By default it is not enable, so admin need to activate it manually, although it is pretty easy. The setup is buried deep inside Setup menu. Here we go: Setup - Customize - Search - Search Settings. Scroll down to Lookup Settings and look for objects that you need enable for auto-completion then check Lookup Auto-Completion for the objects.
Few items to note for Auto-Completion in Salesforce:
- Admin have to manually enable objects for auto-completion. So, when a lookup field created, the parent object (not child object) need to enable for auto-lookup.
- Same as other area in Salesforce, it is case-insensitive
- It only work for both Master-Detail and Lookup relationship, not for text field or other.
- It displays suggestions from My Recent Items list as you type, but recent items here is not limited to the items in side bar, but including in recent tab and list view.
- It will catch character in a word start with, so for example: when you type ed, it will catch Kia Edan and edwin, but not medan.
Here a screenshot before turn on auto completion, when user type in Customer Id field, nothing show up:
After turn it on, when user type a character it will show recent record from parent object.