The Internal Revenue Service does not allow taxpayers to file old taxes online; however some states do allow taxpayers to file their old returns electronically. Wisconsin for example allows taxpayers to file their tax returns from up to two years prior online. Filing late taxes online is the same as filing current tax returns online with the exception of the filing year. Old federal tax return forms are available to taxpayers online, but must be mailed to the Internal Revenue Service when complete.
Determine whether or not the state in which you reside allows taxpayers to file prior-year tax returns online. If your state does not allow old returns to be filed online you will need to find the tax form for the year in question, fill it out and mail it to the state's Department of Revenue.
Choose the “E-File” link on your state Department of Revenue Web page and choose the tax year you wish to file and the online tax provider with whom you will use to file your prior-year tax return.
Enter all of the required information and additional information you have for the tax year in question. If your return shows that you owe tax you will need to include your payment information for the Department of Revenue. If you are receiving a refund you have the option of entering your bank account information so your refund will be directly deposited into your bank account or having a paper check mailed to you. Submit your tax return to the Department of Revenue when you are finished by clicking on the “Submit” button.