Is There a Deadline for Filing Form CT-1 X?

Generally, you may correct overreported taxes on a previously filed Form CT-1 if you file Form CT-1 X within 3 years of the date Form CT-1 was filed or 2 years from the date you paid the tax reported on Form CT-1, whichever is later. You may correct underreported taxes on a previously filed Form CT-1 if you file Form CT-1 X within 3 years of the date the Form CT-1 was filed. We call each of these time frames a period of limitations. For purposes of the period of limitations, Form CT-1 is considered filed on the last day in February of the succeeding year if filed before that date.

Example. You filed your 2022 Form CT-1 on January 30, 2023, and payments were timely made. The IRS treats the return as if it were filed on February 28, 2023. On January 15, 2026, you discover that you overreported RRTA compensation on that form by $10,000. To correct the error, you must file Form CT-1 X by March 2, 2026 (February 28, 2026, is a Saturday), which is the end of the period of limitations, and use the claim process.

If you file Form CT-1 X to correct overreported tax