Today is the day! If you need more time to file your business income taxes, you must file IRS Form 7004 to avoid penalties. Tax extension Form 7004 is an automatic extension used to file business tax returns for partnerships (Form 1065), C-Corps (Form 1120), S-Corps (Form 1120S), Multi-Member LLCs, Trusts, and Estates.Click here to e-file before the deadline at midnight today!