Multiple ATTOM Records Sharing the Same Property Address

Last updated: September 1, 2026

Multiple ATTOM Records Sharing the Same Property Address

It is possible to encounter multiple ATTOM records that share the same property address but have different parcel numbers and ATTOM IDs. This article explains why this occurs and what steps you can take.

Why Do Multiple Records Share the Same Address?

There are several common reasons this can happen:

  • Missing unit information: For multi-unit buildings (such as condominiums), the source assessor file may not include unit numbers in the site address fields (PROPERTYADDRESSUNITPREFIX and PROPERTYADDRESSUNITVALUE). As a result, all individual units appear with the same base street address, even though each unit is a distinct property with its own unique parcel/folio number and ATTOM ID.

  • Incorrect address in source data: One or more of the records may have an incorrect address due to an error in the original county assessor source data. In these cases, the correct address can be verified against the county assessor's website and a correction can be requested from ATTOM.

  • Legitimate shared address: In some cases, two distinct parcels (e.g., one residential and one agricultural) may genuinely share the same situs address according to county records. This is not an error.

Records Are Not Duplicates

When multiple records share the same address, they are generally not duplicates. Each record represents a distinct property or parcel, uniquely identified by its ATTOMID and parcel number. The shared address is typically a data gap in the source assessor file rather than a sign of duplicate records.

Recommended Approach: Use ATTOMID as the Primary Key

To reliably distinguish between individual properties—regardless of whether their addresses are identical—always use the ATTOMID as your primary key in any downstream joins, pipelines, or reporting. Relying solely on the address string to identify unique properties can lead to records being incorrectly merged or matched.

How to Report an Address Discrepancy

If you believe one or more records have an incorrect address (i.e., the address in the ATTOM data does not match what is shown on the county assessor's website), you can report this to ATTOM Support for investigation and correction. When submitting a request, please include:

  1. The ATTOM ID(s) and/or parcel number(s) of the affected records

  2. The address currently shown in the ATTOM data

  3. The correct address as shown on the county/assessor website

  4. A link to or screenshot of the county assessor record, if available

Once verified, ATTOM's data team will correct the address, and you will receive the updated record in your next scheduled file update delivery.

Records with a Blank Address After Correction

In some cases, after an address correction is applied, a record may end up with a blank address. This means the parcel exists in the source data but has no valid site address. ATTOM does not treat such records as deletions—the record remains in the dataset with an empty address field. How you handle such records in your own system (e.g., whether to exclude or flag them) is at your discretion.

If you have questions about a specific address discrepancy or need to report an issue, please contact datacustomercare@attomdata.com.