RTS Flexible Systems Ltd v Molkerei Alois Müller GmbH & Co KG

Whether a binding contract has been concluded, and on what terms, is determined objectively from the parties' words and conduct, not their subjective states of mind; parties may by their conduct waive a 'subject to contract' stipulation and become bound, even though a formal contract is never signed, once they have agreed all terms they (or the law) regard as essential.