1. ​ What is the deadline for filing my Wisconsin return?


2. What if my electronically-filed return is rejected on the due date of the return?


3. Am I subject to interest or penalties if I don't file my Wisconsin income tax return by the due date?


4. Will I be assessed a late filing fee if I qualify for an extension of time to file?

1. What is the deadline for filing my Wisconsin return?

   Your 2023 return must be filed by April 15, 2024, unless you have an extension of time to file.

   A paper return is considered filed by the due date if all three of the following conditions are met:

   • The return is mailed in a properly addressed envelope with the postage duly prepaid
   • The envelope containing the return is postmarked on or before the due date
   • The return is received by the Department of Revenue within five days of the due date
     
     

   If you file late without an extension, you are subject to penalties and interest.

   For information on obtaining a Wisconsin extension of time to file, see the Tax Filing Extensions for Paper and Electronically Submitted Returns Common Questions.

2. What if my electronically-filed return is rejected on the due date of the return?

   If an electronically-filed return is rejected, you must correct the errors and resubmit the return within five business days of the rejection for the return to still be considered timely (called the "perfection period").

3. Am I subject to interest or penalties if I don't file my Wisconsin income tax return by the due date?

   If your 2023 individual income tax return is not filed by April 15, 2024, you may be subject to the following charges:

   • Late-filing fee: $50
   • Delinquent interest: 1.5% per month (18% per year).
     Note: During an extension period, interest is charged at 1% per month (12% per year) on any unpaid tax due
   • Negligence penalty for failure to timely file: 5% per month of the tax required to be shown on the return, up to a maximum of 25%
   
   
4. Will I be assessed a late filing fee if I qualify for an extension of time to file?

   Wisconsin allows a 180-day extension period (same as for federal tax). You will not be assessed a late filing fee if you file within the extension period. You may be assessed interest if tax is due.

Applicable Laws and Rules

This document provides statements or interpretations of the following laws and regulations enacted as of January 11, 2024: secs. 71.03, 71.82 and 71.83, Wis. Stats., and sec. Tax 2.08, Wis. Adm. Code.

Laws enacted and in effect after this date, new administrative rules, and court decisions may change the interpretations in this document. Guidance issued prior to this date, that is contrary to the information in this document is superseded by this document, according to sec. 73.16(2)(a), Wis. Stats.

The department welcomes your input on our guidance. Submit comments on this guidance document.

Guidance Document Number: 100065

January 11​, 2024