St. Charles Property Tax: Rates, Exemptions & BOE (2026)

Direct answer: For 2026, St. Charles County Board of Equalization (BOE) assessment appeals had to be received by 5 p.m. on Monday, July 13, 2026—the second Monday in July. File with the St. Charles County Registrar, preferably through the county’s online BOE appeal form, or by mail/in person at 201 N. Second St., Suite/Room 541, St. Charles, MO 63301; because that 2026 deadline has passed, the next regular BOE deadline is expected to be Monday, July 12, 2027, unless the county publishes a different 2027 notice. (sccmo.org)

How assessments work in St. Charles County

St. Charles County’s Assessor, Travis Welge, sets fair market value as of Jan. 1 for property-tax purposes; the Assessor does not set the tax rate. Taxing districts—schools, cities, fire districts, ambulance, library, community college and others—set levies, and the Collector bills and collects. (sccmo.org)

The county’s last general real-estate reassessment was for Jan. 1, 2025 values. Missouri requires real estate to be re-evaluated every odd-numbered year, so 2026 is not a countywide reassessment year for most homes; 2025 values generally carry forward unless there is new construction, a correction, a subdivision/record change, or another legally recognized change. New construction is added annually, and in St. Charles County newly occupied residential construction is added the first day of the month after occupancy. (sccmo.org)

The 2025 reassessment was significant but not as extreme as 2023. The county reported that total residential values increased 8.4% since 2023, compared with a 24% increase in the prior reassessment cycle. The Assessor said values are based on factors such as location, square footage, condition, amenities, bedrooms, baths, fireplaces, basement, garage and comparable nearby sales. (sccmo.org)

For a homeowner, the tax formula is: market value × 19% residential assessment ratio ÷ 100 × your combined tax rate. Residential property is assessed at 19% of market value; agricultural is 12%; commercial/all other is 32%. (sccmo.org)

Whether you should appeal

Appeal if your county value is higher than what the home would likely have sold for on the valuation date, or if the county’s facts are wrong. St. Charles County specifically tells owners to check comparable sales, similar assessments and property-record details. Useful issues include an overstated finished basement, wrong square footage, missing condition problems, outdated kitchens/baths, foundation problems, roof damage, water intrusion, or a sale price/appraisal near the assessment date. (sccmo.org)

Local data suggests informal review is worth trying when you have evidence. During the 2025 reassessment, the county reported about 2,000 real-estate reassessment appeals: about 1,500 informal hearings and 500 scheduled formal BOE hearings. The county also reported that about 75% of owners who attended informal hearings received a reduction, according to the Assistant Assessor of Real Estate. That is not a guaranteed BOE success rate, and no median dollar reduction was published in the official sources I found. (sccmo.org)

A realistic savings example: suppose an O’Fallon homeowner in Fort Zumwalt R-II with fire district 13 has a 2025 combined rate of 5.7560 per $100 assessed value, plus the O’Fallon city rate of 0.4216, for a working combined rate of 6.1776. If the county value is $450,000 and you prove $420,000, the market-value reduction is $30,000. The assessed-value reduction is $30,000 × 19% = $5,700. Estimated annual tax savings: $5,700 ÷ 100 × 6.1776 = about $352. Your exact rate depends on your school, fire, city and special districts. (sccmo.org)

Step-by-step how to file

1. Start with the Assessor’s informal process. In reassessment years, notices normally arrive in late April and informal hearings run from late April through early June. In a non-reassessment year, contact Real Estate at 636-949-7428. For the 2025 reassessment, owners had 10 days from the mailed notice date to schedule an informal hearing; future notice instructions may differ, so follow the mailed notice. (sccmo.org)

2. If you still disagree, file the BOE appeal. The official form name is “Property Assessment Appeal Form — St. Charles County Board of Equalization (BOE).” A separate form is required for each account or locator number, and the form asks for the owner’s opinion of fair market value and the Assessor’s value being appealed. If an agent represents you, use the county’s Agent Authorization Form. (sccmo.org)

3. Use the accepted filing routes. The county links to an online BOE form from the BOE and Registrar pages. The paper form says it must be postmarked or delivered in person to St. Charles County BOE, 201 North Second Street, Room 541, St. Charles, MO 63301, 636-949-7560. The Registrar page lists the office at 201 N. Second St., Suite 541, Monday–Friday, 8 a.m.–5 p.m. The county pages show an “Email” contact link, but the official appeal instructions I found do not say email is an accepted filing method for BOE appeals; use the portal, mail, or in-person delivery unless the Registrar confirms otherwise. (sccmo.org)

4. Attach evidence with the appeal. St. Charles County says evidence should be submitted with the appeal form. Good homeowner evidence includes current photos, a recent appraisal, a Realtor opinion letter, comparable sales, closing statement, sales contract, construction costs, capital-improvement costs, or costs to cure deferred maintenance. Missing support can result in a no-change decision. No BOE filing fee is published on the county BOE page or the form excerpts I found. (sccmo.org)

What happens after

The proper local appeal authority is the St. Charles County Board of Equalization. It is a three-member citizen board appointed by the County Executive; members must have some real-estate-related experience such as broker, appraiser, builder, developer, lending officer or investor experience. (sccmo.org)

For 2026, BOE hearings are held by phone or in person at the Missouri Job Center of St. Charles County, 3757 Harry S Truman Blvd., St. Charles, MO 63301. After your appeal is accepted, the county sets an appointment in July or August. The board hears from both the Assessor’s Office and the property owner on the disputed assessment. (sccmo.org)

County code says the BOE meets between the first Monday in June and the fourth Saturday in August during a general reassessment year, as often as necessary, and those reassessment hearings must be concluded by the fourth Saturday in August. The BOE can reduce property returned above true value, keep records, and file the original record with the Registrar within 30 days of a meeting. (ecode360.com)

If you lose or are only partly satisfied, the next level is the Missouri State Tax Commission (STC). For real estate, the STC deadline is Sept. 30 of the assessment year or 30 days after the BOE decision, whichever is later. The STC prefers online filing of the Complaint for Review of Assessment; it also accepts the form by email to Legal@stc.mo.gov or by mail to State Tax Commission of Missouri, P.O. Box 146, Jefferson City, MO 65102-0146. You generally must upload or include the BOE decision letter. (stc.mo.gov)

Local tips

Do not argue “my taxes are too high” by itself. In St. Charles County, the stronger argument is that the market value is wrong. The county’s own Assistant Assessor said the best evidence is often photos showing condition problems or dated kitchens and baths. (sccmo.org)

Check tax relief separately from appeals. St. Charles County’s Seniors Real Estate Property Tax Relief Program applied in 2026 to primary residences of county residents who were at least 62 and living in the home as of Jan. 1, 2026. The 2026 period ended July 6, 2026 after an extension; approved owners should monitor the county status lookup. The credit applies across St. Charles County taxing jurisdictions, but not to bonded indebtedness or the State Blind Pension Fund, and mobile homes taxed as personal property do not qualify. (sccmo.org)

Also check the Missouri Property Tax Credit (MO-PTC) if you are 65 or older or 100% disabled and meet income limits, and the Disabled POW real-property exemption if applicable. St. Charles County’s assessment notice specifically points homeowners to those programs; Missouri does not offer a general owner-occupied homestead exemption for every homeowner through the county assessment appeal process. (sccmo.org)

Finally, remember the tax bill schedule: St. Charles County tax bills are mailed by Dec. 1 and due Dec. 31. If an appeal changes your value after billing, watch for a revised statement, but payment is still due Dec. 31 unless the Collector or state law says otherwise. (sccmo.org)

St. Charles County Property Tax Rate

No single countywide residential millage applies. The most recent official posted St. Charles County chart is the 2025 tax-rate chart, stated per $100 of assessed valuation: common tax is 0.8222, and the listed school/fire/college combination totals range from 4.9560 to 6.7303 before any applicable city taxes; city rates are listed separately.

Source: https://sccmo.org/Archive.aspx?ADID=5252

When Are Property Taxes Due in St. Charles County?

Property tax bills are mailed by Dec. 1, and tax payments are due Dec. 31; revised statements are still due Dec. 31. The Collector accepts partial payments before Dec. 31 and advance payments for future bills; partial payment reduces late-payment interest/penalties but does not replace the Dec. 31 due date for the remaining balance.

This is not the same as the assessment appeal deadline above. The appeal deadline is your window to contest your assessed value; the payment due date is when the resulting tax bill must be paid. Missing one does not affect the other, but missing either has real consequences — one forfeits your right to appeal for the year, the other can trigger penalties and interest.

Source: https://sccmo.org/2154/About-Assessments-and-Taxes

Property Tax Exemptions in St. Charles County

• St. Charles County Seniors Real Estate Property Tax Relief Program — St. Charles County residents whose primary residence is the property for which they apply, who were at least 62 years old and living at the property as of Jan. 1, 2026; property taxed as personal property, including mobile homes, does not qualify.. A credit on the real-estate tax bill that can reduce future increases after the taxpayer’s base-year bill; it applies to taxing jurisdictions within St. Charles County but not to bonded indebtedness or the State Blind Pension Fund. Yes, apply or renew every year. Apply by For tax year 2026, the application period was March 1-July 6, 2026.. (Source: https://sccmo.org/2343/Seniors-Real-Estate-Property-Tax-Relief-)
• Missouri Property Tax Credit Claim / Circuit Breaker — Certain senior citizens and 100% disabled individuals for a portion of real estate taxes or rent paid for the year; homeowners must have owned and occupied the home.. Maximum credit is $1,100 for owners who owned and occupied their home, and $750 for renters; actual credit depends on real-estate taxes or rent paid and total household income. Yes, claim through Missouri Department of Revenue; filing options include MO-PTC if claiming only the property tax credit, or MO-1040 with MO-PTS if filing an individual income tax return. (Source: https://dor.mo.gov/taxation/individual/tax-types/property-tax-credit/)
• Disabled Former Prisoner of War Homestead Property Tax Exemption — Missouri citizen who is a former prisoner of war, is a veteran with a total service-connected disability, and owns and occupies the homestead as a primary residence.. Exempts the real property used as the qualifying homestead from taxation. Yes, provide the county assessor proof of primary-residence occupancy, proof of service-connected total disability, and POW documentation such as DD-214 or a qualifying letter. (Source: https://stc.mo.gov/faq/are-veterans-or-former-pows-exempt-from-property-tax-2/)
• Missouri Public Safety Officer Surviving Spouse Tax Credit — Unremarried surviving spouse of a public safety officer killed in the line of duty who owns a Missouri homestead and pays property taxes on the dwelling and surrounding land; the homestead may not be occupied by more than two families.. Refundable Missouri income tax credit equal to the amount of property taxes paid on the homestead. Yes, complete and attach Forms MO-SSC and MO-TC to the Missouri individual income tax return. Apply by No specific due date; returns filed on extension may claim the credit.. (Source: https://dor.mo.gov/tax-credits/ssc.html)

How to Look Up Your Property Record in St. Charles County

You can look up your property's official record at https://lookups.sccmo.org/assessor. The official Assessor property database provides searchable assessment records; the county notes assessor information is for assessment purposes and should not be used to verify or transfer ownership or as a legal survey.