Our friend over on the Android blog have a recent post regarding adding a prefix to a call.
At St. Thomas, the global directory generally includes only the extension. And as such, you cannot simply call a number after searching the directory with the Contacts app on your iPhone. Luckily, there’s an app for that (a few actually) and they are free!
The one that appears best for our use is called PrefixACall.
As the name suggests, PrefixACall adds the prefix you defined when you call a number selected from your iphone address book. It also has a Favorites tab which enables you to easily add prefix to frequently called numbers.
When you first launch the app, you’ll ned to setup the prefix to use. (65196) Then, you can search for contacts by tapping on the Contacts tab. If your phone is connected to Exchange (if it isn’t, it really should be!) you can tap the Groups button in the top left of the screen and then choose St/ Thomas Global Address List from the bottom of the view. Then, just search for your contact and, if they have a phone number listed in the directory, tap that number. The prefix will be applied and the call will be made with the standard Phone app.