Resources
Tax forms, deadlines and checklists
The forms people ask for most, the dates that matter, and what to gather before tax season.
Common forms
Official PDFs, straight from the IRS.
- Form W-9. Request for taxpayer ID. Collect one from every vendor or subcontractor before you pay them.Download
- Form W-4. Employee's withholding certificate. Every new employee fills one out.Download
- Form 4868. Extension for your personal return. It extends the time to file, not the time to pay.Download
Federal deadlines
Washington excise returns are due on the 25th of the following month for monthly filers, at the end of the month after each quarter for quarterly filers, and April 15 for annual filers.
- ThursdayExtended personal returns
Last day to file a 2025 Form 1040 if you filed an extension in April.
- FridayFourth quarter estimated tax
Final 2026 estimated payment for the self employed and anyone without enough withholding.
- MondayW-2s and 1099-NEC
Due to workers and to the IRS. January 31 falls on a Sunday, so the deadline moves to Monday.
- MondayPartnership and S corporation returns
Forms 1065 and 1120-S for calendar year businesses, plus K-1s to owners.
- ThursdayPersonal and C corporation returns
Form 1040, Form 1120, and the first 2027 estimated payment. Extensions available.
Personal return checklist
- Last year's return
- W-2s from every employer
- 1099s: interest, dividends, contract work, retirement, Social Security
- Mortgage interest (Form 1098) and property tax statements
- Charitable gift receipts
- Childcare costs and the provider's tax ID
- Marketplace health insurance form (1095-A) if you had one
- Records of any stock or property you sold
Small business habits that pay off
- Categorize income and expenses every month
- Reconcile bank and card accounts monthly
- Keep receipts for mileage, home office, software and supplies
- Collect a W-9 before paying any vendor, and file 1099s on time
- Log large equipment purchases for depreciation or Section 179
- Pay estimated taxes in April, June, September and January
- Ask for help before year end, when planning can still make a difference