Illinois Farmland Reassessment: When an Appeal Is Worth It
How Illinois Farmland Is Assessed — It Is Not What You Think
Illinois farmland is not assessed on its sale price. This is the foundational fact that most farmland owners do not know, and not knowing it leads to two opposite errors: landowners who are alarmed by an assessment that has risen sharply because land values have risen sharply, and landowners who file appeals based on the argument that their ground is worth less than its assessment reflects — when the assessment has nothing to do with market value.
Illinois farmland is assessed on its earning capacity — specifically on the Soil Productivity Index rating of each soil type on the parcel, converted to an Equalized Assessed Value using a state-mandated formula that incorporates average commodity prices and production costs over a multi-year period. The result is a Farmland Productivity Rating that reflects what the ground should earn in average conditions, not what it would bring at auction today. When the Illinois statewide certified farmland values are published each year by the Illinois Department of Revenue, they are the output of that income-approach formula, not a market value survey.
What this means in practice: a year in which central Illinois farmland sales prices rise from $12,000 to $14,000 per acre does not automatically produce a corresponding increase in certified farmland assessment values. The assessment values lag market values because they are based on a formula that averages commodity prices and production costs over time — not on what land is selling for in the current year. Conversely, a year in which commodity prices fall does not produce an immediate assessment reduction, because the formula averages past years into the current calculation. The assessment system is deliberately counter-cyclical in a way that makes it hard to use current market data to argue for or against a specific assessment.
The 30-Day Filing Window You Cannot Miss
Each Illinois township publishes its assessment rolls in a local newspaper once per year — typically in late summer or fall. The Board of Review complaint filing window opens with that publication and closes 30 calendar days after the publication date. A landowner who misses the 30-day window cannot appeal that year's assessment through the Board of Review. They must wait for the following year's publication and file then.
The publication date varies by township and by county. In Menard County and surrounding counties, the publications typically run in September and October. A landowner who subscribes to their county seat newspaper — or checks the county assessor's office website, which increasingly publishes the assessment notice dates — can track when the window opens. A landowner who does not track it and discovers they were assessed incorrectly in March, after the December filing deadline has passed, has lost the opportunity for that year.
The Board of Review complaint is a relatively clear filing — the state provides form PTAX-230 for farmland complaints — but it requires documentation of the specific error that justifies a reduction. Filing a complaint without documentation of a specific, provable error is not an effective use of the process.
The Two Cases Where a Farmland Assessment Appeal Is Worth Filing
The first case is misclassified acres. Illinois distinguishes between farmland assessed on the productivity formula, non-farm land assessed at its fair market value, and land in transition between those categories. A field that has been enrolled in CRP or converted to a non-agricultural use may be assessed at the farmland rate when it should be assessed at the non-farmland rate, or vice versa. More commonly, a parcel has woodland, waterway, or road acres that are correctly classified as non-farmland but are being assessed at a farmland productivity rate, or has tillable acres that are classified as a lower productivity tier than their actual soil type supports.
Check the assessment notice against the actual FSA farm records and the NRCS soil survey for the parcel. If the tillable acres on the assessment do not match the FSA farm records, or if the soil type assigned to specific fields does not match the NRCS Web Soil Survey PI for those fields, you have a documentable error worth appealing. This type of error is not uncommon on parcels that have been farmed under the same ownership for decades without anyone reviewing the underlying assessment data — the original classification may reflect conditions that no longer exist, or may have been entered incorrectly when the parcel was first assessed.
The second case is a wrong soil PI assignment. The productivity index assigned to each soil series in an Illinois county is set by the state and is applied to every parcel with that soil series in the county. If the soil type assigned to a specific field does not match what is actually there — because the original soil mapping was done at a scale that missed a significant area of lower-PI soil, or because the field has been tile-drained in a way that changed its effective productivity tier — the resulting assessment may be higher than the actual soil supports. A current NRCS soil survey overlay on the parcel, compared to the soil types on the assessment notice, is the documentation for this type of appeal.
When an Appeal Is Not Worth Filing
A rising farmland assessment in a year when land values have risen is not a basis for a Board of Review appeal, because the assessment is not based on market value. The argument that "land has gone up but farm income is tight, so my taxes should not have increased" does not align with how Illinois farmland assessment works. The certified values are set at the state level using the productivity formula — an individual Board of Review cannot override a state-certified value on the basis that the landowner believes the formula produces the wrong result for their situation.
Similarly, a comparison to a neighbor's lower assessment per acre is not sufficient grounds for a complaint unless you can show that the neighbor's lower assessment reflects a different soil productivity rating that should also apply to your ground. If the neighbor has a legitimately lower PI soil type, their lower assessment is correct for their ground and does not support an appeal for yours. If the neighbor has the same soil type and a lower assessment, that comparison may support a complaint — but it requires documentation of the soil type similarity, not just the per-acre comparison.
The Practical Step for This Fall
Pull your county's current assessment publication date from the assessor's office or the county seat newspaper. Mark the 30-day filing deadline on your calendar. Pull your current assessment notice and compare the soil type assignments and tillable acreage against your FSA farm records and the NRCS Web Soil Survey for the parcel. If you see a mismatch in classified acres or soil PI assignment, contact the township assessor before filing a Board of Review complaint — many classification errors can be corrected at the assessor level without a formal hearing, which is faster and simpler for both the landowner and the assessment system. A formal Board of Review complaint is warranted when the assessor cannot or will not correct a documented error at their level.
Jared Williams is the Managing Broker and owner of Archer Realty & Auction LLC. He serves on the Menard County Board of Review and specializes in agricultural land transactions and landlord advisory services across central Illinois. Start the conversation at archerrealty.net.
