First of all, consider whether the buyer and the seller collude to sign the contract, if so, the buyer obtains the ownership of the house; In the absence of collusion, among several buyers, the one who has gone through the registration formalities for the transfer of commercial housing property rights can obtain the ownership of the house before other buyers, and other buyers can demand the cancellation of the sales contract because the purpose of the contract cannot be realized, and demand the seller to bear the liability for breach of contract; If the buyer fails to go through the registration formalities, the buyer who has gone through the registration of the house sales contract has priority to obtain the ownership of the house.
Secondly, if the buyer fails to register the property right and file the contract, the legal owner of the house can get the ownership first.
In other cases, if the buyer fails to obtain the ownership of the house, the house can pay off the debt to the buyer in proportion after setting the price.