File this form if you want to: Request approval to have an agent file returns and make deposits or payments of Federal Insurance Contributions Act (FICA) taxes, Railroad Retirement Tax Act (RRTA) taxes, income tax withholding (ITW), or backup withholding; or Revoke an existing appointment. Current revision Form 2678 PDF Instructions for Form 2678 PDF Recent developments Corrected mailing addresses for Form 2678 -- 20-JUNE-2024 Other items you may find useful All Form 2678 revisions About Publication 15, (Circular E), Employer's Tax Guide Other current products Related items About Form 940, Employer's Annual Federal Unemployment (FUTA) Tax Return About Form 941, Employer's Quarterly Federal Tax Return About Form 941-SS, Employer's Quarterly Federal Tax Return - American Samoa, Guam, the Commonwealth of the Northern Mariana Islands, and the U.S. Virgin Islands About Form 943, Employer's Annual Federal Tax Return for Agricultural Employees About Form 944, Employer's Annual Federal Tax Return About Form 945, Annual Return of Withheld Federal Income Tax About Form CT-1, Employer's Annual Railroad Retirement Tax Return About Form CT-2, Employee Representative's Quarterly Railroad Tax Return