Extension Deadline HQ
Two dates matter for extension filers: September 15 (calendar-year S corporations and partnerships) and October 15 (individuals and C corporations). Everything you need to hit them is on this page.
The calendar file carries reminders a week and a day before each deadline. No email address required.
The document checklist
Gathering these this week is the difference between an October of review and an October of archaeology:
- Every monthly statement for every business account (checking, savings, cards), covering the full year
- Last year's tax return (the baseline your preparer starts from)
- Mileage log, home-office facts, and receipts for large equipment purchases
- 1099s received, and the payee list for any 1099s you owe others
- A reconciled year-to-date P&L (the piece this site exists for)
The last item is the slow one when the books are behind, and the fast one here: upload the year's statement PDFs and a reconciled P&L comes back in minutes, typically about $130 for a full year, checked to the penny or refunded.
The guides
What the extended individual deadline actually requires, the calm timeline, and the mistakes that cost money.
The earlier wall: extended 1120-S and 1065 returns, per-owner penalties, and why K-1s hold up personal returns.
The complete handoff checklist, and the one document that stalls everything when it's missing.
Reconstructing a year of income and expenses from statements, organized the way the form expects.
Online archives, closed accounts, and the balance-chain test that proves your set is complete.
Free, in your browser: catches scans, password protection, and oversized files. Nothing is uploaded.
Written by a licensed CPA. General information, not tax advice; deadlines can shift for weekends, holidays, and federally declared disasters, so confirm your dates with your preparer. © 2026 RapidPnL LLC.