About

Business Deadline Check explains federal filing dates for Form 1065, Form 1120-S, and Form 1120, and it runs a checker for those dates in the browser.

The publisher is the site itself. There is no named person, no firm, and no tax designation behind these pages. The site is not the Internal Revenue Service and is not affiliated with it. The pages do not imitate IRS.gov.

What you will find

A deadline checker, and guides drawn from IRS instructions, Publication 509, Treas. Reg. 1.6072-2, Rev. Proc. 2025-32, and Rev. Proc. 2013-30, read on 17 October 2026. A re-check is planned for 1 January 2027. Where a point is open, the page says so. The open point kept in view is whether a Form 7004 extension moves the Schedule K-1 date.

The late-filing amount used for Form 1065 and Form 1120-S is $260 per partner or shareholder per month for returns filed in 2027, under Rev. Proc. 2025-32. Check the current IRS amount. Calendar-year Form 1120 dates of 15 April 2027 and 15 October 2027 are expected too. All 2027 dates are labelled expected.

What you will not find

• A state deadline, a state form, or a state penalty.
• Affiliate links, sponsored placements, or a claim that a product is approved by the IRS.
• Accounts, saved calculations, or a request that you identify yourself in order to read.
• The foreign-books timing rule. It is omitted.