Risk-Limiting Audits

In Washington, each county conducts a post-election audit after every election. A risk-limiting audit (RLA) uses statistics to confirm election outcomes. An RLA helps verify that the apparent winner of an election actually won. 

In a risk-limiting audit, ballots are randomly selected for review. Ballots are hand-tallied one by one until enough have been sampled to confirm that the correct winner was found the first time. If the winner won by a lot of votes, the sample needed to confirm the outcome may be quite small; if the race was close, the audit will examine more ballots.

The risk limit for statewide risk-limiting audits (RLAs) is 5%.

The risk limit for county-level ballot comparison RLAs is 5%.

The risk limit for county-level ballot polling RLAs is 10%.

2024 April Special Election

County Audit Date Target Contest Files
Spokane 4/30/2024 FIRE DISTRICT NO. 9 Proposition No. 1 Audit Board Report
Snohomish 4/30/2024   Audit Board Report
King 5/1/2024   Audit Board Report
Mason 5/1/2024 Fire Protection Dist. 16 EMS Levy Audit Board Report

Random seed dice roll: Friday, 4/26/2024, 3pm (https://youtube.com/live/hSYKQ2HN2go?feature=share)

Random seed: 36610420433612108066


2024 February Special Election

2023 General Election

2023 Primary

2023 April Special Election

2022 General Election

2022 Primary


RLA 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