Cal. Rev. & Tax. Code § 7098

For the purposes of this part only, the board shall not revoke or suspend a person’s permit pursuant to Section 6070 or 6072 unless the board has mailed a notice preliminary to revocation or suspension which indicates that the person’s permit will be revoked or suspended by a date certain pursuant to that section. The board shall mail the notice preliminary to revocation or suspension to the taxpayer at least 60 days before the date certain.