Small Business Tax Deadlines Calendar (Federal and Washington)

Missing a deadline is one of the most common and most avoidable ways small businesses waste money. Here's a year-at-a-glance calendar for a typical calendar-year business in Washington. When a date falls on a weekend or holiday, it usually moves to the next business day.

January

• January 15: 4th quarter federal estimated tax payment (for the prior year)
• January 31: Forms W-2 to employees and the Social Security Administration
• January 31: Forms 1099-NEC to contractors and the IRS
• January 31: Form 940 (federal unemployment) and Q4 Form 941 for employers
• January 31: Washington Q4 excise tax return for quarterly filers (monthly filers' December return is due January 25)
• January 31: Q4 Washington employer reports (unemployment insurance, Paid Family and Medical Leave, workers' comp)

February / March

• February 28 (paper) / March 31 (electronic): Form 1099-MISC to the IRS
• March 15: S-corporation (Form 1120-S) and partnership/multi-member LLC (Form 1065) returns, or file an extension
• March 15: Deadline for an S-corp election to apply to the current year for many existing businesses

April

• April 15: Individual returns (Form 1040), including sole proprietors and single-member LLCs (Schedule C), or file an extension
• April 15: C-corporation (Form 1120) returns for calendar-year corporations
• April 15: 1st quarter federal estimated tax payment
• April 15: Washington annual excise tax return (for annual filers)
• April 30: Q1 Form 941 and Washington employer reports

June

• June 15: 2nd quarter federal estimated tax payment

July

• July 31: Q2 Form 941 and Washington employer reports

September

• September 15: 3rd quarter federal estimated tax payment
• September 15: Extended S-corp and partnership returns due

October

• October 15: Extended individual and C-corp returns due
• October 31: Q3 Form 941 and Washington employer reports

Monthly and quarterly Washington excise taxes

The Department of Revenue assigns each business a filing frequency:

• Monthly filers: generally due on the 25th of the following month
• Quarterly filers: generally due at the end of the month after the quarter ends
• Annual filers: generally due April 15 of the following year

Check your My DOR account for your exact schedule.

Your LLC's annual report

Washington LLC and corporation annual reports are due by the end of your formation anniversary month. This date is different for every business, so put yours on the calendar.

Business license renewal

Your Washington business license and city endorsements renew on your assigned expiration date.

How to never miss one

• Put every date into a shared calendar with reminders two weeks ahead
• Keep books current monthly so returns can be filed on time
• Work with a bookkeeper who tracks compliance dates for you

The bottom line

Most penalties come from missed dates, not complicated tax law. Build your calendar once, and review it every January.

---

Need help getting this right? TRIG Bookkeeping & Tax Services helps new business owners in Washington with company registration, monthly and annual bookkeeping, and government compliance. Contact us to talk about your business.

This article is general information, not legal or tax advice for your situation. Tax rules and fees change, so confirm current details with the IRS, the Washington Department of Revenue, or a qualified professional.