Sources & Methodology

1. Our Editorial Mission for Sourcing

Every fact on a county page must be traceable back to a primary, authoritative source — almost always the county property appraiser, county assessor, or appraisal district’s own publication, or the relevant state Department of Revenue or property-tax statute. If we can’t show where something came from, we don’t publish it. That principle is the foundation of every other process on this page.

2. Source Hierarchy — Six Tiers

Not all sources are equal. We rank them by authority and start at the top, moving down only when a higher-tier source doesn’t address the question:

3. Tier 1 — County Property Appraiser, Assessor, and CAD Websites

The county office’s own website is the authoritative source for everything specific to that county. Examples we reference (each verified live):

• Miami-Dade County Property Appraiser: miamidade.gov/pa
• Broward County Property Appraiser: bcpa.net
• Hillsborough County (FL) Property Appraiser: hcpafl.org
• Los Angeles County Assessor: assessor.lacounty.gov
• Orange County (CA) Assessor: ocassessor.gov
• Harris County (TX) Appraisal District: hcad.org
• Dallas Central Appraisal District: dallascad.org
• Tarrant Appraisal District: tad.org
• Cook County (IL) Assessor: cookcountyassessor.com
• Maricopa County (AZ) Assessor: mcassessor.maricopa.gov

4. Tier 2 — State Departments of Revenue and Equivalents

For state-level rules, oversight, statewide forms, and exemption amounts set at state level, we reference the state’s revenue or tax authority. Examples:

• Florida Department of Revenue — Property Tax Oversight: floridarevenue.com/property
• California State Board of Equalization: boe.ca.gov
• Texas Comptroller of Public Accounts — Property Tax Assistance: comptroller.texas.gov/taxes/property-tax
• New York State Department of Taxation and Finance — Property Tax: tax.ny.gov/pit/property
• Illinois Department of Revenue — Property Tax: tax.illinois.gov
• Pennsylvania Department of Community and Economic Development: dced.pa.gov
• Maryland State Department of Assessments and Taxation (SDAT): dat.maryland.gov
• Washington Department of Revenue — Property Tax: dor.wa.gov/taxes-rates/property-tax

5. Tier 3 — State Property Tax Codes

For the underlying legal framework — exemption rules, value caps, appeal rights, classification — we reference each state’s property tax statute:

• Florida — Florida Statutes Chapter 193 (Assessments), Chapter 194 (Administrative and Judicial Review), Chapter 196 (Exemption)
• California — California Revenue and Taxation Code (Part 0.5 — Implementation of Article XIII A); Proposition 13 (1978); Proposition 19 (2020)
• Texas — Texas Property Tax Code (Title 1 of the Tax Code)
• Illinois — Illinois Property Tax Code (35 ILCS 200)
• New York — New York Real Property Tax Law (RPTL)
• Massachusetts — Massachusetts General Laws Chapter 59 (Assessment of Local Taxes)
• Pennsylvania — Pennsylvania General Assessment Law and General County Assessment Law
• Ohio — Ohio Revised Code Title 57 (Taxation)

State statutes are typically published at each state’s official legislative site. We link directly where the state publishes a stable URL.

6. Tier 4 — International Association of Assessing Officers (IAAO)

The International Association of Assessing Officers (IAAO) at iaao.org is the professional and standard-setting body for the mass-appraisal profession in the U.S. and internationally. IAAO publishes Standards (Standard on Mass Appraisal of Real Property, Standard on Property Tax Policy, Standard on Ratio Studies, etc.), professional designations (CAE, RES, AAS, MAS, PPS, CMS), and continuing education for the appraiser/assessor community. We reference IAAO Standards for technical methodology and best practice — never as a substitute for a county’s own published procedure.

7. Tier 5 — Lincoln Institute of Land Policy

The Lincoln Institute of Land Policy at lincolninst.edu is a leading non-partisan research body on land and tax policy in the U.S. Its Significant Features of the Property Tax database is widely used by researchers and journalists for inter-state comparisons of exemptions, caps, and assessment practices. We reference Lincoln Institute material for context on how rules differ between states — not as a substitute for the county’s or state’s own publication.

8. Tier 6 — Reputable U.S. Press and Academic Research

For background on a county’s tax climate, recent legislative changes, or sector trends, we reference reputable U.S. business and tax press (Reuters, Bloomberg, Wall Street Journal, regional papers like the Tampa Bay Times, Los Angeles Times, Houston Chronicle), specialty publications (Tax Notes), and academic research from U.S. law and policy schools. Press and academic sources are never the sole source for a current portal URL, deadline, or exemption amount. Anything time-sensitive comes from Tier 1, 2, or 3.

9. URL Verification — How We Stop Broken Links

1. Manual click-through. Every external link is clicked by an editor before publication. We confirm the page loads, the destination matches the topic, and the URL is the canonical one.
2. Official-domain confirmation. County sites are confirmed against the state’s directory of county appraiser/assessor offices to ensure we’re linking to the official site, not a third-party data aggregator with a similar name.
3. Content match. The destination page must actually be the page we describe. A “property search” link that lands on a generic county homepage doesn’t pass — we link to the actual parcel-search tool.
4. HTTPS preference. Where the source publishes both, we link to HTTPS.
5. Live search test. For Tier 1 portals, we run a sample parcel search to confirm the search itself works, not just the page.
6. Quarterly re-verification. Every external link on every page is re-checked at least quarterly.
7. No Google Search fallbacks. If we can’t verify a county’s specific portal URL, we don’t link to a Google Search results page as a substitute. We mark the section as “URL not yet verified” or omit it.

10. Fact-Checking Workflow

Every county page goes through this workflow before publication:

1. Drafter pulls facts from the county’s website, the state Department of Revenue, and the relevant state property tax code. Each fact gets a source note.
2. Editor reads the source pages in full, including any “system maintenance,” migration banners, or “this year’s deadline” notices.
3. Editor cross-checks the office name and terminology against the state DOR’s directory.
4. Sample searches are performed on the Tier 1 portal to confirm the parcel-search description is accurate.
5. Exemption amounts and deadlines are confirmed against the state DOR or state statute where the rule is set at state level.
6. Appeal-window dates are verified against the county’s published schedule.
7. Second editor reviews the page end-to-end before it goes live.
8. “Last reviewed” date is set to the publication date.

11. The Two-Source Cross-Reference Rule

Time-sensitive facts — a portal URL, an appeal deadline, an exemption amount, a notice mailing date — must be confirmed by two independent sources before they go on a page. Acceptable combinations:

• The county’s own page and the state DOR (where DOR publishes the same rule)
• The county’s own page and the state property-tax statute that sets the deadline or exemption
• The state DOR and the state statute (for state-set rules)

If two sources disagree, we go with the more authoritative one for the type of fact: the county for portal mechanics and county-set fees, the state DOR or statute for state-set exemptions and statewide deadlines.

12. Update Cycles — Aligned to the Property-Tax Calendar

U.S. property tax administration runs on a strongly seasonal calendar (January 1 assessment date in many states; spring/summer notices; fall/early-winter tax bills), so review cycles align to that.

13. Citation Standards

• External links open in a new tab with rel="noopener" for security
• Affiliate links use rel="nofollow noopener sponsored" per FTC endorsement guidance
• Primary citations link directly to the county portal, state DOR page, or statute in question
• Statutory references use the standard format (e.g., F.S. §193.155, Cal. Rev. & Tax. Code §218, 35 ILCS 200/15-175) and link to a stable text source where available
• Last-reviewed dates appear on every county page so readers can judge freshness

14. What We Don’t Use

• Property tax consultant marketing pages. We don’t cite a property-tax-protest firm’s blog as authority for a county’s appeal procedure. The county’s own page is the authority.
• Real estate listing sites’ “tax record” tabs. Those are scraped from county data and are often months out of date. We link the county portal directly.
• Anonymous blog posts. Even when factually accurate, anonymous content can’t be verified or held to account.
• Wikipedia as a sole source. Useful for orientation, never as the sole basis for a fact on a county page.
• Generic AI-generated content from other sites. We don’t republish or paraphrase content we can’t trace to a primary source.
• Wayback Machine snapshots in place of current pages. Useful historical reference; never a substitute for the county’s current portal.
• Social media posts from individuals or unofficial accounts, regardless of follower count.
• Out-of-jurisdiction guidance applied across states. Florida’s Save Our Homes cap doesn’t apply in California; California’s Prop 13 doesn’t apply in Texas. We treat each state’s framework separately.
• Commercial property-data resellers (CoreLogic, Zillow, Redfin, ATTOM, etc.) as a substitute for the county’s own portal. Useful for context where they aggregate publicly licensed data, but never the canonical source for county-administered records.

15. Reader Contributions and Corrections

Readers are an important part of our verification system. Property tax consultants, real estate professionals, and homeowners who use these portals daily often spot inconsistencies before our quarterly review catches them. If you spot a discrepancy — a portal redirected to a new URL, an exemption amount that’s been raised, an appeal deadline that’s changed — please email info@property-appraisers.org with subject line “Correction” and the URL of the page in question. The full corrections workflow is on the Editorial Policy page.

16. Audit Trail and Openness

Where a journalist, researcher, or property-tax professional needs to verify how we sourced a particular page, we make our editorial notes available on request. Email us with the URL of the page and the specific factual claim you want to trace, and we’ll respond within seven business days with the underlying source links and editorial notes. Transparency is a feature, not a cost.