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.
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.