Require Users to Assign an ID When Creating New Customer Records

When users do not want to use Auto-Generated Numbers and instead want to manually enter a value for Customer ID field when creating new customers, the following steps must be done:

1. Navigate to Setup > Company > General Preferences.
2. Locate the Auto Name Customers checkbox and uncheck it.
3. Click Save.
4. Navigate to Setup > Company > Auto-Generated Numbers.
5. Under Entities tab, uncheck the Enable checkbox for Customer.
6. Click Save.