Cook County Parcel Owners - Names & Mailing Addresses

Every parcel in Cook County has an address the Assessor's office mails assessment notices to - and the party that mail goes to is frequently not the owner on title. This actor turns that file into a charged-per-record search, filter and aggregate tool over the county's parcel address roll: find a parcel by PIN, search the owner of record or the taxpayer of record, filter by city, ZIP or mailing state, or aggregate a whole roll.

Built for: title and lien research, absentee-owner and out-of-state-holder work, skip tracing against a county's own mailing record, portfolio and servicer mapping, and anyone who needs the county's parcel-to-name mapping without paging a viewer one PIN at a time.

What it covers

1,863,562 parcels in the newest roll (2026), drawn from a 50,671,416-row file that stacks 28 assessment years, 1999 through 2026 (1.62M-1.86M parcels per year, the roll growing over time). Query one year by default; ask for another, or aggregate across the whole stack.

Each record carries two parties and two addresses:

• the owner of record - name plus full mailing address (street, city, state, ZIP)
• the taxpayer of record - the party the assessment notice is addressed to, plus its own full mailing address
• the property - situs street address, city, state, ZIP
• both PIN forms (14-digit and 10-digit) for the same parcel

The fine print that matters

The owner and the taxpayer are two different parties, and collapsing them would misdescribe a third of the county. Measured on the 2026 roll, they differ on 612,891 of 1,863,562 parcels (32.9%) - because the notice goes to whoever services the loan or holds it in trust, not necessarily to the person on title. Both are returned, each with its own address block.

That difference is the point: because the mailing address travels with the taxpayer, the two blocks together answer what the situs address alone cannot - where the party on title actually receives mail. On the 2026 roll, 65,391 parcels are mailed outside Illinois; searching mailState=FL returns Barrington parcels whose notices go to Delray Beach and Ponte Vedra Beach.

Two data notes. The taxpayer of record is blank on 113,800 parcels - a situs address with no mailing party on record, which is a real state, not a defect. And a PIN is unique within a year: the year is part of the parcel's identity in this file, so the same PIN appears once per roll across the 28-year stack.

Typical questions

• "Every parcel owned by a given name or entity."
• "Parcels whose taxpayer of record is a bank or trust - the serviced and trust-held inventory."
• "Parcels in Evanston or ZIP prefix 60010."
• "Absentee owners: parcels whose mail goes to Florida (or any out-of-state address)."
• "A single parcel by PIN."
• "Aggregate by city, ZIP, taxpayer mailing state, or across all 28 tax years."

Inputs

Input	What it does
mode	rows (default) / aggregate
owner	owner-of-record name substring
taxpayer	taxpayer-of-record name substring (servicers, trusts, estates)
pin / pin10	exact parcel id, 14- or 10-digit form
city / zip	situs city substring / ZIP prefix
mailCity / mailState	where the taxpayer's mail goes - set a non-IL state for absentee owners
year	1999-2026; blank = newest roll
groupBy	aggregate over city / zip / taxYear / taxpayerState
maxResults	cap records (default 50)

Default run = 50 parcels from the newest roll - fast for the daily auto-test, and it does not scan the 28-year stack. For a targeted query add a filter; for a broad view use aggregate.

Example inputs

One parcel by PIN - the exact 14-digit parcel index number.

{ "pin": "01011000020000" }

Absentee owners - mailState is where the taxpayer's notice is mailed, so a state other than IL surfaces parcels whose notices are sent out of state.

{ "mailState": "FL", "maxResults": 5 }

Parcels in Evanston

{ "city": "EVANSTON", "maxResults": 5 }

How the roll splits by city - one row per situs city.

{ "mode": "aggregate", "groupBy": "city" }

Low cost

From $0.0001 per record, down to $0.00006 at Gold Pay-per-event: you are charged per record delivered, and nothing for the query. Cost scales with what you pull, not with the size of the file, and each record is metered individually - pulling a ZIP's worth of parcels costs a fraction of a cent.

Example output

One parcel - pin=01011000020000 returns the owner of record, the taxpayer of record and the property address below:

{
  "platform": "cook-parcel-owners",
  "source": "cook-county-parcel-addresses",
  "mode": "rows",
  "groupKey": "",
  "groupCount": "",
  "groupBy": "",
  "pin": "01011000020000",
  "pin10": "0101100002",
  "taxYear": "2026",
  "propertyAddress": "231 W MAIN ST",
  "propertyCity": "BARRINGTON",
  "propertyState": "IL",
  "propertyZip": "60010",
  "ownerName": "ACCNZ LLC",
  "ownerAddress": "5277 TRILLIUM BLVD",
  "ownerCity": "HOFFMAN ESTS",
  "ownerState": "IL",
  "ownerZip": "60192",
  "taxpayerName": "ACCNZ LLC",
  "taxpayerAddress": "5277 TRILLIUM BLVD",
  "taxpayerCity": "HOFFMAN ESTS",
  "taxpayerState": "IL",
  "taxpayerZip": "60192",
  "sourceUpdatedAt": "2026-09-15"
}