Why was a lead not automatically assigned to a site?

Last updated: October 19, 2026

Context

When a lead source uses the Auto assignment method, Delfa assigns each new lead to the nearest site(s) based on the lead's zip code or postcode. Sometimes a lead arrives without a site.

Answer

A lead is only matched when Delfa can locate its postcode and find an active site within your Maximum Distance in the same country. Check the following:

  1. The lead has a postcode. Webforms must include a zip code field for auto-assignment to work.

  2. Each site has a Country and Postal Code. Open the site and check both fields. Sites without them are skipped.

  3. The site's country is supported. Auto-assignment supports the United States, the United Kingdom and most European countries.

  4. The lead is in the same country as the site. A postcode from another country does not match.

  5. The site is close enough. Sites farther than Maximum Distance (50 miles by default) are skipped. Increase it on the lead source if needed.

  6. The site is active. Inactive sites are not considered.

Delfa accepts common postcode formats, with or without spaces and in upper or lower case. US ZIP+4 codes and UK postcodes without a space are accepted. If Delfa does not recognise a full postcode, it may use the surrounding postcode area instead.

Delfa assigns up to Maximum Number of Sites (1 by default), nearest first. If Assign lead to all studies at the matched site(s) is ticked, the lead is also assigned to every active or upcoming study at those sites.

If a lead was not matched, you can assign a site manually. If none of the above explains it, contact the Delfa support team.