2026 Appeal Deadline Guides / Missouri
St. Charles County, MO Property Tax Appeal Deadline 2026
2026 appeals to the St. Charles County Board of Equalization are due by the deadline in RSMo §137.385 — the second or third Monday in July, depending on the county (July 13 or July 20, 2026). Confirm St. Charles County's exact date on your notice or the board's website before relying on either date.
- 2026 filing window
- By the second or third Monday in July (July 13 or 20, 2026) — county-specific
- Where to file
- St. Charles County Board of Equalization
- Form
- County Board of Equalization appeal form (from the county)
- Filing fee
- $0 — no filing fee
- How to file
- Online portal, mail, or in person
- Governing law
- RSMo §137.385; §138.060
Missouri routes property appeals through the county first: you must appeal to the St. Charles County Board of Equalization before you can go to the State Tax Commission — skipping the county board forfeits the state-level appeal. The petition is filed in writing on the county's form by the deadline in RSMo §137.385: the second or third Monday in July, depending on the county (July 13 or July 20, 2026).
The July window around St. Charles, O'Fallon and St. Peters is short and closes fast. If it has already passed for 2026, one thing still matters this year: paying your taxes under written protest before December 31 preserves a refund claim while you position for next year's appeal.
How to appeal in St. Charles County — step by step
- 1
Confirm your county's July deadline
RSMo §137.385 sets it at the second or third Monday in July depending on the county — July 13 or July 20 in 2026. The date on your notice or the board's website controls.
- 2
Gather market evidence
Recent sales of comparable homes are the strongest support for a lower value — similar size, age, and neighborhood, as close to your home as possible.
- 3
File in writing on the county's form
Submit the Board of Equalization appeal form to the St. Charles County Board of Equalization before the deadline. Online portal, mail, or in person.
- 4
Present to the board
Walk through your comparable sales and any errors in the county's record of your home (square footage, condition, features).
- 5
Protect a refund if the window already closed
Pay your taxes under written protest before December 31 to preserve a refund claim — and remember the county board is a mandatory first step: the State Tax Commission can't hear an appeal that skipped it.
Is your St. Charles County home over-assessed?
Free 5-minute check against county data — see your estimated savings before you decide anything. If a records-based appeal packet is available for your area, it's $39 with a 7-day unconditional refund: any reason, any time before you download it.
Check my property — freeFrequently asked questions
When is the deadline to appeal property taxes in St. Charles County in 2026?
2026 appeals to the St. Charles County Board of Equalization are due by the deadline in RSMo §137.385 — the second or third Monday in July, depending on the county (July 13 or July 20, 2026). Confirm St. Charles County's exact date on your notice or the board's website before relying on either date.
What does it cost to file?
$0 — no filing fee. The appeal itself is an administrative filing with the county board.
Can I go straight to the State Tax Commission?
No — appealing to your County Board of Equalization first is mandatory. Skipping it forfeits the State Tax Commission appeal.
What if I miss the July deadline?
Pay your taxes under written protest before December 31 to preserve a refund claim, and calendar next June — Missouri's board window opens and closes quickly each July.