How do I register to vote or check my registration?

Local Election Authority (county level - each Missouri county's Election Authority or County Clerk; City of St. Louis Election Board) / Missouri Secretary of State (state level)

Step by Step

How to do it

Confirm eligibility: Must be a U.S. citizen, Missouri resident, at least 17.5 years old to register (must be 18 to vote in most elections; 17.5 to vote in primary if 18 by general election), not currently confined under a sentence of imprisonment, not adjudicated incapacitated, and not convicted of a felony or misdemeanor connected with voting (unless pardoned)
Choose your registration method:
ONLINE: sos.mo.gov/elections/voterregistration - requires Missouri driver's license or state ID number; must be received by deadline
BY MAIL: Download Missouri voter registration form from sos.mo.gov; complete, sign, and mail to your Local Election Authority - must be received by 5:00 PM on the second Wednesday before Election Day (about 28 days)
IN PERSON: Local Election Authority (County Clerk or designated Election Board office); Missouri DOR Driver License offices (when conducting license transactions); many government assistance offices - in-person deadline: received by 5:00 PM the day before Election Day
Submit registration by the applicable deadline
Receive voter registration card confirming enrollment

Details

What you need to know

Required Docs

Missouri driver's license or state ID number (for online registration)
OR last 4 digits of Social Security number
Date of birth and current Missouri address

Fee

Free MAIL REGISTRATION DEADLINE: Received by 5:00 PM on the second Wednesday before Election Day (approximately 28 days before) ONLINE REGISTRATION DEADLINE: Received by same as mail deadline IN-PERSON DEADLINE: By 5:00 PM the day before Election Day (more time than mail/online) NO SAME-DAY REGISTRATION: Missouri does NOT offer same-day voter registration CHECK YOUR REGISTRATION: sos.mo.gov/elections/voterregistration ABSENTEE VOTING: Missouri has limited excused absentee voting: - Will be absent from county on Election Day - Incapacity or illness - Religious belief (observing religious holiday) - Employed in election on Election Day - Age 65+ (may vote absentee without excuse - new as of recent law) - Active military or overseas voter IN-PERSON ABSENTEE: Available from second Wednesday before election through day before election at election authority office; no excuse required in some counties for in-person absentee during early period - check your local election authority BY MAIL: Requires qualifying excuse; application deadline typically at least 7 days before election ONLINE OPTION: Yes - sos.mo.gov/elections/voterregistration WHERE TO GO: Local Election Authority (County Clerk or Election Board); Missouri DOR Driver License offices; many government agencies

Online Option

Yes - sos.mo.gov/elections/voterregistration

Where to Go

Local Election Authority (County Clerk or Election Board); Missouri DOR Driver License offices; many government agencies

County-specific variations apply

Voter registration administered by Local Election Authorities (LEAs) - County Clerks in most counties; dedicated Election Boards in larger jurisdictions (Jackson County/Kansas City, St. Louis County, St. Louis City, Greene County/Springfield, Boone County/Columbia). Moving between Missouri counties: re-register with new county LEA. City of St. Louis has its own Election Board separate from St. Louis County. Contact your specific LEA for local absentee voting procedures.

Missouri Notes

Important state-specific details

NO same-day voter registration in Missouri.
In-person registration deadline (day before election by 5 PM) is later than mail/online deadlines - useful if approaching an election.
ABSENTEE VOTING: Missouri has restrictive absentee requirements with excuses required for most mail voting; seniors 65+ now qualify without excuse; early in-person absentee at election authority office is the most accessible early option.
PHOTO ID REQUIRED: Missouri requires photo ID to vote; acceptable: Missouri driver's license/state ID, Missouri non-driver ID, military ID (with/without expiration), U.S. passport (with/without expiration), ID from state or federal agency/university/military. Without qualifying photo ID: may cast a provisional ballot if voter signs a sworn statement.
FELONY CONVICTION: Voting rights suspended while incarcerated OR on parole OR on probation for a felony; rights automatically restored when "finally discharged" from probation or parole (must re-register); election offenses (misdemeanor or felony) permanently disqualify unless pardoned.
Pre-registration available at 17.5 years old; can vote in primary if will be 18 by general election.
Polls open 6:00 AM - 7:00 PM; anyone in line at closing must vote.

Official Source

State office contact

State Office

Missouri Secretary of State, Elections - sos.mo.gov/elections | (800) 669-8683; Local Election Authority (varies by county/city)