Cal. Code Regs. tit. 22 § 4320-1
An employer required to deduct and withhold income taxes of other states, political subdivisions of such states or the District of Columbia from wages paid to a resident of California (as defined in Section 17014 of the Revenue and Taxation Code) shall deduct and withhold from those wages the amount of California personal income tax determined under the applicable withholding method provided for in regulations prescribed by the Franchise Tax Board under Section 18663 of the Revenue and Taxation Code, less the amount required to be deducted and withheld from those wages under the laws, rules and regulations of such other states, political subdivisions of such states or the District of Columbia.
EXAMPLE (1). A resident of California is paid weekly by an employer required to deduct and withhold from his or her wages California and Maine income taxes, and the amount required to be withheld under the respective weekly wage bracket tables is $3.40 for California and $2.50 for Maine. Therefore, the amount of California tax required to be deducted and withheld is $.90.
EXAMPLE (2) A resident of California is paid weekly by an employer required to deduct and withhold from his or her wages California and New York income taxes, and the amount required to be withheld under the respective weekly wage bracket tables is $3.40 for California and $6.80 for New York. Therefore, no California tax is required to be deducted and withheld.
Cal. Code Regs. Tit. 22, § 4320-1
Note: Authority cited: Sections 305 and 306, Unemployment Insurance Code. Reference: Section 13020, Unemployment Insurance Code.