Types of Area Code Changes

The Overlay Method
The Overlay Method is another way of making additional phone numbers available. It places a new area code "on top of" an existing one. Both area codes serve the same location. New phone numbers get the new area code. Existing numbers do not have to change.

In areas where an overlay has been implemented, 10 digit dialing must be used, but there is no change in the way calls for 911 emergency service or 411 directory assistance are placed. What was previously a local call will remain a local call regardless of the number of digits dialed.