what is the irs publication 15 
irs publication 15 employer s tax guide is a document published by the internal revenue service detailing an employer s responsibilities for filing and reporting tax information the document covers the withholding depositing reporting paying and correcting of taxes for employees although not for the corporation itself irs publication 15 is also referred to as circular e 1 understanding irs publication 15irs publication 15 is used to determine federal income tax but not state or local taxes the tax guide details federal income tax amounts for payroll withholdings including medicare and social security amounts 2 employers should refer to their state s tax rules to ensure that proper state income tax amounts are withheld from employees paychecks extra tax information is also available in irs publication 15 a 3 previously one of the most important features contained in the employer s tax guide was the percentage method tables and wage bracket method tables for income tax withholding 4 however for the 2020 employer s tax guide these withholding tables have been removed these tables and the employer instructions on how to figure employee withholding are now included in publication 15 t federal income tax withholding methods the irs also provides an assistant on their website called the income tax withholding assistant for employers to help employers figure out employee withholding 5 these wage bracket tables help an employer to know exactly which percentage of their employees payroll they should be withholding for taxes every pay period in order to comply with federal tax regulations in order to determine the tax withholding amount an employee must also file a w 4 form which can be updated as situations change in the employee s life such as a new family member 6 in the event that an employee does not file a w 4 the employer s tax guide also details what amount to withhold instead 7 