Informal Review and Formal Appeal Process

Time-Sensitive Information

All property owners will receive an appraisal notice in 2025 for the 2025–2026 valuation cycle.

If you disagree with your valuation or need corrections to your property’s characteristics, you must submit a Request for Informal Classification and Appraisal Review (Form AB-26) within 30 days of the date on your classification and appraisal notice. Approved valuation adjustments will apply to tax years 2025 and 2026.

If you miss the 30-day deadline, you may submit a request for informal review until June 1, 2026. Any valuation adjustments submitted after the deadline will apply to Tax Year 2026 only.

If you have questions about the classification or value shown on your property appraisal notice, you have options to request a review or file an appeal. This page explains the informal review process, formal appeal options, and important deadlines.

Steps to Request an Informal Review

We want to make sure you don't have any questions about your property.

You can use Property.MT.Gov to view details about your property and review its characteristics, such as:

  • square footage
  • number of bedrooms
  • number of bathrooms

You may contact your field office to talk to an appraiser. We will make every effort to address your concerns and resolve any possible misunderstandings.

If you have no additional concerns, your local county treasurer's office will use the values reported in your classification and appraisal notice to calculate your property tax bill.

Gather the Required Information

Before filling out your Request for Informal Classification and Appraisal Review (Form AB-26), be sure to have your classification and appraisal notice, showing your:

  • Assessment Code
  • Geocode
  • Current Assessed Value

Supporting Documents for Requesting a Valuation Change

If you are requesting a valuation change not related to physical characteristic changes, submit any of the following documents you have available:

  • Your own estimate of the subject property's market value as of January 1, 2024. This is the valuation date for the 2025–2026 valuation cycle.
  • The purchase price of the subject property within six months of the January 1, 2024, valuation date; copy of executed buy/sell agreement.
  • A fee appraisal within six months of the January 1, 2024, valuation date.
  • Comparable property sales or listings within six months of the January 1, 2024, valuation date.
  • Builder's cost breakdown worksheet for building remodels or construction.
  • Detailed information on income and expenses for income-producing commercial or industrial property.

Formal Appeals

You can choose to appeal the classification or assessment values shown on your notice directly to your local county tax appeal board (CTAB) rather than using our informal review process. If you choose to appeal directly to the CTAB, you must submit your appeal to your county clerk and recorder within 30 days from the date on your classification and appraisal notice.

If you disagree with the department's decision after the informal review process, you may appeal our decision with a county tax appeal board (CTAB) in the county where the property is located.

The County Tax Appeal Board (CTAB) is an independent board appointed by the county commissioners and not connected to the Department of Revenue. You can learn more about the CTAB process on the Montana Tax Appeal Board's Appeal Process page.

The Montana Tax Appeal Board (MTAB) is an administrative board tasked with providing an independent and neutral review of the Department of Revenue's property valuation. Board members are appointed by the governor.

MTAB decisions are final unless you pursue district court action.

You can learn more about MTAB and the appeals process on the Montana Tax Appeal Board website.

To appeal decisions made by the Montana Tax Appeal Board, you need to file with a district court.

Payment of Taxes Under Protest

In order for a protest of property taxes to be valid, a taxpayer must have done one or more of the following:

  • filed a Request for Informal Classification and Appraisal Review (Form AB-26) with the Department of Revenue
  • filed a Property Tax Appeal Form with the County Tax Appeal Board
  • filed a Property Tax Appeal Form with the State Tax Appeal Board
  • filed an appeal with the District Court

Montana law, 15-1-402, MCA, requires property owners to file a written protest with the county treasurer and pay the disputed property taxes under protest by the tax payment due date.

Property taxes must be paid before they become delinquent and a written protest is required in order for taxpayers to be eligible to receive any refund and accrued interest if a valuation adjustment is made to their property assessment.

Contact the county treasurer for more information on how to file a written protest of property taxes.