Corporations and S Corporations must file and pay their federal income taxes by March 15. Not April 15. Maybe this is one advantage to having a limited liability company, partnership, or sole proprietorship, because they are not required to pay taxes until April 15. If you think you will not be able to file by the March 15 deadline, you can file an extension on IRS Form 7004,which will give you until September 15 to file.
BUT even if you file an extension, you must still estimate the tax you owe and pay that tax by March 15. There's no extension on payment.
Of course, if you have been paying estimated taxes, you will have paid most of your federal income taxes. Now it's time to complete your corporate tax return and pay any balance due. But don't tackle that corporate tax return yourself; you will need a competent tax preparer to do this work.
For more information on preparing your corporate income tax return, see my Corporate Income Tax Return Guide. It includes information on filing for an extension, paying estimated taxes, and more.
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