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Information Systems Department

Change to local phone dialing

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Mandatory 10-Digit Dialing Becomes Effective on October 24, 2021 for Multiple States/Area Codes. 

What is happening? 

Beginning October 24, mandatory 10-digit dialing (area code + telephone number) is being implemented for all local calls.


Who will be affected?

This change affects all employees and all calls originating from the 707 area code.


Why is this happening? 

The Federal Communications Commission (FCC) has adopted 988 as a new three-digit number to be used nationwide to reach the National Suicide Prevention and Mental Health Crisis Lifeline. Area codes that use 988 as a local exchange, or the first three digits of a seven-digit phone number, will need to use 10-digit dialing. This includes the 707 area code. For more information, see this FCC site.


What’s the rollout plan? 

This change becomes effective on October 24.


What does this mean for users? 

Since ISD will be modifying dialing rules so that all outbound numbers will prepend 707 to any 7 digit numbers that are dialed, most users won't need to change their day-to-day process.However, some users may manage a device that will be impacted – more on that below.


What do I need to do? 

If calling from a county desk phone, it is not necessary to use the full 10-digit number; the county system will automatically add the area code to complete the call. Additionally, dialing by four-digit extension will not be affected by this change.


If calling from a personal device such as a home phone or personal cell phone, you will need to dial the full area code and telephone number to make a local call.


If you are an employee that manages any automatic dialing equipment such as fax machines, emergency “red” phones, fire or burglar alarms, security systems or gates, phone contact lists, services that notify via SMS, etc. you should check to see if the system needs to be updated to work with the new 10-digit local dialing rules. A good indicator as to whether a system should be updated (or at the very least checked) is if the number starts with a prefix other than 565.


Is anything different if I’m working remotely? 

This change affects all calls made locally, whether remote or on the County campus. 


Is there anything else I need to know? 

The Global Address Book (GAL) will be adjusted to include the full area code and number prior to the change. 



Please send an email to or call us at (707) 565-2030.