Mailing addresses for Forms 941 ; Department of the Treasury Internal Revenue Service Kansas City, MO 64999-0005. Internal Revenue Service PO Box 806532When I did the 4th qtr 941 I had an overpayment. But when I run the 1st qtr report it does not pull forward, How do I fix it to show up? This guide provides the basics of the 941 form, instructions to help you fill it out, and where you can get help meeting all your payroll tax obligations. On or before the last day of January each year, every employer who has withheld tax during the preceding year must file Form. As an employer, you must record sums that are withheld from employee wages in a ledger account to clearly indicate the amount of state tax withheld.