Guide 01 · Los Angeles County
How to find a Los Angeles County AIN
An Assessor Identification Number, usually called an AIN, is the 10-digit identifier Los Angeles County uses to organize an assessor parcel record. It is one of the cleanest ways to make sure you are looking at the intended parcel when addresses are abbreviated, repeated, or formatted differently across systems.
or tax bill
Where to find it
The AIN may appear on a Los Angeles County assessment notice, a property-tax bill, an assessor parcel map, or an agency property-search result. It is sometimes written with punctuation or spaces. For propOPEN, enter the digits only or search the street address first.
A reliable workflow
- Start with the full situs address: street number, street name, city, and ZIP if available.
- Confirm that the returned address and city match your target property.
- Use the AIN to cross-check the record in the County Assessor and Property Tax portals.
- For boundaries or location, compare the result with an official parcel map rather than relying on a pin alone.
What an AIN can and cannot tell you
An AIN helps connect records for a particular tax parcel. It does not establish the current legal owner, grant access to protected information, prove that an address belongs to a particular parcel, or replace a title report. A parcel may also have multiple buildings, units, or addresses; always read the underlying record.