Revenue and Taxation Code § 18624

(a) Section 6109 of the Internal Revenue Code, relating to identifying numbers, shall apply, except as otherwise provided.

(b) Identifying numbers shall be required on state tax returns, statements, or other documents in the form and manner as the Franchise Tax Board may require.

(c) Section 6109(h) of the Internal Revenue Code, relating to identifying information required with respect to certain seller-provided financing, shall not apply.

(d) (1) For taxable years beginning on or after January 1, 2021, the Franchise Tax Board shall not require a nonresident alien who is not eligible for or has not been issued a federal social security number (SSN) or a federal individual taxpayer identification number (ITIN) to provide a SSN or ITIN in order to file a state tax return, statement, or other document required under this part. If a nonresident alien subsequently becomes eligible for and is issued a SSN or ITIN, the Franchise Tax Board may require the nonresident alien to provide a letter or other form documenting the nonresident alien’s SSN or ITIN.

(2) For purposes of this subdivision, “nonresident alien” shall mean a nonresident, as defined in Section 17015, who also meets the requirements of Section 7701(b)(1)(B) of the Internal Revenue Code.