St. Charles County, MO Sign Regulations: Window Signs (2026)
Key Facts
- Max sign size
- 32 square feet
- Uses allowed
- 2 per calendar year
- Max duration
- 15 days per use
- Removal deadline
- Close of business, sale's last day
- Permitting agency
- Division of Planning and Zoning
- Penalty
- Up to $500/day or 6 months jail
- Applies to
- Commercial and Industrial districts only
Summary
St. Charles County caps on-premise window, sidewalk and business sale signs and banners at 32 square feet in Commercial and Industrial Districts, and limits businesses to two temporary runs a year, no more than 15 days each. A sign permit from the Division of Planning and Zoning is required first, and the sign must come down the same business day the sale ends.
h. Temporary signs are permitted. (The sign can either be an on-premise ground sign or attached to a structure.) (1) On-premise window, sidewalk, and business sale signs or banners not exceeding thirty-two (32) square feet. Maximum usage—two (2) per calendar year for no more than fifteen (15) days per time. Such signs or banners must be removed after the close of the business day in which the sales event ended.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4863880; v61 updated 2026-05-11; through 05-11-2026).
Full Breakdown
St. Charles County Code § 405.475(A)(2)(h) governs temporary signage in the Commercial ("CO", "C1", "C2") and Industrial ("I1", "I2") Districts of unincorporated St. Charles County. Subsection (h)(1) allows on-premise window, sidewalk, and business sale signs or banners not exceeding thirty-two (32) square feet, but caps use at two events per calendar year, no more than fifteen days each, and requires removal after the close of business on the day the sale ends. A companion provision, (h)(2), extends the same two-per-year, fifteen-day cap to cold-air inflatable advertising aids up to thirty-two feet tall, which need Division of Planning and Zoning sign-off and cannot be installed on a roof.
Because these signs sit in the "Signs Requiring Permits" article rather than the exempt list in § 405.480, a business must still obtain a sign permit under § 405.470 before hanging a window or sale banner. Applications route through the Division of Building and Code Enforcement, must include a scaled site plan showing the sign's dimensions and placement, and incomplete applications are not accepted. An application fee set under Chapter 425 accompanies every submission, and an unused permit lapses after 180 days (one 60-day written extension is available). A business already cited for an uncorrected sign violation cannot get another sign permit until the violation is fixed.
Disputes over a permit denial go to the Board of Zoning Adjustment; a BZA decision can then be appealed to the County Council within fourteen working days, or directly to Circuit Court under Missouri's zoning appeal statutes (§ 405.639).
Violations & Fines
Exceeding the thirty-two-square-foot limit, running a window or sale banner beyond fifteen days, using more than two temporary sign permits in a calendar year, or leaving the banner up past the close of business on the sale's last day is a Chapter 405 zoning violation. The Director of the Division of Planning and Zoning can order the sign removed; ignoring that order is a misdemeanor under § 405.645, punishable by a fine of up to $500 per day, up to six months in the County Jail, or both, with each day of continued violation a separate offense.
Frequently Asked Questions
Do I need a permit for a temporary window sign in unincorporated St. Charles County?
How many times a year can I put up a sale banner?
Does this rule apply county-wide?
What happens if I leave a sale banner up too long?
Sources & Official References
Other rules in St. Charles County
Compare St. Charles County to another location·View the Missouri sign regulations overview
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