Option 1: Pay all or some of your Wisconsin income taxes online via: Wisconsin Department of Revenue.
Option 2: If you owe WI income taxes, you will either have to submit a WI tax return or extension by the tax deadline in order to avoid late filing penalties. You can only eFile and IRS tax extension, but not a Wisconsin extension. The tax extension will only avoid late filing penalties until the October deadline.
Note: Unless you pay all your Taxes or eFile your tax return by the October deadline, the late filing penalties will start again after that deadline. If you expect to pay additional taxes owed, you can avoid the 1% per month interest charge during the extension period by paying the tax you will owe by the tax deadline.
Option 3: Complete Form 1-ES, include a Check or Money Order, and mail both to the address on Form. Important: Even if you filed an extension, you will still need to file your WI tax return either via eFile or by paper by the October deadline.