Hello, first of all, the contract is valid with or without the seal of the intermediary. However, when handling the transfer procedures of second-hand housing transactions, two situations are distinguished:

First through the intermediary, then the intermediary must participate, the buyer and the seller and the intermediary go to the trading center to sign the contract, and the intermediary seals the column of real estate agent to assist the whole process.

The other is that the relationship between buyers and sellers is decided by themselves, and no intermediary is needed. This situation is usually called "hand in hand" customers, as long as buyers and sellers go to the trading center to sign contracts, no intermediary is needed.

If it belongs to the second category, you can handle it with confidence.