CT-1

Employer's Annual Railroad Retirement Tax Return

Agency
IRS
Revision
2025
Fillable fields
80
Pages
3
Official source
IRS form page
Checked
October 21, 2026
Fill CT-1 online
Page 1 of form CT-1

Form CT-1: Employer's Annual Railroad Retirement Tax Return

Form CT-1 is used to report taxes imposed by the Railroad Retirement Tax Act (RRTA). The instructions say to file it if you paid one or more employees compensation subject to tax under the RRTA, and that federal income tax withheld from employees' wages and other compensation is reported on Form 941 or, if applicable, Form 944 instead.

The 2025 form has Part I, Railroad Retirement Taxes, with lines 1 to 12 for the Tier 1, Tier 1 Medicare, Tier 1 Additional Medicare, and Tier 2 taxes on compensation and sick pay, followed by the total, adjustments, deposits, balance due, and overpayment. Part II is the record of railroad retirement tax liability for monthly schedule depositors. Page 3 holds Form CT-1(V), the payment voucher.

The employer, or a payer of sick pay, completes and signs it. You can fill out Form CT-1 free in your browser on this page and download it without an account.

What's on Form CT-1

Heading

Name, employer identification number, address, RRB number, and a box to check if this is a final return.

Lines 1 to 7: tax on compensation

Compensation times the printed rate for each tax: Tier 1 Employer 6.2%, Tier 1 Employer Medicare 1.45%, Tier 2 Employer 13.1%, Tier 1 Employee 6.2%, Tier 1 Employee Medicare 1.45%, Tier 1 Employee Additional Medicare 0.9%, and Tier 2 Employee 4.9%.

Lines 8 to 12: sick pay

The Tier 1 employer, employee, Medicare, and Additional Medicare taxes on sick pay, at the same printed rates.

Lines 13 to 18e: totals and payment

Total tax, adjustments for fractions of cents and other items, total taxes, deposits for the year, balance due, and overpayment with the choice to apply it to the next return or have it refunded by direct deposit.

Part II: Record of Railroad Retirement Tax Liability

A monthly summary of Tier 1 and Tier 2 tax liability by quarter, completed only by monthly schedule depositors when line 15 is $2,500 or more.

Signature, designee and voucher

Third-party designee, signature, and paid preparer areas on page 1, then Form CT-1(V), Payment Voucher, on page 3.

How to fill out Form CT-1

  1. 1

    Lines 1 to 3

    Enter compensation other than tips and sick pay, multiply by the rate, and enter the tax. The instructions say lines 1 and 8 combined may not be more than $176,100 per employee, and line 3 takes no more than $130,800 per employee.

  2. 2

    Lines 4 to 7

    Include tips reported by employees. For 2025 the instructions say Tier 1 Employee tax stops at $176,100, Tier 1 Employee Medicare tax has no limit, Additional Medicare withholding applies above $200,000, and Tier 2 Employee tax covers the first $130,800.

  3. 3

    Line 14

    Enter a fractions of cents adjustment, credits for overpaid penalty or interest from earlier years, and uncollected employee tax on tips. The instructions say prior period adjustments go on Form CT-1 X, and a statement explains any adjustment other than fractions of cents.

  4. 4

    Lines 16 to 18

    Line 16 is total deposits, including overpayments applied from Form CT-1 X or the 2024 return. If line 15 is larger, the difference goes on line 17; if line 16 is larger, on line 18a. The instructions say never to make an entry on both.

  5. 5

    Part II or Form 945-A

    If line 15 is less than $2,500, Part II and Form 945-A are skipped. Monthly schedule depositors fill Part II, and line V equals line 15. Semiweekly schedule depositors, or those who accumulated $100,000 or more on any day in a deposit period, use Form 945-A instead.

  6. 6

    Sign

    The instructions list who signs: the owner of a sole proprietorship, a principal officer of a corporation, a responsible partner, member, or officer, the owner of a single-member LLC, or the fiduciary of a trust or estate. An authorized agent with a valid power of attorney may also sign.

Why fill Form CT-1 on indox

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Where it goes, deadlines and payments

Where to file

The instructions say to send Form CT-1 to Department of the Treasury, Internal Revenue Service Center, Kansas City, MO 64999-0048.

When to file

The instructions for the 2025 form say to file Form CT-1 by March 2, 2026.

Deposits by EFT

The form says federal tax deposits are made by electronic funds transfer, through EFTPS or an IRS business tax account. Form CT-1(V) is not used for deposits.

Paying with the return

The voucher says to pay with the return only when line 15 is less than $2,500 and paid in full with a timely return, or as a monthly schedule depositor under the accuracy of deposits rule. A check is made payable to United States Treasury with the EIN, Form CT-1, and 2025 on it.

Final return

Check the final return box and attach a statement with the last date compensation was paid, where the records will be kept and who keeps them, and any transferee's name, address, and date of transfer.

Corrections and address changes

The instructions say errors on a filed Form CT-1 are corrected on Form CT-1 X, which is filed separately, and an address change uses Form 8822-B.

Related forms

Who files Form CT-1?

  • Employers paying RRTA compensation

    Employers that paid one or more employees compensation subject to tax under the RRTA. The instructions say employers pay both Tier 1 and Tier 2 taxes and withhold the employee part from compensation.

  • Payers of sick pay

    A payer of sick pay, including a third party, files Form CT-1 if the sick pay is subject to Tier 1 railroad retirement taxes, reporting it on lines 8 to 11 and, if the withholding threshold is met, line 12.

  • Returning filers

    After the first Form CT-1, the instructions say a return is filed for each year, even if no taxable compensation was paid, until a final return is filed.

  • Disregarded entities and QSubs

    Eligible single-owner disregarded entities and qualified subchapter S subsidiaries are treated as separate entities for employment tax purposes and report using their own names and EINs.

  • Paid preparers

    A paid preparer who isn't an employee of the filing entity signs the Paid Preparer Use Only section. The instructions say a reporting agent with a valid Form 8655 on file generally doesn't complete it.

The instructions say to file Form CT-1 if you paid one or more employees compensation subject to tax under the RRTA. The terms employer and employee are defined in section 3231.

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Questions about Form CT-1

Does Form CT-1 report federal income tax withholding?

No. The instructions say to use Form 941 or, if applicable, Form 944 to report federal income taxes withheld from employees' wages and other compensation.

What rates are printed on the 2025 Form CT-1?

6.2% for Tier 1 employer and employee tax, 1.45% for Tier 1 Medicare, 0.9% for Tier 1 Employee Additional Medicare, 13.1% for Tier 2 Employer, and 4.9% for Tier 2 Employee.

Is a return filed in a year with no compensation?

The instructions say that after the first Form CT-1, a return is filed for each year, even if no taxable compensation was paid, until a final return is filed.

Which deposit schedule applies?

It depends on line 15 for the lookback period, the second calendar year before. For 2026, the instructions say $50,000 or less in 2024 means a monthly schedule depositor, and more than $50,000 a semiweekly schedule depositor.

Are employer taxes due on tips?

The instructions say employers don't pay employer railroad retirement taxes on tips, but employee railroad retirement tax is collected on cash tips employees report.

Can someone else talk to the IRS about the return?

Yes, through the Third-Party Designee section, with the designee's name, phone number, and any five digits they choose as a PIN. The instructions say the authorization expires 1 year from the return's due date, without regard to extensions.