1. From the territory model hierarchy, open the territory where you want to create a rule.
2. On the detail page, in the Assignment Rules Defined in this Territory related list, click New.
3. Note If your org has enabled state and country picklists, territory assignment rules using states as a criteria must use contains matching instead ofequals matching.On the rule edit page, enter a name for the new rule and define selection criteria.
4. If you want the rule to also apply to the current territory’s descendents, select the Apply to child territories checkbox.
5. If you want the rule to run automatically when a user creates or updates an account, select the Active checkbox.Note For account updates, these conditions are required for the territory rules to run.If the account is updated via the UI, Evaluate this account againstterritory rules on save is selected.If the account is updated via API, AssignmentRuleHeader is specified.In Lightning Experience, the option to evaluate an account against territory rules when it’s updated and saved isn’t available. So active account assignment rules run automatically only if the update happens via API.
6. If the account is updated via the UI, Evaluate this account againstterritory rules on save is selected.
7. If the account is updated via API, AssignmentRuleHeader is specified.
8. Click Save to save the rule and return to the territory detail page.
9. (Optional) In the Assignment Rules Defined in This Territory related list, clickRun Rules. You’ll receive an email when the process is complete.