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 February Special Election

County Audit Date Target Contest Files
Cowlitz 2/20/2024 Longview School District No. 122 Proposition 1  
Thurston 2/20/2024 North Thurston Public School Proposition No. 1  
King 2/21/2024 City of Renton Initiative 23-02  
Mason 2/21/2024 Mason County Emergency Communication Systems (9-1-1) Sales and Use Tax Audit Board Report
Whatcom 2/21/2024 Bellingham School District Proposition 2024-13 Audit Board Report

Random seed dice roll: held Friday, 2/16/2024, 3pm (https://www.youtube.com/watch?v=FOQnZOFmEDI)

Random seed: 79541744442971905955


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