APN vs Parcel ID
By AcreBound Editorial Team Updated:
Quick Answer
APN and parcel ID usually mean the same thing: the number a county gives to a parcel of land. Each county picks the label, such as APN, AIN, folio or tax map number.
The trap is a look-alike. An account number, a payment PIN or a map system’s internal ID can sit next to the real parcel number.
APN and parcel ID usually name the same thing: the number a local government gives to a parcel of land. Counties choose their own label, so one site says APN and the next says parcel ID. The risk is a look-alike. An account number, a payment PIN or a map system's internal ID can sit right next to the real parcel number and fool you.
Same Kind of Number, Different Labels
| Label | Where it appears |
|---|---|
| Parcel number (APN) | Maricopa County, AZ assessor |
| Assessor's Identification Number (AIN) | Los Angeles County, CA: ten digits of map book, page and parcel |
| Tax map number, SBL (section-block-lot), print key | New York State tax bills |
| Borough-block-lot (BBL) | New York City tax bills |
| Folio number | Miami-Dade County, FL property appraiser, which searches by folio |
| PIN or PID | Listed with AIN as another name for the APN by a University of California extension program |
These are examples, not a full map of the US. Use whatever term the county in question uses, because that's what its forms and search boxes will say. If you're speaking generally, "parcel number" is understood almost everywhere.
Where the Names Stop Meaning the Same Thing
PIN: parcel number in one place, password in another
In some counties PIN stands for property or parcel identification number. In Los Angeles County it doesn't. The treasurer defines the PIN as a code for electronic transactions, printed on the tax bill, and the assessor says it's generated by the treasurer's office. It doesn't identify the parcel.
Account numbers
Some counties bill by account, and the account number may not match the parcel number. Maricopa County's assessor even lists a separate search for business names and account numbers, which covers personal property rather than land. If a search fails, check that you copied the field labeled for the parcel.
Internal IDs in maps and datasets
A GIS layer may carry several ID fields, including a database key that exists only inside that system. Commercial data providers often add their own persistent record IDs on top of the county's number. Pick the field labeled APN, parcel number or tax parcel number, and treat object IDs and similar fields as plumbing.
Lot numbers and legal descriptions
A lot number comes from a recorded subdivision plat and is one piece of a legal description. The parcel number is the assessor's tracking number. In some counties the lot or plat appears inside the parcel number, which makes the two look related. They are still different records with different jobs. On a deed, the legal description is what defines the land. See Legal Description vs Street Address vs APN.
The same number in two counties
Counties number their parcels on their own, so an identical string of digits can point to two unrelated parcels in two counties. Always search with the county.
Formatting
Advice differs by office. Maricopa's assessor says its search takes the number in any format, with or without separators. New York's tax department says to enter the tax map number exactly as printed, including periods and hyphens. When a search fails, retry both ways, with and without separators, and check for dropped leading zeros, especially after a trip through a spreadsheet.
Quick Check Before You Type a Number
- Does the label say APN, parcel number, parcel ID, AIN, tax map number or folio? Probably the right one.
- Does it say PIN? Look up what that county means by it.
- Does it say account, roll, object ID or record ID? Probably not the parcel number.
Common Mistakes
- Assuming every ID field in a dataset means the same thing.
- Using an account number or a bill PIN as the parcel number.
- Searching a number without the county.
Frequently Asked Questions
Is a parcel ID the same as an APN?
Usually. Both identify a parcel, and the label depends on the county.
Is a parcel number the same as a folio number?
In places that use folios, such as Miami-Dade County, the folio number plays the role of the parcel number.
Is an APN the same as a lot number?
No. A lot number is part of a subdivision plat and legal description. The APN is the assessor's identifier for the parcel.
Is an APN the same as a legal description?
No. The APN is a short number used for tax records. The legal description is the formal text that defines the land in a deed.
Can one property have more than one parcel number?
Yes. A property can include several parcels, and each parcel can have its own number. Check the outline and acreage of every parcel you find.
To find yours, see How to Find the APN for a Property. For the basics, see What Is an APN? and What Is a Parcel Map?
Sources
- Maricopa County Assessor: Frequently Asked Questions Parcel number, search formats, account number search.
- Los Angeles County Treasurer and Tax Collector: General Request for Information AIN and PIN definitions.
- Los Angeles County Assessor: Mapping help Where PINs come from.
- New York State Tax Department: Property tax bill examples SBL, print key, BBL; entering the number as printed.
- Miami-Dade Property Appraiser: Property Search Search by folio.
- UC ANR Informatics and GIS Program: Finding and Using Parcel Data in California AIN, PIN and PID as other names.