Cal. Rev. & Tax. Code § 42110

(a) Notwithstanding Section 55381, it is unlawful for any person, other than an officer or employee of a county, city and county, city, or district, who obtains access to information contained in, or derived from, local charge records of the department pursuant to subdivision (b), to retain that information after that person’s contract with the county, city and county, city, or district has expired.
(b)
1. (1) When requested by resolution of the legislative body of any county, city and county, city, or district, the department shall permit any duly authorized officer or employee of the county, city and county, city, or district, or other person designated by that resolution, to examine all of the local charge records of the department pertaining to the ascertainment of those local charges to be collected for the county, city and county, city, or district by the department pursuant to contract entered into between the department and the county, city and county, city, or district pursuant to this part. Except as otherwise provided in this section, this subdivision does not allow any officer, employee, or other person authorized or designated by a county, city and county, city, or district to examine any sales or transactions and use tax records of any taxpayer. The costs that are incurred by the department in complying with a request made pursuant to this subdivision shall be deducted by the department from those revenues collected by the department on behalf of the county, city and county, city, or district making the request.
2. (2) The resolution of the legislative body of the county, city and county, city, or district shall certify that any person designated by the resolution, other than an officer or employee, meets all of the following conditions:
  1. (A) Has an existing contract with the county, city and county, city, or district to examine those local charge records.
  2. (B) Is required by that contract to disclose information contained in, or derived from, those local charge records only to an officer or employee of the county, city and county, city, or district who is authorized by the resolution to examine the information.
  3. (C) Is prohibited by that contract from performing consulting services for a seller during the term of that contract.
  4. (D) Is prohibited by that contract from retaining the information contained in, or derived from, those local charge records, after that contract has expired.
3. (3) Information obtained by examination of department records pursuant to this subdivision shall be used only for purposes related to the collection of the local charges by the department pursuant to the contract, or for purposes related to other governmental functions of the county, city and county, city, or district set forth in the resolution.
(c) If the department believes that any information obtained pursuant to subdivision (b) has been disclosed to any person not authorized or designated by the resolution of the legislative body of the county, city and county, city, or district, or has been used for purposes not permitted by subdivision (b), the department may impose conditions on access to its local charge records that the department considers reasonable, in order to protect the confidentiality of those records.
(d) Predecessors, successors, receivers, trustees, executors, administrators, assignees, and guarantors, if directly interested, may be given information as to the items included in the measure and amounts of any unpaid local charges or amounts of local charges required to be collected, interest, and penalties.