In Reveille Independent LLC v Anotech International (UK) Ltd [2016] EWCA Civ 443, the Court of Appeal considered whether a provision requiring both parties to sign a document for it to be legally binding could be waived by conduct.  Reveille had proffered a 'Deal Memo' which had to be signed by both parties to be binding. Anotech altered, signed and returned the document, thus making a counter-offer.  Anotech later sought to argue that no agreement was in place, because Reveille had not signed the amended document.  At first instance, the judge concluded that Reveille had not properly signed the Deal Memo, but had accepted by conduct the counter-offer in the amended document, a decision appealed by Anotech.  On Appeal, Mr Justice Cranston found that the Deal Memo amended by Anotech constituted a counter-offer which required acceptance. By not signing it, Reveille as offeree was waiving the proscribed method of acceptance.  As Anotech was receiving the benefit of Reveille's performance of the Deal Memo's terms, it was not in any way prejudiced by the waiver.  There was also clear evidence of Reveille's acceptance of the offer by conduct, of which Anotech was aware.  The court therefore decided that Reveille did waive the provision that there would be no binding contract in the absence of its signature on the Deal Memo. There was no prejudice from this to Anotech. There was acceptance by conduct on Reveille's part of the terms of the Deal Memo, leading to a binding contract.  Accordingly the appeal was dismissed. To read more please click here.