• Filing taxes can involve large amounts of paperwork.tax forms image by Chad McDermott from Fotolia.com
  
  You must file taxes in Wisconsin by April 15 of the year following the tax year. If you need an extension, you must apply for a federal extension. By obtaining an extension to file your federal tax return, you'll also be granted an extension to file your Wisconsin state tax return. Keep in mind that just because you have an extension does not mean you do not have to pay any taxes owed by the original deadline.
  
  

Filing for an Extension

• To obtain an extension to file your Wisconsin state tax return, you must file for an extension for your federal tax return. To do so, fill out and submit a Form 4868. You can obtain this form at the IRS website. Once you have filed this document, you have a six-month extension to file both your federal and Wisconsin state tax returns.
  
  

Automatic Extension - Outside the Country

• If you are outside of the United States or Puerto Rico on the original deadline to file your taxes, April 15, you will receive an automatic two-month extension. You do not need to file for this extension. Attach a statement to your Wisconsin state return explaining that you were out of the country on April 15.
  
  

Other Extensions

• Even if you do not need an extension to file your federal tax return, you qualilfy for other circumstances by which the IRS allows a federal extension. For example, the IRS allows for an extension for those serving in a combat zone or a qualified hazardous duty area. The IRS also allows for an extension when you are out of the country when the six-month extension expires. To qualify for an extension to file your Wisconsin state tax return under these provisions, fill out a Form 4868 and attach it to the state return.
  
  

Penalties

• If you take an extension to file your Wisconsin state tax return and it is determined that you owe taxes, as opposed to getting a refund, you will have to pay an interest rate of 1 percent per month on the amount of the tax liability. If you need an extension, but know you will owe taxes, file an estimated tax return and pay the estimated tax liability to avoid be charged interest. You are exempt from this penalty if you served in Operation Iraqi Freedom or a similar combat zone.