Wisconsin Filing Due Date: WI individual income tax returns are due by April 15, in most years.

Extended Deadline with Wisconsin Tax Extension: Wisconsin offers a 6-month extension, which moves the filing deadline from April 15 to October 15.

Wisconsin Tax Extension Form: Wisconsin does not have its own separate extension application. If you have an approved Federal tax extension (IRS Form 4868), you will automatically receive a Wisconsin tax extension. If you do not have a Federal extension, you can file a copy of your Federal Form 4868 or a written statement explaining that you’d like to use the Federal extension provision.

Wisconsin Extension Payment Requirement: A tax extension gives you more time to file. It does not give you extra time to pay your Wisconsin income tax. All state tax payments are due by the original deadline of the return. Any WI tax that isn’t paid by the proper due date will be subject to interest and penalties. You can make a Wisconsin extension payment with Form 1-ES, or pay electronically using My Tax Account: tap.revenue.wi.gov/services