For overpayments: Employers correcting an overpayment must use the corresponding "X" form. 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.Bystep explanation on how to fill out Form 941. An upclose review of how to complete and file Form 941, including when it's due and why it's essential. Get Payroll Tax Services. Enter this balance owed on line 14.