need to be properly defined in order to add certainty to the agreement. It is not sufficient to simply say that a party will be excused from complying with its obligations if a Force Majeure event takes place. For example, in British Electrical and Associated Industries (Cardiff) Ltd v Patley Pressings Ltd  1 WLR 280 a clause stating that the “usual Force Majeure clauses shall apply’ was considered void and was therefore unenforceable.
Given the importance that such clauses can have on a contract, the drafting of a list of events that might be considered Force Majeure can be both cumbersome and lengthy. What might be considered outside of the parties’ control to one party might not be considered as such by the other party.
That is why it is important to have express inclusion or exclusion of certain events when a contract is being drafted. The party most likely to seek to rely on a Force Majeure clause (generally the supplier of goods or services) will want to ensure that any eventuality is covered so that they do not end up bound by the terms of a contract that they may find difficult complying with if compliance is even possible.
Whereas, the party least likely to enforce the clause will want to omit as many events as possible so that it can either enforce the terms of a contract if a specific event is not covered or alternatively sue for any loss suffered if the contract cannot be performed.
Where a party seeks to rely on a Force Majeure clause, the burden of proof falls on them to prove that the event falls within any defined clause in the contract and that specific event is the reason for non-compliance. It is not sufficient to rely on a defined event for failure to comply when the reason that the contract has not been honoured is for completely unrelated reasons.
Even further, the Force Majeure event must be the sole reason why the contract has not been honoured. This proposition was established in Intertradex v Lesieur  2 Lloyd’s Reports 509 and was upheld in Seadrill Ghana v Tullow Ghana where Teare J found that the defendant’s failure to provide drilling instructions to the claimant, a contractual obligation, was caused by two matters; one a Force Majeure event, the other not. As the Force Majeure event was not the sole reason for failing to comply with the terms of the contract then the contract remained binding and enforceable.
Further, it is not sufficient to simply rely on a Force Majeure event as reason for not complying with your contractual obligations if it cannot be shown that the party seeking to rely on the clause has used reasonable endeavours to prevent, or at least mitigate the effects of the Force Majeure. This means, for example, a party should consider whether there are any other ways that the contract can be complied with even if it falls outside of the scope of what is contractually obligated to do.
Once a Force Majeure clause has been relied upon by one party and it is accepted that they are contractually entitled to rely upon that clause, what does it mean for the performance of the contract? For the most part, clauses are suspensory so that the obligations do not fall away, they are simply put on hold until such time as the contract can be performed.
If compliance of the contract makes no commercial sense after the Force Majeure event has passed then either party may serve notice terminating the agreement after a specified period of time if the contract allows for such a notice to be served. Once a Force Majeure clause has come into effect and the contract has either been suspended or terminated, the non-performing party will not be liable for any non-performance or delay unless they were already in breach at the time of the Force Majeure event.