It's not a contract until the seller agrees to it and signs it. Some of the most important points in your offer are;.Offer and Acceptance. In the state of Arizona, no contract for real estate exists until the contract is offered and accepted in writing (A. You are legally bound to honor the agreement. Once both seller and buyer has an executed contract, we are now in escrow process. Some agents will ask you to sign something called a buyer's agent agreement before they start showing you homes. Sellers often wait to see if more attractive offers come in, especially in competitive markets. " But, you can accept or counter an offer that's expired.