Peoria County property owners who believe an assessment is incorrect have a defined route for review, but timing matters. The County Board of Review accepts and acts on property-tax assessment complaints, while applications and tax bills involve other offices and processes.

Check the 2026 filing deadline first

Peoria County lists September 30, 2026 as the 2026 Board of Review filing deadline. A homeowner should verify the current deadline directly with the County before filing because deadlines and township schedules can change.

Identify the assessment you are questioning

Start with the parcel number, address, assessment notice, and the specific value or characteristic that appears incorrect. Keep copies of the notice and any prior appeal outcome.

Use evidence that addresses the property

Comparable sales, photographs, repair information, property characteristics, and other records may be useful when they relate to the assessment question. General neighborhood opinions rarely answer a parcel-specific issue.

Understand the Board of Review’s role

Peoria County describes the Board of Review as an appeal body that accepts, reviews, and acts on assessment complaints. It also reviews certain exemption applications before they go to the Illinois Department of Revenue. That is different from setting a tax rate or collecting a bill.

Keep records for future ownership decisions

Property Records of Illinois may provide available sales, tax, ownership, mortgage, lien, and property-history details in one report. Use the County’s official materials for an appeal and keep every submission and decision with the property file.