Troubleshooting 404 Errors on ATTOM API Endpoints

Receiving a 404 "Not Found" error when calling an ATTOM API endpoint is one of the most common issues developers encounter. There are several distinct causes, and identifying the right one will help you resolve it quickly.

1. The Endpoint Is Not Included in Your Subscription

A 404 response does not necessarily mean you lack access — that would typically return a 401 Unauthorized. However, some endpoints are only available on specific subscription packages or as add-ons, and calling one outside your plan can still result in a 404.

Common examples of package-gated endpoints include:

• /transaction/salestrend — included in the Premium Property Package and above

• /preforeclosuredetails — included in the Premium Property Package; also available on PAYGO

• /parceltiles — requires the separate Parcel Tile Package add-on

• /transportationnoise — requires the Transportation Noise Package

• /property/buildingpermits — requires the Building Permit Package

If you are unsure which endpoints are included in your plan, contact datacustomercare@attomdata.com. To add endpoints or packages to your existing subscription, your Account Manager can provide pricing and arrange an amendment.

2. You Are Using an Incorrect or Outdated Endpoint Path

ATTOM has multiple API versions, and using a path from outdated documentation is a frequent cause of 404 errors. Always verify the correct path in the current developer documentation at api.developer.attomdata.com/docs.

Some common path corrections:

Note that some endpoints (such as boundary detail) require a geoidv4 identifier rather than an attomId. Using the wrong identifier type will result in a 404. You can retrieve a geoidv4 from the /geoid/lookup endpoint or from the response of other property calls.

3. You Are Using an Incorrect GeoID Format

For geographic endpoints such as Sales Trend, ATTOM uses a V4 GeoID structure. Older-style GeoIDs (e.g., CO06037 or ST36) are not valid for V4 endpoints and will return a 404.

To look up the correct V4 GeoID, use the Location Lookup endpoint:

GET https://api.gateway.attomdata.com/v4/location/lookup?name=<CityName>&geographyTypeAbbreviation=<Type>

Valid values for geographyTypeAbbreviation are documented in the Area API section of the developer docs.

4. Missing or Incorrect Required Parameters

Some endpoints return a 404 when required parameters are missing or when unsupported parameters are passed. For the Sales Trend endpoint, the minimum required parameters are:

• geoIdV4 — a valid V4 geographic identifier

• interval — defaults to yearly

• startyear

• endyear

Always refer to the developer documentation for the full list of required and optional parameters for each endpoint.

The interactive "Try it out" feature on the ATTOM developer portal (api.developer.attomdata.com/docs) can sometimes return 404 errors even when the underlying API endpoint is functioning correctly. This is a known issue with the dev portal itself.

Workaround: Test your API calls directly using a tool such as Postman or a curl command. Pass your API key in the request header:

curl -X GET "https://api.gateway.attomdata.com/<endpoint>" \
  -H "apikey: YOUR_API_KEY" \
  -H "Accept: application/json"

Still Getting a 404?

If you have verified your endpoint path, parameters, and GeoID format and are still receiving a 404, contact ATTOM technical support at datacustomercare@attomdata.com and include:

• Your full request URL (with query parameters)

• The complete response body

• Your API key (or the last few characters if you prefer not to share the full key)

The support team will replicate the call and help identify whether the issue is related to the request format, endpoint routing, or subscription entitlement.