assessor's office

Assessor's Parcel Number Search

An assessor's parcel number is a unique number that a county assessor's office assigns to each parcel of property in a county (some counties such as San Francisco refer to this as a block and lot number).

Each assessor's office has a computer terminal with a numerical index by parcel number for looking up detailed information on a piece of property.

The listing for each parcel should include the:

  • street address
  • name of the owner
  • mailing address for the owner (which may be different from the address of the parcel of property)
  • assessed value of the property

Note: you'll have to go to the assessor's office in person to find the name of the owner. You cannot find ownership information online.

Often a deed number also will be listed, which is a reference to a property deed filed with the county recorder's office when the current owner purchased the property.

Sample Parcel Number Search

To search an assessor's parcel number, go to the Contra Costa County Assessor's Office online map for addresses and parcel numbers


On the right click on the link for Locate parcel by APN

Type a parcel number into the APN search box, such as:


At the new page click on Default Report at the top right to see the street address for this parcel:

100  Gregory Lane, Pleasant Hill

(which is the address for the Pleasant Hill City Hall)

The assessed value of this property is also listed lower down on the page, and a parcel map for the property is to the right.