During the administration of President George W. Bush, there was a controversy over the President's use of signing statements, which critics charged was unusually extensive and modified the meaning of statutes.
Wisconsin Filing Due Date: Corporation tax returns are due by March 15 â or by the 15 th day of the 3 rd month following the end of the taxable year (for fiscal year filers). Extended Deadline with Wisconsin Tax Extension: If you have an approved Federal tax extension (IRS Form 7004), your Wisconsin filing deadline will be automatically extended to 30 days past the Federal extension deadline.
If you don't file an amendment form, then the Wisconsin Department of Revenue will do it for you, but you will have to pay interest on the unpaid tax. In Wisconsin you are allowed to file an amended return and get a refund within a period of 4 years since the original due date of the tax return.