When are Forms 1040 and 1120 due?

Who must file

Use Form 1040, or Form 1040-SR, for an individual return. If you have a business or side income as a sole proprietor, file Form 1040 with Schedule C. A single-member LLC is, for income tax purposes, disregarded as separate from its owner unless it files Form 8832 and elects to be treated as a corporation. If the owner is an individual and the LLC operates a trade or business, its activities generally go on Schedule C of the owner's Form 1040.

Domestic corporations use Form 1120 to report income, gains, losses, deductions and credits, and to figure the tax. Unless an exemption applies, a domestic corporation must file Form 1120 whether or not it has taxable income. This map is for a calendar-year C corporation. A corporation with a fiscal year ending June 30 has a different due date, set out in the Form 1120 instructions.

The April 15, 2027 due date

The IRS states that the tax deadline for 2026 tax returns is April 15, 2027, and that April 15, 2027 is the deadline to file and pay. A corporation must file by the 15th day of the 4th month after its tax year ends, which is April 15 for a calendar-year Form 1120.

If a due date falls on a Saturday, Sunday or legal holiday, you may file on the next day that is not a Saturday, Sunday or legal holiday. A legal holiday here means a legal holiday in the District of Columbia. April 15, 2027 is a Thursday. The IRS pages checked for this map print April 15, 2027 as the deadline, with no later date.

Payment is due with the return

Payment for taxes you owe is due by the filing deadline even if you get a filing extension. Pay what you owe by April 15, 2027. Paying later adds interest and penalties.

Form 4868 and Form 7004

If you need more time to file a Form 1040, request an extension by the April due date. The IRS says this gives you until October 15 to file, and that the extension is only for filing your return. You may use Form 4868, or pay online and indicate that the payment is for an extension. An extension of time to file is not an extension of time to pay.

A C corporation uses Form 7004, filed by the regular due date, for an automatic 6-month extension of time to file Form 1120. For a calendar-year return due April 15, that extended filing date is October 15. October 15, 2027 is a Friday. Form 7004 does not extend the time to pay any tax due.

Late-filing and late-payment penalties

If you file late, the IRS charges 5% of the tax due, after amounts paid on time, for each month or part of a month, up to 25%. If you pay late, the failure-to-pay penalty is 0.5% of the unpaid tax for each month or part of a month, up to 25%. For a return required to be filed in 2027, the minimum late-filing penalty, if the return is more than 60 days late, is the lesser of $535 or 100 percent of the tax required to be shown on the return, from Rev. Proc. 2025-32 in Internal Revenue Bulletin 2025-45.

Common questions

Does my single-member LLC file its own income tax return?

Not if it is disregarded. Unless the LLC elects to be treated as a corporation, its trade or business activity generally goes on Schedule C of your Form 1040.

Does an extension give me more time to pay?

No. An extension of time to file is not an extension of time to pay. Pay what you owe by April 15.

Is this tax advice?

No. It is general information from IRS pages checked on November 13, 2026. Rules change, so check the sources before you act.