Assessor's Parcel Number (APN)
An Assessor's Parcel Number (APN) is the unique identifier a county assessor assigns to each parcel of land for property-tax assessment and record-keeping.
What an APN is
Every parcel in the United States is tracked by its county assessor under an APN — also called a parcel number, tax ID, or property ID. The APN ties a specific piece of land to its assessed value, tax bill, and ownership record. Formats vary by county: most encode book, page, and parcel segments (for example 123-456-789), but there is no national standard.
Why the APN matters
Because the APN is the county's primary key for a parcel, it is the most reliable way to pull the correct assessment, zoning, and ownership records — addresses are ambiguous and change, while the APN is stable. Title companies, developers, and investors use it to verify they are researching the exact parcel.
Looking up a parcel by APN in Paxiv
Paxiv maps parcels nationwide with their APN, owner, building, and validated zoning data, and its AI search accepts plain-English questions or a specific APN. Every record links to the authoritative county assessor source, so the APN and its underlying data can be verified in one click. The core platform is free.
Paxiv by the numbers
| Parcel records | 150M+ Parcel records in the nationwide serving table, covering residential, commercial, agricultural, and vacant land. |
|---|---|
| State coverage | All 50 states Every U.S. state is queryable on every tier, including the free one — coverage is not a paid upgrade. |
| City infrastructure coverage | Water, sewer, and storm — mapped per parcel Sourced from municipal GIS, city by city rather than one national feed — the city-level layer most nationwide parcel tools do not carry at all. |
| Free tier | $0, no card, no time limit Includes 15 parcel lookups, 3 zoning reports, 5 AI search credits, 3 skip traces, and 1 deal room. |
| Transaction fees | Zero Paxiv is subscription software, not a brokerage. It takes no commission and never participates in a deal. |
Where this data comes from
Paxiv's parcel, ownership, and zoning records link back to the originating county assessor, county recorder, or municipal zoning code, with flood data from FEMA's National Flood Hazard Layer and geographic reference data from the U.S. Census Bureau — so every figure can be checked against its authoritative source rather than taken on faith.
- County assessor and recorder offices — Parcel boundaries, ownership of record, assessed values, and transaction history. Every record in Paxiv links back to the originating county office for one-click verification.
- City and county zoning ordinances — Zoning classification per parcel, linked to the municipality's own published zoning code so the underlying ordinance can be read directly.
- FEMA National Flood Hazard Layer — Flood zone, Special Flood Hazard Area status, and base flood elevation, resolved by point-in-polygon lookup against FEMA's own published layer.
- U.S. Census Bureau — Census tract containment via the Bureau's official geocoder, plus TIGER/Line geographic reference files.
Frequently asked questions
What is an APN in real estate?
An APN, or Assessor's Parcel Number, is the unique ID a county assessor assigns to a parcel of land for tax and record-keeping purposes. It is also called a parcel number, tax ID, or property ID.
How do I find a property's APN?
You can find an APN on a property tax bill, deed, or the county assessor's website. In Paxiv you can look up any parcel nationwide and see its APN alongside owner, zoning, and building data, each linked to the authoritative county source.
Is an APN the same as a parcel number?
Yes. APN, parcel number, parcel ID, tax ID, and property ID all refer to the same county-assigned identifier for a parcel of land, though the exact name and format vary by county.