If you did not know by now, your United States C corporation 1120 federal tax return is due in April this year (2017) rather than March, assuming your business runs January through December. Note that I am not a CPA so I am not an expert on all things taxes, I just know that Illinois and the Federal Government made this deadline change in 2017. This does not mean that I am ready to file or pay, though I always have good intentions.
My main complaint with filing my 1120 is that it is busy work. While it might be my only federal tax return that I file for the corporation, it is certainly not the only filing I make during the year, or the only paperwork that needs to be done. I know, I know, the tax man needs his money, but it comes at the expense not only of cash, but of my time to do more financially productive things. Here is an idea of all the busy work you must do with a corporation: