- 01May 1, 2020
- 15May 15, 2020
- 15May 15, 2020
- 25May 25, 2020
- 26May 26, 2020
A=ANNUAL
M=MONTHLY
Q=QUARTERLY
DISCLAIMER: THESE DUE DATES ARE SUBJECT TO CHANGE. WE WILL DO OUR BEST TO KEEP THIS CALENDAR UP TO DATE WITH THE EVERCHANGING DEADLINES. ANY STATE FILING DUE DATES ARE IN REFERENCE SPECIFICALLY TO THE WASHINGTON STATE DEPARTMENT OF REVENUE.