There is no clear law on the subject. In short, the order in which a contract is signed has no bearing on its legal status. However, it may be best for you to sign the contract last. That is why: In a legal and technical sense, an offer is made when the buyer signs the contract and delivers it to the seller. The seller has the option of modifying it, refusing it or accepting it. If the seller accepts it and signs it, the contract becomes binding. If the seller signs first and the buyer rejects the contract, the first contract must be returned before issuing a second one. This is the legal and technical point of view. Let's go back to the simplicity of a service contract. A contract, as stated earlier, requires an agreement. No one is bound by a contract which has been modified after its issuance. So if you sign a contract and send it to the buyer, the buyer can make changes, but they are not legally binding until you countersign them. In reverse, it's the same thing. If both parties agree, contracts can be exchanged quickly and the order is not critical.