By default Outlook sorts your contacts by FirstName, LastName. You can reverse this if you want to have the contacts sorted by last name instead by using the steps outlined below:

1. Open Microsoft Outlook.

2. From the Tools menu, click E-mail Accounts.
3. Click View or change existing directories or address books.
4. Click Outlook Address Book and click Change.
5. Under the list of Outlook Address Books, select the one you want to change the sort order for.
6. Click File As (Smith, John).
7. Click Close.
8. Click Finish.

Exit Outlook to have your changes applied. Once you re-open Outlook, you can verify that the sort order has been changed to last name. From the Tools menu, click Options. From the Preferences tab, click the Contact options button. Verify that Last, First is listed as the Default “File As” order.