Adams County property tax appeal 2027: deadline, forms and how to file
To appeal an Adams County assessment, file with the Adams County Board of Equalization by mail or in person; in Washington the deadline is July 1 or 30 days after the Change of Value Notice is mailed, whichever is later (60 days in some counties, such as King). Confirm the exact date on your notice or with the assessor; we add each county's 2027 date here when it is published.
Assessors mail a notice when a value changes, never between January 15 and February 15 (RCW 84.40.045); revaluation notices go out on each county’s schedule and state the appeal deadline.
Data as of 20 Oct 2026 · Adams County Board of EqualizationCheck your own assessment
Free. We compare the value on your notice with recent sales of similar homes nearby and tell you whether an appeal is worth filing. Have your assessment notice and tax bill handy.
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How to file in Adams County
- Step 1
File the appeal
Use the method your notice lists, usually Form 64 0075, by the deadline on the notice.
- Step 2 · before the hearing
Prepare and submit your evidence
The assessor’s value is presumed correct; you need specific market evidence that it is wrong (WAC 458-14-046). “Taxes are too high” or a large percentage increase is not enough. Use comparable sales from the last five years, adjusted to January 1 (sales closest to that date count most), a recent appraisal, photos and repair estimates (WAC 458-14-087). Ask the assessor for the comparable sales it used; it must provide them at least 21 business days before your hearing, and new evidence from either side is due 21 business days before it (WAC 458-14-066).
- Step 3
Meet, then hear
An talk to the assessor with County Assessor comes first; if you decline the offer, the Adams County Board of Equalization hears the case. Most reductions happen at the first step.
Before you file: how to read your notice · evidence that works · informal vs formal hearing · when not to appeal
Forms
| Form | Number | Use | Format |
|---|---|---|---|
| Taxpayer Petition to the County Board of Equalization for Review of Real Property Valuation Determination | 64 0075 | The statewide petition. Give your opinion of value and the market evidence behind it; attach the notice if you file after July 1. | |
| Informal Property Tax Appeal (Board of Tax Appeals) | — | Only if you appeal the county board’s decision to the State Board of Tax Appeals. Attach the board’s order. |
Appeal levels
| Level | Who hears it | Deadline | Cost |
|---|---|---|---|
| Talk to the assessor | County Assessor | Any time; it does not extend the petition deadline | Free |
| Board of Equalization | Adams County Board of Equalization | July 1, or 30–60 days after the notice, whichever is later | Free |
| Board of Tax Appeals | Washington State Board of Tax Appeals | 30 days after the county board’s decision is mailed | Free |
What evidence the board accepts
The assessor’s value is presumed correct; you need specific market evidence that it is wrong (WAC 458-14-046). “Taxes are too high” or a large percentage increase is not enough. Use comparable sales from the last five years, adjusted to January 1 (sales closest to that date count most), a recent appraisal, photos and repair estimates (WAC 458-14-087). Ask the assessor for the comparable sales it used; it must provide them at least 21 business days before your hearing, and new evidence from either side is due 21 business days before it (WAC 458-14-066).
Adams County questions
When is the Adams County appeal deadline for 2027?
July 1 of the assessment year, or 30 days after your value notice was mailed (up to 60 days where the county has extended it), whichever is later (RCW 84.40.038). Check the deadline printed on your value notice.
How do I appeal my assessment in Adams County?
Send petition Form 64 0075 (or the county’s approved version) to the Adams County Board of Equalization.
What evidence does the board accept?
Market evidence: comparable sales from the last five years adjusted to January 1, a recent appraisal, photos and repair estimates. The assessor’s value is presumed correct, and saying taxes are too high is not grounds for a change.
Can I see the assessor’s comparable sales?
Yes. Ask the assessor; it must give you the sales and valuation data it used at least 21 business days before your hearing (WAC 458-14-066). Your own new evidence is due by the same point.
How do I contact the Adams County Assessor's Office?
Phone: 509-659-3236. Hours and walk-in details: co.adams.wa.gov.
What if I disagree with the board’s decision?
Appeal to the State Board of Tax Appeals within 30 days after the board’s decision is mailed. There is no filing fee, and late appeals are dismissed.
Check whether yours is over-assessed
Nearby counties
Franklin County · Lincoln County · Whitman County · Grant County · Walla Walla County · Columbia County · Garfield County
- Adams County Board of Equalization
- Adams County Assessor
- Adams County Board of Commissioners (phone)
- DOR: Appealing Your Property Assessment to the County BOE (hosted by Adams County)
- RCW 84.40.038 — Petition to the county board of equalization
- RCW 84.40.045 — Notice of change in valuation
- WAC 458-14-066 — Exchange of valuation information
- WAC 458-14-087 — Evidence of value
- RCW 84.08.130 — Appeals to the Board of Tax Appeals
- Washington DOR — Appeal my property assessment
- Board of Tax Appeals — Residential property appeals
- U.S. Census Bureau, county population estimates (2024) and county gazetteer (2024).