How voting works in Colorado
Registration, ID, early and mail voting, drop boxes and how many people voted each way in 2024, from official sources.
In Colorado, ID is required to vote in person; same-day registration is permitted; early in-person voting begins 15 days before Election Day for general elections; every active registered voter is mailed a ballot. In 2024, 91.3% of the ballots cast in Colorado came by mail.
Registering to vote in Coloradoonline, automatic and same-day registration
| Topic | Colorado | All states |
|---|---|---|
| Online registration | OVR permitted | 42 states and D.C. have online voter registration |
| Automatic registration | AVR permitted | 24 states and D.C. have automatic voter registration |
| Pre-registration | 15, 16 and 17-year-olds may preregister | 23 states and D.C. permit pre-registration for 16- and 17-year-olds |
| Same-day registration | Permitted | 24 states and D.C. have same-day registration |
| Registration deadline | 8 days before Election Day to receive mail ballot | National average is 19 days before Election Day |
| Voter registration database | Top-down | 36 states and D.C. use top-down; six states use bottom-up; eight states use a hybrid system |
Register or check your registration on the federal portal: Vote.gov, Colorado.
Casting a ballot in ColoradoID, early voting, mail ballots and drop boxes
| Topic | Colorado | All states |
|---|---|---|
| ID to vote in person | ID required | 36 states require ID to vote in person |
| Early in-person voting | Begins 15 days before Election Day for general elections | 47 states and D.C. allow early in-person voting; national average is 21 days |
| Vote centers on Election Day | Vote centers are used | 21 states and D.C. allow vote centers for Election Day voting |
| Absentee voting without an excuse | Permitted; ballots are mailed to all active registered voters | 36 states permit no-excuse absentee voting |
| Ballots mailed to every voter | Ballots are mailed to all active registered voters | Eight states and D.C. mail ballots to all active registered voters |
| Deadline to return a mail ballot | 7 p.m. on Election Day | 36 states require ballots returned by Election Day* |
| Who may return another person's ballot | A voter’s designee (anyone), or qualified election official | 38 states have laws governing ballot collection |
| Ballot drop boxes | Permitted | 12 states prohibit; 28 states permit; other states are silent |
| Fixing a mail ballot problem (cure) | Ballot cure process offered statewide | 33 states and D.C. have a ballot cure process |
| Mail ballot processing starts | Upon receipt | 43 states and D.C. begin processing before Election Day |
| Electronic ballot return | Permitted for UOCAVA voters, voters with disabilities and voters in extenuating circumstances | 32 states and D.C. allow for military and overseas voters; 13 states and D.C. allow for voters with disabilities |
Rules are those listed by the Election Assistance Commission and the National Conference of State Legislatures in January 2026; the right-hand column compares with all states. Laws can change, so check your state election office before you vote.
After the vote and primariesrecounts, audits and primary type
| Topic | Colorado | All states |
|---|---|---|
| Automatic recount | Uses automatic recount threshold | 25 states and D.C. have automatic recount thresholds |
| Post-election audit | Uses post-election audits | 49 states and D.C. require post-election audits |
| Primary elections | Open to unaffiliated voters | Primaries range from fully open to fully closed |
How people voted in 2024: Coloradoballots by mode, mail voting and election administration
- In-person early 3.4% (109,209)
- By mail 91.3% (2,957,550)
- In person on Election Day 4.4% (141,556)
- Other 1.0% (32,439)
| Mail voting in 2024 | Colorado |
|---|---|
| Mail ballots sent to voters | 4,090,266 |
| Share of sent mail ballots returned | 73.4% |
| Share of returned mail ballots counted | 98.6% |
| Mail ballots that went through ballot curing | 2.2% |
| Drop boxes | 10.6% of mail ballots returned at drop boxes |
| Running the 2024 election | Colorado |
|---|---|
| Active registered voters (Nov. 5, 2024) | 4,074,612 |
| Registration transactions in the two years to the 2024 close | 3,832,931 |
| Voters removed from the rolls in that period | 389,334 |
| Confirmation notices sent | 523,868 |
| Voting locations | 366 |
| Poll workers | 7,587 |
| Election jurisdictions reporting | 64 |
| How registrations arrived | Share |
|---|---|
| In Person | 1.7% |
| Online | 18.6% |
| Mail, Email, Fax | 7.1% |
| Other | 15.2% |
| Automatic Registration | 57.5% |
Audits and checks reported: Access audit: no; Ballot reconciliation audit: no; Compliance audit: no; Eligibility audit: no; Legal audit: no; Logic/accuracy testing: yes; Post-election tabulation audit: yes; Risk-limiting audit: yes; Other audit(s): no.
Reported by the state to the U.S. Election Assistance Commission (2024 Election Administration and Voting Survey). Reported Percentages may not sum to 100 because of missing answers. Read the EAC brief for Colorado.
Who runs elections in Coloradoofficial, local offices and website
- Chief election official: Secretary of State
- Who runs elections locally: County Clerk
- Election jurisdictions: 64
- State election website: www.coloradosos.gov/pubs/elections
Source: EAC and NCSL State Election Profile for Colorado, January 2026. Neither organization advocates for or against any election policy.