4. Split versus Overlay

A split allows some existing customers to retain their current telephone numbers while others will not. Those customers whose numbers change will incur the inconvenience of having to notify family, friends and those they do business with of the change. In the case of some businesses, they will also incur costs for new business cards, stationary, etc., and may lose business because existing or potential customers are not made aware of the change. All customers will have to dial 1 plus the area code and the new phone number (1+10 digit dialing) to reach customers who are on the opposite side of the geographic demarcation between the 818 area code and the new area code.

An overlay requires no customers to change their numbers. However, they will have to use 1+10 digit dialing for all calls.