1. Whether the signature of the couple selling the house by the intermediary is valid or not depends on the situation:

(1) If the house is jointly owned by husband and wife, the house sales contract signed by one husband and wife without the consent of the other is invalid;

(2) However, if a third person obtains the house in good faith, the house purchase and sale is valid for the third person. If the third party pays a reasonable consideration in good faith and the house has been delivered or registered for transfer, the contract is not only valid, but should continue to be performed if it has not been delivered or transferred.

2. Legal basis: Article 38 of People's Republic of China (PRC) Urban Real Estate Management Law.

The following real estate shall not be transferred:

(a) the acquisition of land use rights by means of transfer does not meet the conditions stipulated in Article 39 of this Law;

(two) the judicial organs and administrative organs have ruled or decided to seal up or restrict the real estate rights in other forms according to law;

(three) to recover the land use right according to law;

(four) without the written consent of other people, * * * owns real estate;

(five) the ownership is controversial;

(6) Failing to register according to law and obtaining the ownership certificate;

(seven) other circumstances in which the transfer is prohibited by laws and administrative regulations.

Article 628 of the Civil Code of People's Republic of China (PRC)

The buyer shall pay the price at the agreed time. If there is no agreement or the agreement is unclear, and it cannot be determined according to the provisions of Article 510 of this Law, the buyer shall pay at the same time as receiving the subject matter or taking out the subject matter documents.

2. What are the procedures for selling a house?

1. The buyer and the seller sign a house sales contract;

2. The buyer and the seller shall handle the house transfer registration at the registration institution where the real estate is located;

3. The housing registration agency where the real estate is located shall review the materials, and handle the registration of ownership transfer if it meets the requirements.