Before You Begin

Complete your federal income tax return Form 1040, U.S. Individual Income Tax Return, or Form 1040-SR, U.S. Tax Return for Seniors, before you begin your Form 540, California Resident Income Tax Return. Use information from your federal income tax return to complete your Form 540. Complete and mail Form 540 by April 15, 2025. If unable to mail your tax return by this date, see " Important Dates " at the beginning of these instructions. Also, see “ Interest and Penalties ” section for information regarding a one-time timeliness penalty abatement.

Tip : You may qualify for the federal earned income credit. See " $$$ for You " at the beginning of the booklet for more information.

Note : The lines on Form 540 are numbered with gaps in the line number sequence. For example, line 20 through line 30 do not appear on Form 540, so the line number that follows line 19 on Form 540 is line 31.

Caution : Form 540 has six sides. When filing Form 540, you must send all six sides to the Franchise Tax Board (FTB) and Side 6 must be signed.

If you need to amend your California resident income tax return, complete an amended Form 540 and check the box at the top of Form 540 indicating AMENDED return. Attach Schedule X, California Explanation of Amended Return Changes, to the amended Form 540. For specific instructions, see “ Instructions for Filing a 2024 Amended Return .”

To use our automated phone service and codes, call 800-338-0505. For the complete code list, see " Automated Phone Service ".