If the owner buys a first-hand commercial house, there are three signatures, which are respectively signed by the buyer on the last page of the commercial house sales contract signed with the developer, at the seam pressing place where the annex of the contract is attached with the floor plan, and at the supplementary contract buyer on the back of the contract. If the owner buys and sells second-hand houses, there are two signatures, specifically in the blank space of the seller's or buyer's contract text on the first page of the signed second-hand house sales contract and the blank space of the seller's or buyer's signature on the last page of the contract.

If the owner buys a first-hand commercial house, there are three signatures, which are respectively signed by the buyer on the last page of the commercial house sales contract signed with the developer, at the seam pressing place where the annex of the contract is attached with the floor plan, and at the supplementary contract buyer on the back of the contract. If the owner buys and sells second-hand houses, there are two signatures, specifically in the blank space of the seller's or buyer's contract text on the first page of the signed second-hand house sales contract and the blank space of the seller's or buyer's signature on the last page of the contract.