The return of second-hand mortgage is a violation of economic contract and needs to bear liquidated damages.

Repaying the second-hand mortgage is liable for breach of contract.

There are several ways to bear the liability for breach of contract:

(1) Pay liquidated damages.

(2) Compensation for damages.

(3) continue to perform.

See if the property owner and the contractor have legal authorization procedures. According to the usual practice, under normal circumstances, if the property owner can't sign a contract with the actual purchaser, he should go to the notary office for authorization and notarization, and clearly authorize the contractor to sign the contract, transfer the property right, collect the house payment, deliver the house and other matters of the seller. Otherwise, this kind of contract is invalid or its effectiveness is to be determined, and the buyer has the right to terminate the contract and ask the contractor to bear the liability for compensation.