Property Tax Terminology



A | B | C | D | E | F | H | I | J | L | M | N | O | P | R | S | T | U | W


Abatement - An official reduction or invalidation of an assessed valuation after the initial assessment for ad valorem taxation has been completed.

Abatement and refund procedure - In lieu of the protest and adjustment procedure, a taxpayer may file an abatement and refund petition for a prior tax year. These petitions must be filed within two years after January 1 of the year following the year in which taxes were levied. For instance, tax year 2021 petitions must be filed no later than January 2, 2024, the first business day of 2024. If the abatement and refund petition is not granted by the assessor, a hearing will be scheduled before a referee who will make a recommendation to the board of county commissioners. A denial by the board of county commissioners may be appealed to the Board of Assessment Appeals.

Actual value - “Actual value” is synonymous with market value. Statutory and constitutional provisions state that actual value of real property for property tax purposes shall be that value determined by appropriate consideration of the cost, market, and income approaches to appraisal. Case law defines “actual value” as “what a willing buyer would pay a willing seller under normal economic conditions.” Multiplying the actual value of a property by the assessment rate produces an assessed value, which multiplied by the tax rate (or mill levy) then produces the amount of property taxes due.

Appraisal - The act or process of developing an opinion of value; an opinion of value, sometimes contained in a written report.

Appraisal approach - A systematic process of developing an opinion of value. Depending on the nature of the property, three approaches may be applied: sales comparison, income capitalization, and cost approach.

Appraisal date - The date on which the appraisal or review opinion applies. For ad valorem property tax purposes, a property is valued as of an appraisal date of June 30 of even years using market data from a minimum of 18 months before and a maximum of 60 months before. Also referred to as the effective date of value or valuation date.

Assessed value - The value of real property according to the tax rolls in ad valorem taxation. The assessed value is the product of the market value of a property multiplied by an assessment rate. The assessment rate is dependent on the property’s classification.

Assessment date - January 1 of the tax year at issue is the assessment date for that year. Per Colorado statute, property must be appraised and classified according to its physical characteristics and condition on January 1. Appraised values reflect the status of the property and any partially completed construction as of this date.

Assessment rate - A percentage dependent on the classification of property applied to determine property taxes. The market value of a property is multiplied by the assessment rate to arrive at an assessed value.

Assessor - A government official who makes assessments for purposes of taxation. County assessors are charged with discovering, listing and valuing real and personal property for tax purposes.

Assessors’ Reference Library (ARL) - A series of three manuals and a statutory index that address Colorado property assessment, authored by the Division of Property Taxation. The provisions of the ARL are binding on assessors, and entitled to deference by the Board.


Base period - A data collection period used for property assessment, required by statute. The base period for a given tax year consists of the 18 months immediately prior to July 1 of the year before the assessment date. In some circumstances, information within the five-year period immediately prior to July 1 of the year before the assessment date may be used. Information relating to conditions which exist outside the base period are irrelevant to the question of valuation and may not be considered by the Board.

Board of County Commissioners - A board of elected county officers charged with the management of various county affairs. A board of county commissioners issues the final county-level decision in an abatement and refund property taxation appeal.

Burden of persuasion - A party’s duty to convince the fact-finder to view the facts in a way that favors that party. In a case before the Board of Assessment Appeals, the petitioner’s burden is “by a preponderance of the evidence.”

Burden of production - A party’s duty to introduce enough evidence on an issue to have that issue decided by the fact-finder, rather than decided against the party in a peremptory ruling such as a summary judgment. “Meeting the burden of proof” means that a party has introduced enough compelling evidence to reach the standard defined in the burden of persuasion, which in Board proceedings is “by a preponderance of the evidence.”

Burden of proof - A party’s duty to prove a disputed assertion. The burden of proof has two components: the burden of persuasion and the burden of production. In a hearing before the Board, the burden of proof is on the taxpayer to show that the Assessor’s valuation or classification of a property is incorrect.


Calculating Property Taxes - Actual Value x Assessment Rate = Assessed Value x Tax Rate = Taxes

Actual Value: Market Value
Assessment Rate: A percentage dependent on the property classification
Assessed Value: The value on which a property is taxed
Tax Rate: Levies imposed by taxing districts, aka mill levy

For example, your home’s market value is $500,000. The assessment rate is 8% as shown on the Notice of Valuation. Your home’s assessed value is $40,000. Your mills are 98 (or 9.8%, or .098). Therefore, your taxes owed are $3,920.

$500,000 x .08 = $40,000 x .098 = $3,920

Classification - The act of segregating property into two or more classes for the application of different effective tax rates. Taxable real property is classified as residential, commercial, industrial, agricultural and vacant land.

Closely held entity - A closely held entity is an entity with no more than three owners. An officer of a closely held entity may represent the entity before the Board of Assessment Appeals if the amount of tax in controversy is less than $15,000 per year.

Closing argument - A lawyer’s or party’s final statement to the Board of Assessment Appeals, in which the lawyer or party requests the Board to consider the evidence and apply the law in their favor.

Comparable sales - Similar property sales, rentals, or operating expenses used for comparison in the valuation process.

Continuance - The postponement of a hearing to a future date at a party’s request and granted at the Board’s discretion.

County Board of Equalization - Generally, appointed hearing officers who conduct hearings and issue recommendations on valuation or classification protests, which will be considered and acted on by a county’s board of county commissioners.

Cost approach - A set of procedures through which a value indication is derived for the fee simple estate by estimating the current cost to construct a reproduction of (or replacement for) the existing structure, including entrepreneurial incentive or profit; deducting depreciation from the total cost; and adding estimated land value. Adjustments may then be made to the indicated value of the fee simple estate in the subject property to reflect the value of the property interest being appraised.

Cross examination - The questioning of a witness at a hearing by the party opposed to the party in whose favor the witness has testified.


De novo hearing - A reviewing decision-making body’s decision of a matter anew, giving no deference to the lower decision-making body’s findings. A new hearing of a matter.

Direct examination - The first questioning of a witness in a hearing, conducted by the party who called the witness to testify. Often shortened to direct.

Discovery - Compulsory disclosure, at a party’s request, of information that relates to the controversy. The primary discovery devices are interrogatories, depositions, requests for admissions, and requests for production.

Division of Property Taxation - A statutorily created state body which coordinates and administers the implementation of property tax law throughout the state and operates under the leadership of the property tax administrator. The Division prepares and publishes manuals, instructional materials and conducts appraisal training, and provides assistance to taxpayers and counties on certain matters. The Division also values public utilities.

Docket number - A number that Board staff assigns to an appeal as a case identifier.


Equalization - The process by which an appropriate governmental body attempts to ensure that all property under its jurisdiction is assessed at the same assessment ratio required by law.

Evidence - Something (including testimony and documents) that tends to prove or disprove the existence of an alleged fact.

Exemption - Properties owned and used for religious, charitable and private school purposes may qualify for an exemption from property taxation. The Division of Property Taxation is responsible for determining qualification for exempt status. Article X of the Colorado Constitution provides that all property is taxable unless declared exempt by the Constitution.

Exhibit - A document, record, or other tangible object formally introduced as evidence at a hearing. Also, a document attached to and made part of a pleading, motion, or other instrument.

Expert witness - A witness qualified by knowledge, skill, experience, training or education to provide a scientific, technical, or other specialized opinion about the evidence or a fact issue.


Filing fee - A petition for appeal to the Board of Assessment Appeals must be accompanied by a nonrefundable filing fee. The amount of the fee is set by statute.

Final agency order - An order that resolves the entire case and terminates the proceedings.


Hearing - At the Board of Assessment Appeals, a quasi judicial session, open to the public, held for the purpose of deciding issues of fact or of law, sometimes with witnesses testifying.


Improvement - A building or other relatively permanent structure or infrastructure (e.g., sewer lines, water lines, roads) located on, or attached to, land.

Income capitalization approach - Specific appraisal techniques applied to develop a value indication for property based on its earning capability and calculated by the capitalization of property income.

Interim agency order - Any order other than a final order.

Intervening years - The even-numbered years in which assessors generally do not revalue real property (absent limited circumstances), and in which the value will stay the same as it was in the preceding odd-numbered year, under Colorado’s two-year valuation cycle for property tax purposes. Odd-numbered years are re-valuation years, and even-numbered years are referred to as intervening years.


Jurisdiction - The Board’s power to decide a case or issue an order. The Board’s jurisdiction is governed by statute. The Board has jurisdiction over property tax appeals from county boards of equalization, county boards of commissioners, certain decisions of the property tax administrator, and decisions of assessors if the assessor or county board of equalization fails to respond to a taxpayer appeal.


Lay witness - A witness who does not testify as an expert and who is therefore restricted to giving an opinion or making an inference that is based on firsthand knowledge and is helpful in clarifying the testimony or in determining facts.

Level of value - The actual value of taxable real property for the one-and one-half-year period immediately prior to July 1 of the year before the assessment date. A level of value must be adjusted to reflect market conditions as of June 30 appraisal date.


Market approach - A valuation technique that provides an indication of value by comparing the subject with identical or similar assets for which price information is available.

Market value - Broadly, what a willing buyer would pay a willing seller under normal economic conditions. The most probable price, as of a specified date, for which the specified property rights should sell after reasonable exposure in a competitive market under all conditions requisite to a fair sale, with the buyer and seller each acting prudently, knowledgeably, and for self-interest, and assuming that neither is under undue duress.

Mass appraisal - The process of valuing a universe of properties as of a given date using standard methodology, employing common data, and allowing for statistical testing. Often associated with real property tax assessment valuation.

Mill levy - A tax applied to real property whereby each mill represents $1 of tax assessment per $1,000 of the property’s assessed value. The total mill levy is comprised of a county and school district levy, and other levies imposed by taxing districts such as special districts. All levies applicable to a property are added together to calculate the total mill levy and total property taxes due.

Motion - A written or oral application requesting the Board to make a specified ruling or order.


Notice of determination - A county assessor’s decision on a taxpayer's appeal of an assessor’s notice of valuation.

Notice of valuation - A statement setting forth the county assessor’s valuation of land and improvements or personal property. Each year, county assessors must send all property owners a notice of valuation (NOV) by May 1st for real property and by June 15th for personal property. A protest form is included with each NOV.


Opening statement - At the outset of the hearing, an advocate’s statement giving the Board a preview of the case and of the evidence to be presented.

Order - A written direction or command delivered by the Board. Includes final orders as well as interim orders.


Petition - A formal written request for appeal filed with the Board.

Petitioner - The party who presents a petition to the Board, or on whose behalf an attorney or agent submits a petition, seeking relief on appeal. The taxpayer.

Preponderance of the evidence - The greater weight of the evidence, established by evidence that has the most convincing force; superior evidentiary weight that, though not sufficient to free the mind wholly from reasonable doubt, is still sufficient to incline a fair and impartial mind to one side of the issue rather than the other.

PIN number - A set of letters and numbers that may be used by an assessor’s office to identify property. A notice of valuation will contain a property identifier such as a PIN number.

Pro se - One who represents oneself in a legal proceeding without the assistance of a lawyer. A self-represented party.

Property tax - Tax paid on owned real or personal property. A county assessor determines the actual market value of property, the Colorado Legislature sets the assessment percentage, and the taxing agencies set the mill levies. The assessed value of a property multiplied by the total mill levy applicable to the property produces the amount of property tax due. The Colorado property tax system provides revenue exclusively for local government services.

Property Tax Administrator - The Property Tax Administrator directs the Division of Property Taxation and coordinates the implementation of property tax law throughout Colorado’s sixty-four counties. Appeals to the Board of Assessment Appeals from the Property Tax Administrator include state-assessed appeals, exemption denial appeals, and appeals of abatements approved by a county but denied by the Division of Property Taxation.

Protest and adjustment procedure - A method of appealing an assessor’s real property valuation or classification by filing a protest with the assessor to a notice of valuation.

Protest period - The time period between May 1 and June 1 of every year for real property, and between June 15 (postmark) and July 5 (in person) of every year for 6 business personal property, during which a taxpayer may file a protest with the assessor of the property’s valuation or classification.


Reassessment cycle - The two-year cycle under which property is valued in Colorado for property tax purposes. Odd-numbered years are re-valuation years, and even-numbered years are referred to as intervening years. Real property may be re-appraised in even-numbered years under statutorily enumerated limited circumstances.

Rebuttal - The time given or evidence presented at hearing for a party to counter the other side’s arguments.

Redirect examination - A second direct examination, after cross-examination, the scope ordinarily being limited to matters covered during cross-examination. Often shortened to redirect.

Refund - As part of the abatement and refund procedure, a return of money by the county Treasurer to a person who overpaid property taxes.

Reply - A party’s reply to an opposing party’s response to a motion.

Rescheduling - The postponement of a hearing to a future date on the Board’s own initiative.

Respondent - The party against whom an appeal is taken, or against whom a motion or petition is filed. At the Board, the Respondent will be a county board of equalization, county board of county commissioners, or the Division of Property Taxation.

Response - A party’s response to an opposing party’s motion.

Rule 11 - A Board rule governing witness list and evidence exchange before hearing. Sometimes the Board or parties will refer to the disclosed exhibits themselves as “Rule 11” or “Rule 11 documents.”


Sales comparison approach - The process of deriving a value indication for the subject property by comparing sales of similar properties to the property being appraised, identifying appropriate units of comparison, and making adjustments to sale prices (or unit prices, as appropriate) of the comparable properties based on relevant, market-derived elements of comparison. The sales comparison approach may be used to value improved properties, vacant land, or land being considered as though vacant when an adequate supply of comparable sales is available.

Schedule number - An identifying number assigned to property by assessors. A notice of valuation will contain a property identifier such as a schedule number.

Service - The formal delivery of legal process, pleading, or notice to a party in the case. Service may be by mail or by electronic means.

Site-specific appraisal - As compared to mass appraisal, the process or resulting written report valuing a single property as of a given date.

Stipulation - A voluntary agreement between opposing parties. The Board accepts written stipulations in resolution of appeals.

Subject property - The property that is appraised in an assignment, or is the subject of the appeal.

Subpoena - An order commanding a person to appear before the Board, or to provide information or specified documents to the Board.


Tax agent - A professional agent who may represent taxpayers in proceedings at the Board of Assessment Appeals.

Tax rate - The factor used to calculate the total tax for a property, typically expressed in dollars per $1,000 (mills) of assessed value. Synonymous with mill levy.

Testimony - Evidence that a competent witness under oath or affirmation gives at hearing or in an affidavit or deposition.

Time trending - A process by which an adjustment is made to sales data to account for changing market conditions. Colorado law requires assessors to analyze sales data to determine if any differences exist between market conditions at the time of a comparable sale, and the valuation date for the property being appraised. Depending on market conditions, the assessor may adjust the comparable sales price, resulting in an estimate of what the comparable would have sold for on the subject’s valuation date.


USPAP - The Uniform Standards of Professional Appraisal Practice is the generally recognized ethical and performance standards for the appraisal profession in the United States. USPAP contains appraisal standards for real property, mass appraisal, and personal property.


Withdrawal - A motion or appeal’s removal from the Board’s consideration.

Witness - Someone who gives testimony under oath or affirmation in person, by deposition, or by affidavit. 

These definitions are provided as an aid to parties appearing before the Board of Assessment Appeals, but are not intended to be comprehensive or to be substitute for legal advice. Certain definitions are drawn in whole or part from the Appraisal Institute, The Dictionary of Real Estate Appraisal (6th ed., 2015) and Bryan A. Garner, Editor in Chief, Black’s Law Dictionary (11th ed., 2019).


Was this content helpful?