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Form CT1: Employer's Annual Railroad Retirement Tax Return
IRS Form CT-1 is Employer's Annual Railroad Retirement Tax Return, used to report taxes imposed by the RRTA for a calendar year. For 2025, direct deposit of the refund is available.
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IRS Form CT1 - Employer's Annual Railroad Retirement Tax Return
IRS Form CT-1 is Employer's Annual Railroad Retirement Tax Return, used to report taxes imposed by the RRTA for a calendar year. For 2025, direct deposit of the refund is available.
Risk Radar
Scan points- 1Failing to determine the correct deposit schedule based on the lookback period is critical for filing correctly.
- 2Filing without determining the correct deposit schedule for the current year.
- 3Failing to complete Part II if the entity was a monthly schedule depositor.
- 4Not completing Form 945-A when required (semiweekly or $100k+ accumulation).
- 5Omitting the Preparer Tax Identification Number (PTIN) for paid preparers.
Plain English
This form allows an employer to officially tell the IRS how much railroad retirement tax was collected during the entire year. It summarizes these taxes paid on employee compensation and helps fulfill reporting requirements alongside other federal tax forms. Filing this confirms compliance with the Railroad Retirement Tax Act (RRTA).
Submission Date
- Filing date: 2026-01-14 17:26:06
- Preparation window: collect IDs, supporting records, and signatures in advance.
- Final review: verify names, dates, and required fields before submission.
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What this form is for
- Use this form when reporting taxes imposed by the Railroad Retirement Tax Act (RRTA).
- Do not use it when reporting federal income taxes withheld from employee wages, as Form 941 or Form 944 are used for that.
- Check Form CT-1 X instead when correcting a previously filed Form CT-1.
Form selector
Use this form or another form?
Need to correct an error on a prior filing
This form is filed separately from the main return.
✓ Verify instructions for Form CT-1 X.
Making a payment by check or money order
Use this voucher when paying your balance due via paper methods.
✓ Ensure you enclose it with Form CT-1.
Paying the balance due by EFT instead of mailing in a voucher
If using EFT, do not file Form CT-1(V).
✓ Confirm payment method before sending.
None (Use address from Instructions)
Deadline or filing window
The required timing depends on the lookback period, which is the second calendar year preceding the current one. For example, to file for 2026, the lookback period is 2024. The form must be filed according to the schedule determined by taxes reported on Form CT-1 line 15 from that lookback period.
Checklist
What you need before filling it out
Purpose of Form CT-1
Use Form CT-1 to report taxes imposed by the RRTA. · Instructions p.2
Filing Deadline
File Form CT-1 by March 2, 2026. · Instructions p.3
Where to Send
Department of the Treasury Internal Revenue Service Center Kansas City, MO 64999-0048 · Instructions p.3
Direct Deposit Availability
Direct deposit of Form CT-1 refund is now available (per EO 14247). · Instructions p.1
Payment Method Options
EFT, check, or money order are acceptable for line 17 payment. · Instructions p.8
Overpayment Calculation (Line 18a)
Enter the difference if Line 16 is more than Line 15 on Line 18a. · Instructions p.8
Before you submit
- 1Verify that all compensation paid to employees in the preceding year was reported (implied by purpose).
- 2Confirm that if group-term life insurance over $50,000 was provided, its cost is included in compensation.
- 3(Instructions p.3)
- 4Ensure this amount is also on the employee's Form W-2.
- 5Medium
- 6Check that federal tax deposits were made by electronic funds transfer (EFT) if using EFTPS/business account.
- 7(Instructions p.2)
- 8If paying via check/money order, confirm you are using Form CT-1(V).
- 9(Form p.3)
- 10High
- 11Verify that the payment amount on Line 17 is correctly calculated before submitting.
- 12(Instructions p.8)
How to file this form
- 1Complete all sections of Form CT-1, ensuring compensation details and tax amounts are accurately reported as per the instructions.
- 2If paying by check or money order, complete Form CT-1(V) and enclose it with Form CT-1. If paying via EFT, do not file Form CT-1(V).
- 3Determine your payment method: Pay Line 17 using EFT (via EFTPS/business account), check, or money order.
- 4Mail the completed Form CT-1 (and enclosed Form CT-1(V) if applicable) to the IRS Center in Kansas City, MO 64999-0048 before March 2, 2026.
Known limitations
- 1The term "compensation" includes payment for time lost as an employee, with exceptions described later under Exceptions.
- 2Group-term life insurance costing over $50,000 provided to an employee is included in compensation but is subject to Tier 1 and Tier 2 taxes, not federal income tax withholding.
- 3When paying the balance due by EFT, Form CT-1(V) should not be used for filing; instead, use the address listed under Where To File.
- 4If an amount is paid with Form CT-1 but should have been deposited, the filer may be subject to a penalty.
Field map
Compact field-by-field guide
Employer Info
1 items
Full legal name and Employer Identification Number.
Quarter
1 items
Select the calendar quarter this return covers.
Wages
1 items
Sum of all wages, tips, and other compensation paid to employees during the quarter.
Withholding
1 items
Total federal income tax withheld from employee paychecks.
SS & Medicare
1 items
Wages subject to Social Security tax (capped) and Medicare tax (uncapped).
Deposit
1 items
Indicate your deposit schedule: monthly, semiweekly, or next-day rule if over $100k.
Signatures
1 items
Must be signed by an authorized officer or agent of the employer.
Almost done reviewing the fields?
Fillable formOpen in Editor->The current edition is 20/25, and for the latest information regarding Form CT-1, filers should consult IRS.gov/CT1. Changes noted include that direct deposit of the Form CT-1 refund is now available due to Executive Order (EO) 14247.
What changed or needs a fresh check
- Edition date — confirm revision reads 20/25.
- Filer definition — confirm 'employer' and 'employee' are defined per section 3231 of the Internal Revenue Code.
- Mailing address — confirm the center is Kansas City, MO 64999-0048.
- Signature — state that signing is required before sending (implied by general instructions).
- Payment details — confirm if paying via check/money order, make it payable to 'United States Treasury'.
- Tax year reference — confirm the tax year referenced on payment methods is 2025.
Quick Facts
Downloads
After you file
- 1Retain a copy of the filed Form CT-1.
- 2If you receive a failure-to-deposit (FTD) penalty notice, respond within 90 days of the date of the notice.
- 3When responding to an FTD penalty notice, designate how your payment is to be applied to minimize the penalty by following the instructions on the notice.
- 4For the 2026 filing, use the total taxes reported on Form CT-1 for the lookback period (which is calendar year 2024) to determine the deposit schedule.
Sources
- SRCInstructions p.1 — The instructions are for Form CT-1 Employer’s Annual Railroad Retirement Tax Return.
- SRCInstructions p.1 — For 2025, direct deposit of the Form CT-1 refund is available due to Executive Order (EO) 14247.
- SRCInstructions p.2 — The purpose of Form CT-1 is to report taxes imposed by the RRTA.
- SRCInstructions p.2 — To report federal income taxes withheld, use Form 941 or Form 944.
- SRCInstructions p.3 — Compensation includes payment in money for services performed as an employee and includes payment for time lost as an employee.
- SRCInstructions p.6 — If you receive a failure-to-deposit (FTD) penalty notice, you must respond within 90 days of the date of the notice.
Common confusion points
What defines "compensation"?
Compensation means payment in money for services performed as an employee, and it includes payments for time lost.
When should I use Form CT-1(V)?
Use Form CT-1(V) when paying your balance due by check or money order. Do not use it to make a general federal tax deposit.
What is the "lookback period"?
The lookback period is the second calendar year preceding the current calendar year (e.g., for 2026, the lookback period is 2024).
Where do I send Form CT-1?
Send it to: Department of the Treasury Internal Revenue Service Center Kansas City, MO 64999-0048.
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Questions about IRS Form CT1
What is IRS Form CT1 used for?
This form allows an employer to officially tell the IRS how much railroad retirement tax was collected during the entire year. It summarizes these taxes paid on employee compensation and helps fulfill reporting requirements alongside other federal tax forms. Filing this confirms compliance with the Railroad Retirement Tax Act (RRTA).
Who must file IRS Form CT1?
Employers must file Form CT-1 to report taxes imposed by the RRTA.
What information does IRS Form CT1 require?
The form collects details about the railroad retirement taxes paid, and if applicable, requires completing Part II for monthly schedule depositors. It also allows for reporting via Form 945-A if the entity is a semiweekly schedule depositor or accumulated $100,000 or more on any day during a deposit period.
When is IRS Form CT1 due?
The filing timing is determined by the lookback period; before each year begins, the deposit schedule must be determined based on taxes reported for the second calendar year preceding the current one.
Where do I file IRS Form CT1?
Form CT-1 can be filed electronically via direct deposit for refunds, and it may also be signed by a duly authorized agent if a valid power of attorney has been filed.
How do I complete IRS Form CT1?
The filer completes Form CT-1, ensuring proper Part II completion if applicable (e.g., monthly schedule depositor). Corporate officers or authorized agents can sign using a rubber stamp, mechanical device, or computer software program. A paid preparer must complete the Paid Preparer Use Only section in Part I and provide their PTIN.
What happens if IRS Form CT1 is filed incorrectly?
Penalties are provided for failure to file or late filing/payment unless the delay is due to reasonable cause and not willful neglect. Interest is charged on taxes paid late at the rate set by law.
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