Missouri
Fee-based candidate filing, notary-heavy initiative petitioning
Missouri is one of the easiest states in the country to get on a primary ballot — established-party candidates pay a fee as low as $50 and gather no signatures at all — and one of the more procedurally demanding states to run an initiative. Every petition page must be notarized, confined to one county, and circulated by someone pre-registered with the Secretary of State. The state is also in active flux: Amendment 4 on the August 2026 ballot would rewrite how citizen amendments pass.
Signature Requirements
| Office / Measure | Requirement |
|---|---|
| Established-party primary candidate | No signatures. Filing fee only: $200 statewide/U.S. Senate, $100 U.S. House and State Senate, $50 State House |
| Fee-waiver petition (in lieu of fee) | 0.5% of the total vote cast for that statewide office, or 1% of the vote cast in the district or subdivision |
| Independent candidate, statewide | 10,000 signatures of registered voters |
| Independent candidate, district office | 2% of the vote cast in that district at the last election, or 10,000, whichever is fewer |
| New party formation, statewide | 10,000 registered voters |
| Initiated constitutional amendment | 8% of the gubernatorial vote in each of 6 of 8 congressional districts — 170,215 minimum for the current cycle |
| Initiated statute or veto referendum | 5% in each of 6 of 8 congressional districts — 106,384 minimum for the current cycle |
| Per-district initiative range | Roughly 24,954–34,512 per district for amendments; 15,596–21,570 for statutes |
Filing structure and the tax affidavit
Established-party candidates file in person during a fixed window that opens at 8 a.m. on the last Tuesday in February and closes at 5 p.m. on the last Tuesday in March. Filing requires a declaration of candidacy, proof of identity, the fee receipt, and — a step outsiders routinely miss — a tax clearance affidavit filed with the Department of Revenue affirming no delinquent state taxes. In-person filing is mandatory except for candidates with a physical disability or on active military duty.
Independent and new-party window
Independent and new-party candidates operate on a completely different calendar: filing opens at 8 a.m. the day after the preceding general election and closes at 5 p.m. on the 15th Monday before the general election. That is a two-year runway that ends in late July of the election year. Independent candidates pay no filing fee; the petition is the price of admission.
Who may circulate an initiative
Circulators must be at least 18, must register with the Secretary of State before collecting, and may not have a forgery-related conviction. Registration is complete when a signed circulator's affidavit is delivered to the Secretary of State — and signatures gathered by an unregistered circulator after 5 p.m. on the filing deadline are not counted. Missouri does not impose a residency requirement on initiative circulators, and pay-per-signature is permitted.
Notarization is per page, not per campaign
Every petition page carries its own circulator affidavit that must be sworn before a Missouri-commissioned notary, who must verify the circulator's identity, witness the oath, and affix a seal. Each page may contain signatures from only one county, must show the county in the upper right corner, must have the official ballot title affixed, and must have the full measure text attached. False swearing is a class A misdemeanor carrying up to a year in jail or a $10,000 fine.
Verification bands and withdrawal
Local election authorities check signatures against registration records. The Secretary of State may order a full count or a 5% random sample; if the sample projects between 90% and 110% of the requirement, a complete verification is triggered. Missouri has no post-deadline cure period. Voters may withdraw their own signatures by filing a sworn statement before the petition is submitted.
Ballot Measures in Missouri
Missouri permits initiated constitutional amendments, initiated statutes, and veto referendums. Sponsors submit a sample petition to the Secretary of State, who has roughly 15 days to approve the form, then drafts a summary of 100 words or less while the State Auditor prepares a fiscal note summary of 50 words or less; the Attorney General approves both before the official ballot title is certified. Circulation may begin only after title certification and may run up to about 18 months, with all pages due in a single submission at 5 p.m. six months before the general election. Constitutional amendments require 8% of the last gubernatorial vote in each of six of the eight congressional districts; statutes and referendums require 5% on the same district-based test. Local election authorities verify within two to four weeks and the Secretary of State issues a certificate of sufficiency by the 13th Tuesday before the election. Ballot title and fiscal note challenges are routine, frequently litigated, and often consume months of the available circulation window.
What Trips Campaigns Up in Missouri
We've Worked This Ground
Missouri Ballot Access FAQ
Do Missouri primary candidates need signatures?
No. Candidates of established parties get on the primary ballot by paying a filing fee — $200 statewide, $100 for U.S. House and State Senate, $50 for State House. A petition is only needed if the candidate wants the fee waived, or is running as an independent or new-party candidate.
Does every Missouri petition page need a notary?
Yes for initiative and referendum petitions, and for candidate nomination petitions under § 115.325. The circulator signs an affidavit on each page sworn before a Missouri-commissioned notary. Pages with defective notarization are discarded entirely.
How does Missouri verify signatures?
Local election authorities compare signatures to registration records. The Secretary of State chooses between a full count and a 5% random sample; a sample landing between 90% and 110% of the requirement forces a full verification of every signature.
Can out-of-state circulators work in Missouri?
Yes. Missouri does not require initiative circulators to be state residents, but they must be 18 or older, must register with the Secretary of State before gathering, and must swear each page before a Missouri notary.
Running a Campaign in This State?
Signature requirements are the easy part. Hitting them on deadline is the job.