Illinois Tax 245 is a tax program established by the Illinois Department of Revenue. It is designed to help taxpayers complete their Illinois Individual Income Tax return. There are two types of Illinois Tax 245: the original version, and the e-file version. The original version allows taxpayers to complete their Illinois Individual Income Tax return using physical forms or through an online form. The e-file version allows taxpayers to use the Department of Revenue's online e-file system to submit their return. Both versions require taxpayers to provide their Social Security number, filing status, income, and other relevant information.