Salesforce Duplicate Matching Rules Blocking Web-to-Lead Submissions

Why Web-to-Lead Submissions Are Blocked by Duplicate Rules

For Web-to-Lead form submissions, if a Duplicate Matching Rule is configured to either Block or Allow with Alert, any submission that matches the duplicate criteria is always blocked — even if the rule is set to "Allow." This is because Web-to-Lead operates as an automated process and cannot display the duplicate alert dialog to a user for confirmation. As a result, the default behavior is to block the submission.

Options to Allow Duplicate Leads Through Web-to-Lead

Option 1 — Add a Condition to the Existing Duplicate Rule: Modify your existing Duplicate Rule to add a condition that excludes records where the running user is the default Web-to-Lead creator user. This prevents the Duplicate Rule from triggering on automated Web-to-Lead submissions while still evaluating duplicate matches for records created manually by sales users.
Option 2 — Create a Separate Duplicate Rule for Web-to-Lead: Create a second Duplicate Rule configured to run only when the running user is the default Web-to-Lead creator. Set this rule's action to "Allow and Report" (without the Alert option). This allows duplicate leads from Web-to-Lead to be created and logged in the Duplicate Record Report without blocking the submission.
Option 3 — Use Lightning Record Edit Form: Records added or edited using the Lightning Record Edit Form component bypass the duplicate alert behavior. Consider using this approach for use cases where leads are captured through custom Lightning components.