I'm not sure what state you are from, but in NY, any offers can fall through, as long as Contracts have not been signed. You just let your agent know that you are rescinding the offer, and they will pass on the information to the seller. . . Do NOT, i repeat, do NOT just "disappear". It is very inconsiderate, because each day you don't let them know you are pulling out of the transaction is a day they are unable to find someone else to buy their house. Always stay professional. I work in the real estate industry here, and customers like that have a difficult time finding agents in the future to work with. Word spreads really fast.