Calendar-year individuals on extension have until October 15, 2026 to file a 2025 return, while pass-through entities on extension face an earlier September 15, 2026 date, and extended trusts and estates on Form 1041 are due September 30, 2026.
For retail and CPG business owners who filed extensions in April, the September 15 deadline for S-corporations, partnerships, and multi-member LLCs is less than two weeks away. The October 15 deadline for individual returns, including Schedule C sole proprietors and the owner-level return for any pass-through, follows closely. An extension moved the return, not the payment. Any balance for 2025 was due at the original April deadline, and interest plus a late-payment penalty have been accruing since.
If your 2025 business return is on extension and not yet filed, this is the week to make it a priority.