Before the loan contract is signed, the mortgage contract is invalid. Because the mortgage contract, as a subsidiary contract of the loan contract, should be signed after both parties sign the main contract and determine the main rights and obligations. Therefore, the mortgage contract is invalid before the loan contract.

Legal basis: Article 566 of the Civil Code. If the contract has not been performed after dissolution, the performance shall be terminated. If it has been performed, according to the performance and the nature of the contract, the parties may request restitution or take other remedial measures, and have the right to claim compensation for losses.

Where the contract is terminated due to breach of contract, the creditor may request the breaching party to bear the liability for breach of contract, unless otherwise agreed by the parties.

After the termination of the main contract, the guarantor shall still be liable for the civil liability of the debtor, unless otherwise agreed in the guarantee contract.