On the perils of relying on oral instructions.

Party A was a sub-contractor, and Party B was a sub-sub-contractor. Under the contract, Party B could only carry out variation works if it received written instructions from a designated person. Party B claimed that it had carried out variation works that had been orally requested, and sought payment from Party A. The High Court dismissed Party B's claim.

Regardless of whether you have such a clause in your contract, get instructions in writing. While "a gentleman's word is his bond", as Party B argued, (a) a verbal agreement is not worth the paper it is written on; and (b) not all contracting parties are gentle(wo)men.