About smart dialing
You can change smart-dialing options to specify a default country code and area code for phone numbers. If you specify a default country code and area code, when you make calls, you only need to dial a country code and area code when the codes differ from the codes that you specified in the smart-dialing options.
Depending on your BlackBerry® device model, in the smart-dialing options, you can also specify the main phone number for an organization that you call frequently. If you specify a phone number for an organization, you can call a contact at the organization quickly by dialing the contact's extension only. Likewise, when you add a contact from the organization to your contact list, you only need to type the contact's extension.