S-Corp Tax Deadline 2025. September 15, 2025 | s corporation and partnership extended tax return deadline submit irs form 1120s or 1065 if your business operates on a calendar year and applied for an. If you need more time, you can request an.
Deadline to file form 2553 to switch your business entity to an s corporation (s corp) for tax year 2024. September 15, 2025 | s corporation and partnership extended tax return deadline submit irs form 1120s or 1065 if your business operates on a calendar year and applied for an.