Most appeal deadlines
Most, but not all, appeals to the Board of Tax Appeals must be filed within 30 days from the mailing date of the decision or determination being appealed.
- Your deadline may be different, depending on the type of appeal.
- Deadlines for each appeal type are listed in WAC 456-09-315 and 456-10-315.
IMPORTANT: We have no authority to extend these deadlines or accept a late appeal. No ongoing discussions or extensions granted by the county board, Department of Revenue, or any other agency will extend your deadline with us.
Calculate your appeal deadline
If your deadline falls on a Saturday, Sunday, or legal holiday, you have until the next business day to file your appeal.
Count the deadline carefully. Some months have more than 30 days, so the deadline may not fall on the same date in the next month. For example, if an order or decision is dated May 18, your appeal is due by June 17.
You can use the calculator below to find your 30-day appeal deadline.
Next steps
Learn about how to prepare for your hearing.