How Missouri Property Assessments Work
Missouri assesses all real property as of January 1 each year. Residential property is assessed at 19 percent of estimated true (market) value — meaning if your assessor believes your home is worth $400,000, your assessed value will be approximately $76,000. Your annual tax bill is then calculated by multiplying the assessed value by your combined local levy rate.
Full reassessment of all real property occurs in odd-numbered years (2025, 2027, etc.). In even years, assessments may be adjusted for new construction, additions, or significant changes, but most residential properties hold their odd-year value. This means the 2025 reassessment cycle — with notices mailed in mid-2025 — established values that remain in effect through 2026 for most homeowners.
The assessed value on your notice is the assessor's estimate of what your property would sell for on the open market on January 1. If you disagree with that estimate and have evidence to support a lower market value, you have a statutory right to appeal through several levels of review.
The Three-Step Appeal Sequence
Missouri property tax appeals follow a structured sequence. Missing a deadline at any step generally closes that path for the current year.
Step 1 — Informal Hearing with the County Assessor
The first step is an informal meeting or written review with the county assessor's office. You present your evidence; the assessor's staff reviews the assessment. Many adjustments happen at this stage without going further. This is the lowest-cost, lowest-complexity step — and the deadline is typically the earliest.
In both Clay and Platte counties, the informal deadline is generally within 30 days of the date your assessment notice was mailed, often in late June of the reassessment year. Confirm the exact date with your county assessor — this deadline changes and late submissions are not typically accepted.
Step 2 — Board of Equalization (BOE)
If the informal hearing does not resolve the dispute, the next step is a formal hearing before the county Board of Equalization. The BOE is a separate body from the assessor's office and holds hearings typically beginning in July of the reassessment year. Both Clay and Platte counties have BOE application windows that open after assessment notices are mailed.
At a BOE hearing, you present your evidence (comparable sales, an appraisal, or other market value documentation) and the assessor's office may respond. The BOE issues a written decision. If you disagree with the BOE decision, you may escalate to the Missouri State Tax Commission.
Step 3 — Missouri State Tax Commission (STC)
The State Tax Commission is the statewide appellate body for property tax disputes. STC appeals are more formal, involve filing fees, and have their own procedural requirements. Most homeowners with straightforward residential value disputes resolve their appeals at the informal or BOE stage. The STC is typically used for complex cases, large commercial disputes, or when the BOE result is clearly inconsistent with evidence. Information on filing an STC appeal is at stc.mo.gov.
County-Specific Information and Official Sources
| County | Assessor / Real Property Portal | Senior Relief Program |
|---|---|---|
| Clay County | claycountymo.gov/222/Real-Estate | Senior Tax Relief Program |
| Platte County | co.platte.mo.us/real-property | Platte County Tax Credit |
| Missouri STC | stc.mo.gov — How to File an Appeal of Your Assessment | |
What Evidence Actually Works
The most common mistake homeowners make in a tax appeal is arguing that their taxes are too high in dollar terms rather than providing evidence that the assessed value overstates market value. The assessor does not set tax rates — that is done by the taxing jurisdictions (school district, city, county, etc.). The only thing a property assessment appeal can change is the assessed value.
Strong evidence:
- Recent comparable sales — homes that sold in the prior 12 months, similar in square footage, age, condition, and location. Ideally within the same subdivision or neighborhood. Pull these from the county assessor's online portal or request them directly.
- A licensed appraisal dated as of or near January 1 of the assessment year, estimating a value below the assessed value. This is the strongest evidence but carries an upfront cost (typically $400–$600 for a residential appraisal in the Northland).
- Your own recent purchase price if you purchased the property near January 1 of the assessment year at a price lower than the assessed value — an arm's-length sale is strong evidence of market value.
Weak or ineffective evidence:
- Automated value estimates (Zestimate, AVM) — these are not accepted as evidence of market value by Missouri assessors or the BOE.
- Comparisons to your neighbor's assessed value — neighbors may have appealed, have different conditions, or be assessed on different dates.
- Statements that you could not sell for the assessed value without any sale evidence or appraisal.
- Objections to the tax rate or tax bill amount rather than the assessed value.
Senior Tax Relief Programs
Both Clay and Platte counties offer property tax relief programs specifically for seniors, typically with age (generally 62 or 65+) and income eligibility requirements. These programs operate separately from the standard assessment appeal process and have their own application windows, deadlines, and documentation requirements.
Do not assume the appeal deadline applies to senior relief applications. Senior relief applications often have different deadlines — sometimes earlier in the year — and must be filed directly with the county. Qualification criteria, income limits, and maximum benefit amounts are set by each county and may change annually.
- Clay County Senior Real Estate Tax Relief: claycountymo.gov/523/Senior-Real-Estate-Property-Tax-Relief
- Platte County Tax Credit Program: co.platte.mo.us/tax-credit
Missouri also offers a state-level Circuit Breaker program for qualifying seniors and disabled individuals through the Department of Revenue. See dor.mo.gov for current eligibility requirements.
What This Means if You Are Buying or Selling
If you are purchasing a Northland property, the current assessed value is public record and may not reflect the price you are paying — especially if the property has not been reassessed since a rising market. A higher purchase price than the current assessed value may result in a higher reassessment at the next cycle. This is not a reason to avoid purchasing but is useful context for budgeting future tax obligations.
If you are selling, buyers may ask about the property's tax history. The assessed value and tax bill are visible in the MLS and county records and are typically disclosed in the transaction. An unusual gap between assessed value and list price may prompt buyer questions.
Decision Checklist — Before You Appeal
- Obtain your assessment notice and note the exact date it was mailed — the informal appeal deadline runs from that date.
- Pull recent comparable sales from the county assessor's online portal and compare them to your assessed value.
- Determine whether comparable sales support a lower market value, or whether the assessed value is in the right range.
- Decide whether to handle the appeal yourself or hire a licensed appraiser to provide formal evidence.
- File the informal appeal before the county-specific deadline. Do not wait for the BOE application window — the informal step comes first.
- If you are 62 or older, separately check the senior relief program deadlines — they may differ from the assessment appeal deadline.
Frequently Asked Questions
How is residential property assessed in Missouri?
Missouri residential property is assessed at 19 percent of estimated true (market) value as of January 1 each year. Full reassessment occurs in odd-numbered years. The assessed value drives your tax bill — if you believe it exceeds what your property would actually sell for, you have the right to appeal.
What is the appeal deadline for Clay County property tax assessments?
Clay County assessment notices are typically mailed in late May or early June of odd reassessment years. The informal appeal deadline is generally 30 days from the notice date, and the Board of Equalization hearing period typically opens in July. Deadlines change each cycle — verify current dates directly with the Clay County Assessor at claycountymo.gov before taking any action.
What evidence do I need to win a property tax appeal?
A successful appeal requires evidence that the assessed value exceeds market value as of January 1. Bring recent sales of genuinely comparable properties — same general area, similar age, size, and condition. A licensed appraisal is the strongest evidence but is not required at the informal stage. Automated value estimates (Zillow, etc.) are not accepted as evidence.
What senior tax relief is available in Clay and Platte counties?
Both Clay and Platte counties offer senior property tax relief programs with income and age requirements. Application deadlines and qualification windows differ from the standard assessment appeal process. Clay County: claycountymo.gov. Platte County: co.platte.mo.us.