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CO · sourced voting rules

How elections work
in Colorado

Rules that shape registration and voting, the officials responsible for administering them, and the gaps that still require an election-specific source.

Official election website ↗Who runs the election →

Make your voting plan

Colorado
Voter registration guideOfficial registration options ↗Open my election officeOfficial voter services ↗Deadlines and rulesCheck your state’s sources →

Dates for November 3

Download calendar ↓

Partial coverage: only the dated entries below have been checked. Confirm other deadlines and exceptions with your election office.

Colorado · Sourced election dates
ActionDateDetails and source
Register online
8 days left		Register online by this date to receive a ballot by mail; later in-person voting options remain.
Official source ↗
Register by mail
8 days left		Register by mail or agency by this date to receive a mailed ballot.
Official source ↗
Early voting begins
1 day left		Required voter service centers begin opening; check exceptions and county hours.
Official source ↗
Return ballot
16 days left		County clerk must receive domestic ballots by 7 p.m.; military/overseas rules differ.
Official source ↗

Checked 2026-10-16. Confirm local details and exceptions with your election office.

Background registration and voting policy
State policy snapshot · not legal advice

Registration, primary, and voting methods

These values preserve the wording in the March 2026 EAC/NCSL profile. Asterisks and qualifications are meaningful; confirm the current election notice before acting.

Primary systemOpen to unaffiliated voters
Registration deadline policy8 days before Election Day to receive mail ballot
Same-day registrationPermitted
Early in-person votingBegins 15 days before Election Day for general elections
No-excuse absentee votingPermitted; ballots are mailed to all active registered voters
Mail-ballot return policy7 p.m. on Election Day
RANKED-CHOICE VOTING

Not established by this source

The current EAC/NCSL comparison profile does not provide a complete statewide RCV rule field. Election.org does not infer one.

WRITE-IN RULES

Not established by this source

Eligibility, filing, and counting rules can be election-specific. Use the official state election website.

RUNOFF OR WIN THRESHOLD

Read the election notice

The primary-system field above is published. A complete contest-by-contest threshold rule is not.

OFFICIAL BALLOT ORDER

Address and election required

A statewide rules profile cannot establish a voter's complete local specimen ballot.

Source: U.S. Election Assistance Commission / NCSL State Election Profile for Colorado ↗ · published March 2026 · verified 2026-08-24. Confirm current election details ↗