Employers in Iowa must conform with these state rules relating to income tax withholding and administration.
General Withholding Requirement: Iowa income tax must be withheld from wages paid to resident employees for services performed either within or without the state and from wages paid to nonresident employees for services performed in the state. However, when resident employees are subject to another state's withholding tax, Iowa tax is to be withheld from their wage payments only to the extent it exceeds the other state's withholding tax on the same wages.
Employee Withholding Exemption Forms: Iowa Form IA-W4 may be completed by each employee, to determine the appropriate level of state income tax to withhold from earnings, or the federal form can be substituted for state purposes. Of course, Federal Form W-4 also must be completed by each employee, to determine the appropriate level of federal income tax to withhold from earnings.
Reciprocal Agreements: Iowa has a reciprocal agreement in effect with Illinois.
Administration:
Iowa Department of Revenue
Withholding Tax Processing
Hoover State Office Building
P.O. Box 10411
Des Moines, Iowa 50306-0411
Telephone: 515-281-3114