If AutoFill won’t work

You may have AutoFill turned off. To turn it on, choose Safari > Preferences and click the AutoFill tab. For more information about the AutoFill options, click the Help (question mark) button.

Safari may not be able to find a match. For instance, Safari uses the information on your address book card to autofill forms. If a form requires your phone number but it’s not on your card, you’ll have to fill it in manually.

You may not have permission to use your own address book.