Use Prefix Dialer to automatically add a default prefix to your calls. This is often helpful when making International calls. Siri functionality included: ask Siri to call your contacts using Prefix Dialer.
Example:
If a contact has the number 800-888-8888, Prefix Dialer will inset the prefix and default county code before the number. If the prefix is 014, and the country code is 1, it will call 014-1-800-888-8888