Cal. Rev. & Tax. Code § 7055

In administration of the use tax the board may require the filing of reports by any person or class of persons having in his or their possession or custody information relating to sales of tangible personal property the storage, use, or other consumption of which is subject to the tax. The reports shall be filed when the board requires and shall set forth the names and addresses of purchasers of the tangible personal property, the sales price of the property, the date of sale, and such other information as the board may require.