Evaluating Washington's Ballot Rejection Rates

Washington is one of a few states that votes entirely by mail. Indeed, election officials cite several advantages of voting by mail. For example, voters find it convenient and flexible. It reduces or eliminates long wait times in polling places. In addition, it can increase voter turnout.

The Washington State Legislature mandated a performance audit of ballot rejection rates in a proviso to the 2020 Supplemental Budget. Legislators expressed concerns about the state’s ballot rejection rate. They also raised the possibility that rates varied between counties and different groups of Washington voters.

The audit had several requirements, including:

  • Reviewing processes for identifying, curing and rejecting ballots
  • Comparing county processes to laws, leading practices and to each other
  • Examining the accuracy of ballot rejections
  • Analyzing the demographics of voters whose ballots were rejected

Finally, legislators asked the State Auditor's Office to make recommendations to improve processes around ballot rejections.

Read a two-page summary of the report.

Explore a booklet of leading practices identified during the audit.

Report Number 1029711 Report Credits

Key results

While we identified disparities in ballot rejection rates between counties and between certain demographic groups, our analysis found few patterns to explain those disparities. We did not find evidence of bias in the decisions made by elections workers. However, because we could not identify a pattern of behavior, we are unable to explain what causes rejection rates to vary for various groups of voters.

One takeaway from this audit is that we overwhelmingly concurred with counties’ decisions about which ballots to accept and which to reject. In addition, for the 10 counties we looked at, all met state requirements related to signature verification.

Furthermore, we found all audited counties met ballot processing and curing requirements. Most of them met drop box requirements as well.

In fact, all audited counties went beyond requirements and used a variety of leading practices. We compiled many of these and other innovative tactics into guidance for all Washington counties to use as they consider improving their election practices.


Washington’s counties carry out elections, with support and guidance from the Secretary of State. County election officials mail active voters a ballot about three weeks before the election. Voters have until Election Day to complete a ballot, sign the return envelope and return it.

Election officials must ensure that they count only valid votes. They reject ballots for three main reasons:

  • Received or postmarked after Election Day
  • Missing the voter’s signature on the ballot envelope
  • Voter signature cannot be confirmed

Of these, only the latter two can be “cured” by election officials. They do this by reaching out to voters with problematic or missing signatures.

Rejected ballots by county

The likelihood a ballot was rejected was highly correlated with the county where it was cast. We conducted a detailed statistical analysis of ballots submitted for the 2020 general election in Washington. Based on our analysis, the county where a voter cast their ballot was the most significant variable related to ballot rejection. We reached this conclusion after first accounting for demographic factors like age, race, education levels and income. Following that, we could estimate that ballots submitted to some counties were four to seven times more likely to be rejected than ballots submitted to other counties.

Auditors also reviewed a random sample of more than 7,200 signatures on ballot envelopes. Auditors agreed with county determinations for more than 98 percent of the signatures reviewed. From this, we concluded that ballots appear to have been accepted or rejected appropriately. However, we also found that counties with lower rejection rates were more likely to accept less conclusive signatures.

Trainings and statewide criteria may help standardize processes. Nonetheless, human judgment plays a significant role in confirming voter signatures.

Rejected ballots by demographics

Other demographic attributes were also highly correlated with ballot rejection. For example, we found a statistically significant difference in ballot rejection rates between white voters and voters from other racial and ethnic groups. (This did not include Native Americans and multiracial voters, likely due to low population counts for these voters.) Ballots from the following demographic groups were more likely to be rejected:

  • Younger voters
  • Male voters
  • Voters belonging to certain racial and ethnic groups

Researchers suggest possible explanations for higher ballot rejection rates. For example, younger voters might lack familiarity with voting processes. This might include not understanding the importance of a consistent signature or how to submit ballots properly. In addition, some ethnic groups might face language barriers in English, causing them to make more mistakes on the ballot. They may then have more trouble curing those mistakes.

We did not find evidence of bias in our analysis of ballots rejected by audited counties.

Meeting state law

Audited counties met all state laws regarding ballot processing and curing requirements. They also met other basic state requirements, such as:

  • Used the statewide election administration system, VoteWA
  • Opened a voting center 18 days before an election; at least one center was accessible to people with disabilities
  • Formed advisory committees, which address issues such as how to make voting more accessible, particularly for people with disabilities.

Finally,  all counties required to establish student engagement hubs did so.

However, three of the 10 audited counties did not have the legally required number of ballot drop boxes. (The required number changed in 2019, when a new state law related to drop box placement went into effect.) Officials offered several reasons why their counties lacked the legally required number of ballot drop boxes. Some said that they consider the new requirement an unfunded mandate. Some also said the new law’s specificity requires them to install boxes in areas where they might not be needed. One county noted that it has been working steadily towards meeting the mandate, even before it came into effect.

Using leading practices

In addition to meeting most legal requirements, audited counties implemented many leading practices to help reduce ballot rejections. We noted that all counties regularly conducted some informal outreach to keep voters informed about vote-by-mail processes. Additional practices include:

  • Develop and enact a formal outreach plan to better target voter education needed in that county
  • Review a signature more than once before officially challenging it
  • Contact voters with challenged ballots using a variety of methods, such as email and text messages
  • Use a variety of media to reach voters. Possibilities include:
    • Social media
    • Television
    • Mailed voter pamphlets
    • Direct outreach
    • Community partnerships

Adopting additional leading practices currently used by some counties may help lower rejection rates and increase cure rates elsewhere in Washington.

Innovative practices

The audit also found that counties could consider other practices to reduce ballot rejection rates. These practices — some innovative, others already in use elsewhere — could offer counties ways to reduce disparities among counties and among demographic groups. Although Washington’s elections may benefit from innovative practices, officials must first consider current regulations, available resources and voter needs.

The practices include strategies to:

  • Ensure voters know the status of their ballots
  • Reduce reliance on signatures to confirm identity
  • Make it easier to cure a challenged ballot and ensure voters understand the ballot review processes

In addition, we noted practices that may help counties manage operational processes around elections. These could help them manage costs as well as close gaps in voting access.


We made a series of recommendations to all Washington counties to reduce the number of rejected ballots. When implementing these recommendations, counties should weigh current laws and the resources available to them. They must also consider any potential effects on voters. As counties address their practices, we recommend they develop written policies and procedures to help ensure consistency between election cycles.

Specific recommendations include:

  • Giving voters more information about election rules and requirements
  • Improving efforts to reach voters with challenged ballots
  • Tracking information about efforts the counties make so they can determine effectiveness
  • Increasing the number of voter signatures they collect and keep on file