Post-Election Audits
In Washington, each county conducts a post-election audit after every election.
There are two types of post-election audit conducted in Washington:
Random Batch Audit
A random check of ballot counting equipment, commonly known as a random batch audit, compares a hand count of ballots to the voting system count in selected batches or precincts. This check occurs within 48 hours of election day. (RCW 29A.60.170)
Random Ballot Audit
A random ballot audit, also known as a risk-limiting audit (RLA), uses statistics to help verify election outcomes. This check provides evidence that the apparent winner of an election actually won.
Ballots are randomly selected for review, then compared to the voting system record. If the winner won by a lot of votes, the sample needed to help verify the outcome may be quite small; if the race was close, the audit will examine more ballots.
The risk limit for statewide ballot comparison risk-limiting audits (RLAs) is 5%.
The risk limit for county-level ballot comparison RLAs is 5%.
2026 April Special Election: Random Ballot Audits
| County | Audit Date | Target Contest | Audit Report |
|---|---|---|---|
| Mason | 05/05/2026 | NORTH MASON SCHOOL 403 - Replacement of Educational Programs and Operations Levy | Audit Board Report (PDF) |
| San Juan | 05/06/2026 | San Juan County Proposition No. 1 | Audit Board Report (PDF) |
Random seed: 39744 29253 75663 23522 (PDF)
Watch the 2026 April Special Random Seed Dice Roll
Random ballot audit software certification
Arlo Approval for Use - Certification (PDF)
Additional resources
RCW 29A.60.185 - Audit of results.
WAC Chapter 434-261 - Sections 114-119 on risk-limiting audit procedures.
risklimitingaudits.org - Additional resources and RLA academic papers