Are you the Seller? It all depends on what the contingency period agreed to in the contract is. If nothing was altered and you used the California DRE Purchase Agreement, then there is a 17 day contingency period for the BUYER in which they could cancel. If you are the Seller, you are bound to the contract. You cannot cancel unless the Buyer does not perform on one of their contingency periods. Even then, you must issue a "Notice to Perform" and is also based on what is in the contract... Again, if unchanged, the notice allows 2 days for the buyer to perform. As you seller, once you agree and sign the contract, unless you were under the influence of something, under duress or forced to sign (you would need legal representation at that point) you are bound to sell this property. Good luck.