The 909 is running out of phone numbers.The California Public Utilities Commission is aiming to introduce a new area code to the region served by the 909 — which includes cities from Walnut … ...

1: Callers with 909 area codes must dial 1 ahead of the area code and telephone number for all calls. 2: Calls that do not follow the new dialing procedure will not be completed, CPUC officials say.

A new area code could soon be added to cities served by the 909. That has local businesses worried about what that means for their existing numbers and advertising.

The 11-digit dialing process will be mandatory starting Jan. 23 for all customers with a telephone number in the 909 area code.

The number crunch is prompting the commission is introducing a new area code to the 909 territory, she said.

Here is what you need to know about the addition of a new area code: • Existing numbers with a 909 area code will not change — this includes landline and mobile phones.