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E-911

Enhanced 911 services

Enhanced 911 Program Office 
7300 Perimeter Rd S, Room 128
Seattle, WA 98108-3848
206-296-3910
Fax: 206-296-3909

King County
Office of Emergency Management

3511 NE 2nd Street
Renton, WA 98056-4192
206-296-3830
Fax: 206-205-4056
OEM home page

9-1-1 and VoIP Phones

Many people are giving up their traditional wireline phone service at home and moving to Interconnected Voice over Internet Protocol (VoIP) phone service.  Interconnected VoIP service allows you to make and receive calls to and from traditional phone numbers using an Internet connection, such as Digital Subscriber Line (DSL), cable modem, or wireless broadband.  Some of the providers of VoIP service in King County are Comcast, Vonage, and CenturyLink.  People may not even realize that they no longer have wireline phone service, because providers may simply call it “home phone service”.  VoIP phone service is attractive because it may be bundled with internet and TV for one price, and may offer free nationwide calling.

 People should be aware that VoIP 9-1-1 service works differently than traditional wireline 9‑1-1 service.

  • Caller address information may not display correctly at the 9-1-1 Center for VoIP 9-1-1 calls. With wireline phones, each address that is added to the 9-1-1 database is checked to make sure it fits with countywide addressing standards.  With VoIP, the 9-1-1 Office is unable to see what addresses people provided for their phone until they call 9-1-1.  If the address is incorrect, they must be able to provide their correct address before help can be sent.
  • A VoIP 9-1-1 call may not go to the correct 9-1-1 center. If someone has provided an incorrect address for their phone, their 9-1-1 call could route to the wrong 9-1-1 center, causing the emergency response to be delayed while the correct address is determined and the call is transferred to the correct center.  When the VoIP phone service can be moved to different locations and the owner doesn’t update the address, the 9-1-1 call can even be routed to the wrong state or country.
  • VoIP phone service requires power, and may not work during a power outage.  The battery on a VoIP phone may only last up to four hours, and then the phone will no longer work.  During winter storms or disasters when people may need help, their phone may not work to call 9-1-1.
  • The VoIP phone may not be capable of placing a 9-1-1 call.  Some VoIP services cannot call 9-1-1.  The caller may receive a "service not available" recording.  Programming a ten-digit number for a 9-1-1 center into the phone DOES NOT provide 9-1-1 service.  Your call will be answered at a lower priority than 9-1-1 calls, and no information is provided, so you must be able to give your phone number and location before help can be sent.
  • A VoIP phone WILL LOOK LIKE ANY OTHER TELEPHONE. Even if the phone's owner understands the 9-1-1 issue, visitors or others will expect the phone to provide them with access to Enhanced 9-1-1 service when they call 9-1-1 in an emergency.  

Read the fine print
Before you sign up for a VoIP Phone, King County 9-1-1 encourage you to read all 9-1-1 information so you clearly understand the 9-1-1 capabilities of VoIP phone service.

When considering switching from traditional wireline phone service to VoIP phone service, be an informed consumer. Anyone who is thinking about switching to VoIP phone service needs to read the fine print and realize that the 9-1-1 service they have come to rely on may not work the same for this new phone service.

For information on FCC regulations and challenges of VoIP phones please visit the FCC website.
For further questions about VoIP phones contact Marlys Davis, E-911 Program Manager.


Please use 9-1-1 responsibly. Call only if you need an emergency response from police, fire or medics. For non-emergencies call your local police or fire department or other appropriate agency.