Ballot Processing and Election Security

Motor Vehicle, Elections, & Recording are open Monday -Thursday 7:30 a.m. – 5 p.m. and closed to the public on Friday. See press release for more details. Las divisiones de Vehículos de Motor, Elecciones y Registro están abiertas de Lunes a Jueves de 7:30am a 5:00pm, y cerradas al público los Viernes. Vea el Comunicado de Prensa para más detalles.

Ballot Processing & Election Security

Lifecycle of a Ballot

Ballot Processing Infographic

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24hr Ballot Box

Election Security Community Briefing

Published in the fall of 2020, this report provides details about Boulder County’s approach to elections security and the actions we are taking to protect your voter information and the integrity of your vote.

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Pre-election Testing of the Ballots and Equipment

Boulder County Elections prints ballots with a local vendor in order to oversee strict testing and quality control of the printing process. Our protocols go far beyond what is required by Secretary of State rule or state statute.

In addition to all the quality control we do onsite at the print facility, we are one of the only counties that uses live ballots during our pre-election testing of the ballots and equipment (every Colorado county performs a test called the Logic and Accuracy test before every election). This means we test vote on ballots pulled from the actual print run of ballots that will be mailed to voters, versus having the printer print a “separate test deck.” We then run the ballots through our scanners and use our voting system software to ensure everything is calibrated correctly and tabulating properly.

Examples of Ballot Printing Quality Control

Quality control processes conducted by Boulder County Election team members include (but are not limited to):

  • Ballot print alignment: Making sure all ballot styles are correctly printed, using a see-through mylar overlay to inspect every portion of the ballot and make sure all the text and target boxes are where they should be.
  • Checking print quality: Testing paper and print for ink adhesion, runs, smudges, etc.
  • Checking fold lines: Making sure ballot fold lines are where they should be.
  • Verifying ballot styles: Making sure the right ballot styles are being printed; that no files were mixed up/combined, etc.
  • Checking for accurate ballot insertion to the right voter: Checking batches of ballots to make sure voters are receiving the correct ballot style and inserts.

This quality control work is done at the printer, prior to further testing of the ballots at our office through the ballot processing and voting system equipment.

Voting System Security

Our voting system is the equipment and software used to create ballots, capture votes, and tabulate results. The voting system we use is­­ called Dominion, one of the Colorado Voting Systems selected by the state after a rigorous public input process.

The voting system is not connected to the internet and there are no updates to the voting system once the “trusted build” is applied. The trusted build is the vendor software that is tested and certified by the Secretary of State’s office for election use.

Electronic voting machines

Boulder County does not use electronic voting machines (formerly referred to as DRE machines). Beginning in 2017, we do have “ballot marking devices.” These are available for any voter to use, and support accessible voting for disabled voters. The voter verifies their ballot choices onscreen, then prints a paper ballot and deposits the voted ballot into a secure ballot box before leaving the Voter Service and Polling Center. Only physical, paper ballots are used and counted in Boulder County.

Post-election Audit of the Election Results

To ensure voting system tabulation accuracy, a statewide risk limiting audit is conducted after each election. The process reviews how a ballot’s votes were captured at the time it was processed by comparing a sample of paper ballots with digital tallies. To learn more about the Colorado risk-limiting audit process, see this Politico story on the implementation, or this Colorado Public Radio story, or this fact sheet from the Colorado Secretary of State.

Elections Videos

Signature Verification Process

Mail Ballot Security

Elections Tour – Short Version

Elections Tour – Extended Version

Services at a Vote Center

Contact Us

Elections Division


303-413-7728 (Fax)


**New as of Jan 4, 2021**
7:30 a.m. – 5:00 p.m. Mon-Thurs.
CLOSED Fridays


Boulder: 1750 33rd Street
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Longmont: 529 Coffman Street
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Lafayette: 1376 Miners Drive
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Mailing Address

1750 33rd Street, Suite 200
Boulder, CO 80301