REVENUE AND TAXATION CODE section 23037
23037. "Taxpayer" means any person subject to the tax imposed under Chapter 2 (commencing with Section 23101), Chapter 2.5 (commencing with Section 23400), or Chapter 3 (commencing with Section 23501).
Inapplicability of the Term "Taxpayer"
The term "taxpayer" is defined in Section 23037 to mean any person responsible for paying taxes. A disregarded entity is not responsible for paying taxes, and therefore the "taxpayer" under Section 23101(d) cannot also be a disregarded entity.