Business Tax Deadline 2024 S Corporation. For partnerships and s corps it is march 15, 2024. Here’s what that means for your small business, any other deadlines you should be.

If you have structured your business as a class s corporation, you must file an extension by the 15th of the third month after the ending date of your tax year. There are two exceptions to the april 15 tax deadline — the due date for partnerships and s corporations to file their business return is march 15, 2024.