What is the lead auto assignment rule?

A Lead Assignment Rule is a built-in Salesforce rule that auto-routes incoming Leads to the right user or queue based on criteria you define — region, industry, lead source, lead score, anything queryable. It runs on Lead create or update so reps see new prospects in their queue without an admin lifting a finger.

What it consists of

• Rule — only one Lead assignment rule can be active at a time.
• Rule entries — ordered list of criteria + action (“if Country = UK and Industry = Healthcare → assign to UK Healthcare Queue”).
• Default rule entry — usually the last, catch-all, that routes anything not matching earlier entries.

Each rule entry sets:

• Order — sequence to evaluate
• Criteria — filter conditions or a formula
• Assigned User / Queue — who gets it
• Email Template — optional notification to the new owner

How a Lead hits the rule

Lead assignment rules fire when:

1. A Web-to-Lead form submits
2. A Lead Import Wizard or Data Loader insert/update runs (only if the “Assign using active rule” option is ticked)
3. An API insert/update sets the useDefaultRule AssignmentRule header
4. A user manually ticks “Assign using active assignment rule” when creating/editing a Lead in the UI
5. An Apex Database.DMLOptions.assignmentRuleHeader.useDefaultRule = true is set before insert

Important: assignment rules do not fire on every save by default — the caller has to opt in (UI checkbox, API header, or DMLOptions). This trips up new admins.

Example rule

Lead Assignment Rule: "Standard Routing"
  Entry 1 (order 1):
    Criteria: Lead.Country = 'India' AND Lead.AnnualRevenue > 10M
    Assigned: Enterprise India Queue
    Notification: "New enterprise lead" email template

  Entry 2 (order 2):
    Criteria: Lead.Country = 'India'
    Assigned: India SMB Queue

  Entry 3 (order 3):
    Criteria: Lead.LeadSource = 'Web' AND Lead.Industry = 'Healthcare'
    Assigned: Healthcare AE Round Robin queue

  Default (order last):
    Criteria: (none — catch-all)
    Assigned: Unassigned Leads Queue

Round robin and load balancing

Out of the box, Salesforce assigns to a specific user or queue per entry — it doesn’t load-balance. Three approaches to round-robin:

1. Queue + sales team works the queue — simplest, lets reps pull leads
2. Custom field counter + assignment rule + Flow — admin-built round-robin
3. AppExchange tool like LeanData, Chili Piper, or Distribution Engine — production-grade routing with skills, capacity, time-zone

Auto-assignment vs auto-response

These are separate features that often run together:

Both can fire on the same Web-to-Lead submission.

Common follow-ups

• Active rules at a time? — One Lead assignment rule active. Many can exist; only one active.
• Why didn’t my rule fire on a Data Loader insert? — You must include the AssignmentRuleHeader in the API call, or set the option in Data Loader.
• Does Flow fire after assignment? — Yes, after the assignment is set as the Lead’s owner.

Verified against: Salesforce Help — Lead Assignment Rules. Last reviewed 2026-05-17 for Spring ‘26.