How to Read a Property Index Number

The Cook County websites have a wealth of information on property taxes and all things related.  Here’s a short excerpt from the Cook County Clerk’s site on what a Property Index Number is and how to find it. The full details of this article can be found at

How to Read a PIN

The PIN is a 14-digit number composed of a 10-digit base that is modified for condominiums and leaseholds by adding a four-digit unit suffix. The basic PIN structure is: AA-SS-BBB-PPP-UUUU

  • AA is the AREA number (sequential township)
  • SS is the SUBAREA number (section)
  • BBB is the BLOCK number
  • PPP is the PARCEL number
  • UUUU is the UNIT number for condominiums and leaseholds (zeros in this portion of the PIN indicate non-condo and non-leasehold PINs)

This system uniquely identifies each tax parcel in Cook County and makes it possible for tax map users to quickly locate a parcel on a tax map.


PIN = 12-26-328-009-0000

How Can I look up my PIN

You can find your PIN through an address search on the Cook County website at