Who Must Act as an Iowa Withholding Agent?
Every employer who maintains an office or transacts business in Iowa and who is required to withhold federal income tax on any compensation paid to employees for services performed in Iowa is required to withhold Iowa individual income tax from that compensation. The amount withheld is calculated using the Iowa withholding tables, formulas or percentages.
Registering as an Iowa Withholding Agent
After obtaining a FEIN, register with Iowa.