The time when both buyer and seller commit themselves to the deal under a legally binding agreement. The seller's conveyancing solicitor draws up two copies of the same contract, and each party signs their own copy. When both parties are ready to legally commit, the two contracts are exchanged. This is a very important moment in the conveyancing process – as soon as contracts are exchanged, the seller must sell, the buyer must buy, and this must all be done at the price set out in the conveyancing contract. Until contracts are exchanged, nothing is binding and either party can walk away from the conveyancing transaction with no penalty.