The California Transfer Tax Affidavit (San Mateo) is a document used to report and pay transfer taxes in San Mateo County, California. It is used for the transfer of real property, such as a house, land, or business. This document must be completed and signed by both the buyer and the seller of the property to show that the transfer tax has been paid. There are two types of California Transfer Tax Affidavit (San Mateo): the Residential Transfer Tax Affidavit and the Commercial Transfer Tax Affidavit. The Residential Transfer Tax Affidavit is used when transferring a residential property, while the Commercial Transfer Tax Affidavit is used when transferring a commercial property. Both forms require information such as the address of the property being transferred, the purchase price, and the names of the buyer and seller. The documents must also be notarized, and all applicable taxes must be paid before the transfer can be completed.