Note: Some addresses may not match a particular instruction booklet or publication. This is due to changes being made after the publication was printed. This page will reflect the most current where to file addresses for use during calendar year 2024. Addresses for forms beginning with the letter C Form name (For a copy of form, instruction, or publication) Address to mail rorm to IRS CT-1, Employer's Annual Railroad Retirement Tax Return Department of the Treasury Internal Revenue Service Center Kansas City, MO 64999-0048 CT-1-X, Adjusted Employer's Annual Railroad Retirement Tax Return or Claim for Refund Department of the Treasury Internal Revenue Service Center Cincinnati, OH 45999-0007 CT-2, Employee Representative's Quarterly Railroad Tax Return Department of the Treasury Internal Revenue Service Center Kansas City, MO 64999-0049
