Look Up Who Owns a List of Property Addresses

Say you buy small commercial and rental buildings, and a broker has sent you four addresses in four states: one in Avondale, Arizona, one in Oak Lawn outside Chicago, one in Philadelphia and one in downtown Houston. Before you make a single call you want to know who owns each one, whether they live there, what the county thinks it is worth and when it last sold. None of that is secret. It is spread across four assessor offices that each publish it differently.

The manual way, and what it costs

For four addresses the free route works, and if this is a one-off you should take it. Each of the 4 counties has a parcel search: type the address, open the record, copy the owner and mailing address, then find the value and the last sale, which in Cook live in 2 datasets separate from the address one. It is four searches in four different layouts, and it is fine at this size.

It stops being reasonable when the list grows or repeats. Forty addresses is an afternoon, the four counties use four different layouts, and in Cook the column labelled owner is not the current owner: it matched the buyer of a sale since 2023 on 3 of 250 parcels checked on 29 September 2026, while the taxpayer name matched on 201. Copy the wrong column and your list is out of date before you start.

The faster way

US Property Records Export & Owner Lookup (County Assessor) does the same search once and hands back every row at once.

{
  "lookups": [
    "810 S 114th Dr, Avondale, AZ 85323",
    "6224 W 91st St, Oak Lawn, IL 60453",
    "439 Lemonte St, Philadelphia, PA 19128",
    "910 Prairie St, Houston, TX 77002"
  ]
}

One address per line, written the way the broker sent them. The actor works out each address’s county with the US Census geocoder and routes it to that county’s roll, so there is nothing else to fill in. The run behind this article resolved all 4 in 97 seconds; 86 of those were spent downloading Harris County’s 212 MB roll, so a list without a Houston address comes back far faster. Four found properties at $0.045 each is $0.18.

What comes back

The Houston row, from that run:

{
  "query": "910 Prairie St, Houston, TX 77002",
  "query_type": "address",
  "input_index": 3,
  "status": "completed",
  "county": "Harris",
  "parcel_id": "0010570000014",
  "situs_address": "910 PRAIRIE ST",
  "owner_name": "FKM PARTNERSHIP LTD",
  "owner_type": "company",
  "mailing_address": "PO BOX 1074",
  "mailing_city": "BELLAIRE",
  "mailing_state": "TX",
  "absentee_tier": "out_of_city",
  "market_value": 1000000,
  "assessed_value": 600000,
  "year_built": 1882,
  "building_sqft": 7500,
  "last_sale_date": "1997-01-02",
  "last_sale_price": null,
  "source": "Harris Central Appraisal District (HCAD)"
}

Address	Owner	Mails to	Market value	Last sale
810 S 114th Dr, Avondale AZ	J AND L AZ PROPERTIES LLC	Ramsey, MN (out of state)	$331,000	$128,000 in March 2013
6224 W 91st St, Oak Lawn IL	Alberto Munoz	the property (owner-occupied)	assessed $32,000	$290,000 in August 2022
439 Lemonte St, Philadelphia PA	Stefanini Alexander Gabriel TR	Conshohocken, PA (out of city)	$417,200	August 2026, no price recorded
910 Prairie St, Houston TX	FKM Partnership Ltd	Bellaire, TX (out of city)	$1,000,000	title passed January 1997

Three of the four are owned by someone who does not live there, and absentee_tier says which kind. That is the column that decides your first call: the Oak Lawn house is owner-occupied, so a letter to the property reaches the owner, while the Minnesota LLC that owns the Avondale rental has to be reached at its Ramsey address.

What you’d do with it

Export the dataset to CSV and mail-merge from owner_name and the four mailing columns, or paste the list into your CRM with parcel_id as the key. Next month, when the broker sends 40 more, paste them into the same lookups box: there is no per-run limit, and each address that is not found comes back as a free row with error_class and retry telling you whether to fix the address or try again later.

Worth knowing

Values mean different things per county: Houston’s $600,000 is the capped appraised value against a $1,000,000 market value, and Cook publishes assessed value only, 10% of market for a house. Texas does not disclose sale prices, so the Houston row has a title date and no price, and a Philadelphia sale recorded at $0 comes back with no price rather than a fake one. Coverage is 511 counties in 21 states; an address elsewhere returns a free not_covered row, and owner names are withheld by law in California and New Jersey.

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Run it yourself: How to run US Property Records Export & Owner Lookup (County Assessor) walks the whole thing step by step.

Build an absentee owner mailing list for a ZIP code does the opposite job, starting from an area instead of an address list. For the listing side of the same address (the Redfin Estimate, listing history, photos), use Zillow & Redfin Property Data Scraper.