Assessor

This article breaks down what the Maricopa County AZ Assessor does for residents and businesses, how valuations and classifications work, the role of appeals and relief programs, and the most effective ways to use county-provided tools to find parcel data, file forms, and get questions answered. It’s written for property owners, prospective buyers, renters, and business operators who want clear, practical guidance on navigating assessments, program eligibility, and updates to ownership or mailing information.

Understand the Maricopa County AZ Assessor’s role and why it matters

The county assessor is responsible for locating, identifying, and valuing all taxable property within Maricopa County. This work underpins the allocation of the property tax burden used by other county and local jurisdictions to fund schools, safety services, flood control, libraries, and health care. The office notices values, maintains ownership and parcel maps, applies legal classifications and exemptions, and provides appeal pathways if you disagree with an assessment. While the Assessor establishes values and applies exemptions as required by law, the Assessor does not levy taxes, set tax rates, or collect tax payments.

See who leads the office and stay informed about initiatives

To learn more about office leadership, vision, and service philosophy—and to follow updates that can affect how properties are valued—review the profiles and updates under County Assessor on the Your Assessor page. You’ll find the office’s public priorities, team structure, and ways the Assessor is modernizing services to improve accuracy, transparency, and customer experience. Use County Assessor on the Your Assessor page to orient yourself to current leadership and information.

Navigate the office’s divisions and what they do for you

The Assessor’s Office is organized to deliver accurate valuations, clear records, and responsive customer support. Understanding how each division functions makes it easier to route your questions and prepare complete filings.

Administrative Division

This division provides organizational leadership and support so front-line teams can deliver on their mandates. It handles human resources, procurement, budgeting, legislative monitoring, intergovernmental coordination, special districts, and revenue-generating services such as data sales. When you see process or policy updates reflected across the website, forms, or public notices, Administrative Division work is often behind the scenes.

Valuation Relief Program Division

This division runs three critical program areas:

Personal Exemptions (such as widow, widower, and disability exemptions) and the Senior Valuation Protection Program that can stabilize or reduce property tax exposure for eligible residents.

Organizational Exemptions for qualifying historic, religious, government, and other property types.

Public Assistance, which helps residents navigate eligibility, documentation, and filing.

If your household’s circumstances or an organization’s mission may qualify for relief under Arizona statutes, you’ll interact with this group. For an overview of program categories and requirements, start at Valuation Relief Programs on the Valuation Relief page.

Information Technology Division

IT powers the office’s online services—application development and support, database management, systems administration, and public-facing tools. The division also builds and maintains the Assessor’s GIS systems, enabling map-based parcel research for the public and county partners. New assessment systems and geospatial tools are incubated here, so improvements in speed, accuracy, and usability often originate in this group.

Property Ownership & Mapping Division

When ownership changes, legal descriptions are recorded, parcel splits or combinations occur, or the county’s parcel fabric needs updates, this division gets it done. It maintains the authoritative parcel layer and produces custom mapping to support appraisers and the public. If you recorded a deed or completed a split, this group’s work will be reflected in the parcel search results and the county’s maps.

Appraisal Division

The Appraisal Division discovers, lists, and values all property types—residential, commercial, agricultural, personal property, and vacant land—using mass appraisal models that follow Arizona Department of Revenue standards. The division reviews building permits, recheck requests, splits, notices of claim, and agricultural applications; it also administers appeals for real and personal property and supports litigation or higher-level appeals. Business Personal Property (BPP) valuers in this division review annual self-reported asset listings and conduct audits where needed.

Use the Parcel Viewer and GIS tools to research your property

For most owners and businesses, the fastest way to verify site details, subdivision boundaries, aerials, and neighboring parcels is to start with the county’s interactive mapping tools.

Explore parcels, aerials, and buffers with the Parcel Viewer

The county’s map-based research tool lets you search by parcel number (APN), owner name, address, subdivision, MCR number, city or ZIP, and even STR (section-township-range). You can also produce radius-based mailing lists for notifications tied to planning or neighborhood outreach. Launch PARCEL VIEWER (MAPS) from the Parcel Viewer to explore layers, measure, print, and export geospatial results.

Deep-dive mapping and spatial data via the GIS Portal

If you need broader county GIS resources—for example, to review countywide flood control or ancillary layers that can inform due diligence—enter through the GIS PORTAL, which hosts additional county geospatial content and services. Find it at the GIS Portal.

Know the valuation foundations: FCV, LPV, legal class, and assessment ratios

Arizona’s property tax system uses terms you’ll see across notices and online records. Understanding them helps you evaluate whether your valuation looks correct and whether an appeal makes sense.

Full Cash Value (FCV) vs. Limited Property Value (LPV)

Full Cash Value is synonymous with market value for assessment purposes (unless a statute prescribes a special method). Appraisers derive FCV using mass appraisal techniques that consider property characteristics, sales patterns, and market behavior.

Limited Property Value is a statutory value designed to limit annual value growth (subject to exceptions). LPV is the basis for most property tax calculations and can rise gradually even if FCV declines—though LPV cannot exceed FCV.

Legal class and assessment ratio

Every parcel is assigned a legal class based on use (primary residence, rental, commercial, agricultural, etc.). Each class has a corresponding assessment ratio used to compute the net assessed value on which jurisdictions apply their tax rates. Mixed-use properties can carry more than one class with a blended ratio.

Rule B adjustments and canvass updates

When permitted construction or canvassing finds changes that alter FCV by 15% or more, the county applies a Rule B calculation to reset LPV to a standardized percentage for that property class. This ensures consistency across similarly used properties. If your LPV is recalculated due to a canvass, review the updated property characteristics and square footage closely and follow the listed appeal window if something looks off.

File smarter: forms, online services, and where to start

Most requests can be initiated online if you know where to look. Start by identifying the task—address change, exemption application, rental registration, appeal—and then jump straight to the relevant form or service.

Change your mailing address

If you’ve moved or need to centralize mail for a trust, submit an address change through the secure portal. Use MAILING ADDRESS CHANGE on the county’s service site to keep notices and tax documents headed to the right place. Start with Mailing address change in the county’s services at the address change portal.

Find the right document quickly

If you’re not sure which form you need, browse the comprehensive index under ALL FORMS. It consolidates appeal forms, agricultural forms, organizational exemption applications, business personal property schedules, rental registration, and more. Open All forms at the Assessor’s All Forms page and use the category filters to locate the correct filing.

When to contact the Recorder or Treasurer

Ownership transfers are recorded with the Recorder’s Office; the Assessor uses those documents to update parcel ownership and legal descriptions. If you need to research deeds or affidavits of value, go to the Recorder’s Office.

Tax rates and collections are handled by the Treasurer’s Office; you can review levy histories, current rates, and payment options there. For county-wide tax levy and rate context that affects your bill, see Tax Levy and Rates at Maricopa County’s tax rates page, and for payments and billing, visit the Treasurer’s Office.

Master the appeal process: when, where, and how to make your case

Appeals are time-sensitive. Your Notice of Value includes the FCV, LPV, legal class, and deadlines. If you believe the value or classification is incorrect, act within the stated window.

Start with the Assessor-level appeal

Use the office’s step-by-step appeal guidance to file an administrative appeal at no cost during the annual appeal period. You can dispute valuation, classification, or factual errors in characteristics. Begin at APPEALS to review instructions, appeal types, and timelines. Go to the Assessor’s Appeals page to get started.

Correct errors with a Notice of Claim

If you discover a factual mistake or misclassification outside the standard appeal cycle, file a Notice of Claim for the current year and up to three prior tax years, as permitted under statute. Use NOTICE OF CLAIM to view eligibility, required documentation, and filing instructions. File through Notice of claim on the Assessor’s site at the Notice of Claim page.

Escalate only if needed

If your administrative appeal is denied or only partially granted, you may appeal to the State Board of Equalization or tax court, depending on the case and timelines. Keep copies of your evidence package—comparable sales or rent rolls, construction permit documentation, appraisals, photos, and correspondence—to support your position if further review is necessary.

Claim exemptions and senior protections correctly

Relief programs exist to ensure fairness for qualifying homeowners and organizations. Each program has distinct criteria, documentation requirements, and filing windows.

Personal exemptions

Qualifying widows, widowers, and people with disabilities may receive partial tax relief. Documentation varies by program and must establish identity, residency, and (if applicable) disability status. Start at PERSONAL EXEMPTIONS within Valuation Relief Programs for eligibility details, evidence lists, and filing steps. Use the Valuation Relief page to review available options.

Senior Valuation Protection Program (SVP)

SVP may stabilize assessed values for eligible seniors who meet age, residency, and income thresholds over a defined lookback period. Keep in mind: the income tests and documentation for SVP differ from those for personal exemptions (e.g., Social Security treatment differs between programs). Read the step-by-step criteria and gather multi-year income documents before filing via the program links found under SENIOR VALUATION RELIEF on the Valuation Relief page.

Organizational exemptions

Nonprofit and qualifying organizations can apply for exemptions or for the reduced assessment ratio associated with Legal Class 9 when property is leased to specific qualifying users (such as churches, veteran’s organizations, or charter schools). Filing windows and documentation are strictly enforced; late filings may require a redemption of waiver process. Review instructions under ORGANIZATIONAL EXEMPTIONS on the same Valuation Relief page.

Register residential rentals and keep records current

Arizona law requires residential rental properties to be registered with the county assessor. Registration ensures accurate classification, compliance with state law, and proper handling of state education tax credits (which do not apply to non-primary residences).

Who must register and how to do it

If a property is used solely as a rental, the owner must register with the county. Out-of-state owners must designate an in-state statutory agent. If the occupant is a qualified family member and the home is their primary residence, classification rules differ from a typical rental. Access registration and verification through the RESIDENTIAL/RENTAL PROPERTY resources, listed under property services, then follow the prompts to search your parcel and complete the registration workflow.

Update promptly after changes

If a rental is converted back to an owner-occupied primary residence—or if agent, mailing address, or contact details change—re-register with the current information through the same portal. Keeping records current prevents misclassification, penalties, or loss of credits for which a property may otherwise qualify.

Get agricultural classification right the first time

Agricultural classification is a statutory valuation intended to reduce taxable burden for commercial agricultural operations that meet strict criteria and are in active production with a reasonable expectation of profit. It is distinct from planning and development “agricultural exemptions,” which involve land-use permitting and are administered outside the Assessor’s scope.

Eligibility basics and documentation

To qualify, operations must demonstrate commercial production and meet the standards in Arizona statutes. The Assessor may require operational information and conducts onsite inspections at least once every four years. Applications received after statutory deadlines are processed for the next available valuation year. Classification can apply in whole or in part; for example, a residence on a farm does not qualify as agricultural, while the active orchard and related boxing facility may qualify.

Respond to requests and canvass letters

Watch for information requests, split letters, or canvass letters sent to operators. Failure to respond can lead to removal from approved status and loss of agricultural classification. If use changes, notify the Assessor within the required timeframe.

Business Personal Property (BPP): report completely and on time

Tangible assets used in a business—machinery, equipment, fixtures—are taxable personal property. Reporting is annual, and the first filing establishes your account; subsequent years use preprinted statements for updates.

How valuation is calculated

The office uses a cost-based approach: original cost (including freight, installation, and sales tax) is multiplied by a statutory valuation factor to derive Full Cash Value; then the class assessment ratio is applied to arrive at Assessed Value. Exemptions for business personal property may apply up to a statutory limit set annually by the state; the exemption applies statewide once per legal entity.

Filing practices that avoid delays

Keep an up-to-date asset list with acquisition year and cost for each item.

Report additions and deletions accurately by year.

Maintain historical cost and dates for assets acquired from another Arizona business to preserve prior depreciation.

File by the April 1 deadline to avoid penalties and ensure notices reflect the latest equipment profile.

For a consolidated view of business personal property forms and instructions, use BUSINESS PERSONAL PROPERTY under the forms index at All Forms.

Common areas, subdivisions, and community associations

If you manage or belong to a homeowners’ association, you may interact with specialized processes for common areas. Parcels intended for shared use—beautification areas, condominium common elements, or airport-use areas—have statutory requirements for deed restrictions and ownership by a qualifying association or corporation. The county provides checklists and forms to consolidate and identify common area parcels appropriately. Submit required materials within stated timelines to ensure values reflect eligible use and to streamline the association’s annual tax administration.

Mobile and manufactured homes: affixed or not makes a difference

Mobile/manufactured homes affixed to real estate are still valued using the personal property depreciation schedule, with the factory list price as the baseline and depreciation applied per state guidance. Non-affixed units are valued similarly but remain on the personal property roll. Prior to moving a mobile/manufactured home, ensure tax clearance and county permitting are in place; Assessor records must be updated with new location and owner details consistent with statutory authority. Appeal timelines differ depending on whether the home is on the real property or personal property roll, so check your valuation notice carefully.

Ownership changes, parcel splits, and map updates

The Assessor maintains parcel ownership and geometry based on documents received from the Recorder’s Office. Ordinary recorded home purchases can take several weeks to be reflected online; complex legal descriptions or metes-and-bounds transactions may take longer.

Best practices for splits and combinations

Work with a title company or attorney to ensure the legal description is precise and consistent with local ordinances and state requirements.

Include the most recent APN on recorded deeds.

Expect activation timelines that vary by volume and complexity; during peak seasons, completion may take longer before new APNs appear as active in both the Parcel Viewer and the Assessor’s website.

Use PARCEL VIEWER HELP to review search and mapping tips that can speed up your research while splits or combinations are processing, accessible from the Parcel Viewer help.

Reports, data, and tax rate context

Whether you’re assembling an appeal package, analyzing market trends for business planning, or preparing notices to neighbors, the county provides curated reports and bulk data options.

Published reports and bulk data access

For curated outputs—such as assessment summaries and program statistics—start at REPORTS. For bulk extracts and API access that integrate directly with your systems, go to DATA SALES to learn about file formats, delivery frequency, and ordering steps. Explore Reports at the Assessor’s Reports page and order bulk data through Data Sales at the Data Sales page.

Countywide tax levy and rate information

Property tax rates are set by governing jurisdictions, not the Assessor. For historic and current levy and rate information that influences your annual bill, the county maintains a centralized page. Review Tax Levy and Rates by visiting the county’s Tax Levy and Rates page to compare districts and understand year-over-year changes.

Communicate with the office and use official help resources

When you need direct assistance—whether for a valuation question, program eligibility, or a website issue—the office provides self-service guidance and an inquiry form that routes requests to the right team.

Find quick answers via FAQ and “How Do I?”

Before submitting a ticket, scan the FAQ and HOW DO I? sections. These pages aggregate the most common questions by topic—agriculture, canvass, corrections, districts, legal class, mobile homes, rental registration, splits, valuation relief—and link to the correct form or program page. Consult the searchable FAQ when you need authoritative, plain-language answers.

Submit a question or schedule help

If you can’t find what you need, use the office’s secure inquiry form. You can describe your topic and upload documents when requested. Access CONTACT US at the office’s service portal here: Contact Us (inquiry).

Departments and Offices

Maricopa County Assessor’s Office — 301 W Jefferson Street, Phoenix, AZ 85003 — (602) 506-3406

Maricopa County Treasurer’s Office — 301 W Jefferson St, Suite 100, Phoenix, AZ 85003 — (602) 506-8511

Maricopa County Recorder’s Office — 301 West Jefferson Street, Phoenix, AZ 85003 — (602) 506-3535

Maricopa County Clerk of the Superior Court — 201 W Jefferson St, Phoenix, AZ 85003 — (602) 372-5375

Maricopa County Board of Supervisors — 301 W Jefferson St, 10th Floor, Phoenix, AZ 85003 — (602) 506-3011

Maricopa County Assessor FAQs

How do I challenge the value or classification shown on my Notice of Value?

If you disagree with the full cash value (FCV), limited property value (LPV), or legal class, you can appeal within 60 days of the mailing date shown on your notice. Start by reviewing the office’s step-by-step guidance to file an appeal that explains deadlines, required forms, and what evidence helps (e.g., recent sales, property characteristics). If you discover a factual error outside the appeal window, you may use a Notice of Claim to correct certain errors for up to three prior years. See file an appeal and the separate Notice of Claim instructions to pick the right path for your situation. Use file an appeal and Notice of Claim.

Where can I look up parcels, boundaries, and aerials for my property?

The Assessor provides an interactive Parcel Viewer with search by APN, owner, address, subdivision, and more. You can draw buffers to export nearby owner lists (CSV), switch basemaps, and check flight-date layers to understand when aerials were captured. Keep in mind: parcel lines are illustrative, not a legal survey, and users should independently verify boundaries with recorded documents or a survey when precision is required. Open Parcel Viewer.

What relief or exemptions are available for seniors, widows/widowers, disabled persons, or qualifying organizations?

Homeowners may qualify for programs that reduce assessed value or stabilize LPV, each with distinct documentation and filing windows. Seniors can apply for valuation protection (with age, residency, and income tests), while personal exemptions may apply for widows, widowers, and persons with disabilities. Organizations may pursue statutory exemptions or Class 9 assessment for certain leases. Review eligibility, income thresholds, and how to apply under Senior Valuation Relief and Personal Exemptions.

I own a rental—do I need to register it with the Assessor?

Yes. Arizona law requires residential rental registration with the county where the property is located. Registration is separate from recording an affidavit and helps jurisdictions enforce health and safety codes. Rentals occupied by qualified family members may be classed differently than those leased to others, which can affect eligibility for the State Aid credit. Start the process from your parcel page using Rental Registration.

How are my property taxes calculated from Assessed Value?

The Assessor determines FCV/LPV and applies the statutory assessment ratio to produce your net assessed value; tax rates are set each year by jurisdictions and applied by the Treasurer. Even when values fall, taxes can rise if levies change (e.g., new bonds, overrides). To see current and historical levies and rates back to 2000, review the county’s official county tax levy and rates page. Use county tax levy and rates.