Change Internet Provider or Router Without Losing Phone Service

Plan the cutover before disconnecting the old network

Changing an internet provider, router, firewall or office network can interrupt desk phones and browser calling. Arrange the change with your IT team and Zonitel before installation day, especially if phones use a managed network or fixed network settings.

1. Send the change details in advance

• Business/location and main telephone number.
• Installation date, time zone and expected interruption window.
• Old and new internet providers, and whether the router, firewall, switches or cabling will change.
• Phone models, affected extensions and an on-site contact for the installation.
• Any known fixed IP addresses, dedicated phone network or other special setup. Ask IT to confirm these details instead of guessing.

Changing internet service is different from porting a telephone number. Ask both providers about any bundled or dependent services before canceling the old account.

2. Record the working setup

In Office, open Settings → Extensions for the correct location and identify the extensions you need to test. Note the intended outbound numbers and who should receive incoming calls. Review the active number route under Settings → Phone Numbers → Call Flow.

The list's Enabled setting and Show in Active Calls switch do not prove that a phone is connected or ready to receive calls. Check the physical phone or browser phone and make a baseline call before the network change.

3. Coordinate network work with IT

• Confirm how each phone gets network access and power, including Ethernet and any switch providing power.
• Ask IT whether phones receive addresses automatically or have fixed settings that must be updated for the new network.
• Have IT and Zonitel review any firewall or provider-specific requirements for your setup. There is no universal IP address to enter into every phone.
• Arrange a fallback contact method and a rollback plan with the installation team. If temporary forwarding is needed, confirm the exact destination and how to restore the normal route afterward.

Do not factory-reset the phones or copy credentials into unfamiliar router fields. Do not disable firewall protections, expose phones to the internet or change provisioning settings as a shortcut. Ask the responsible team to make the required, specific adjustments.

4. Run a short acceptance test

1. Check that each affected phone has power, a network connection and the expected extension without a service error.
2. Test a direct extension call where applicable.
3. Call the main business number from an external phone and follow its normal route to a team member.
4. Make an authorized outgoing call. Confirm the displayed business number and audio in both directions.
5. Test unanswered-call routing, voicemail and a transfer or other essential call-flow step used by your team.
6. For browser calling, check the phone tab, microphone/speaker selection and permissions on the new connection.

If a test fails

Tell support which extensions are affected, what the phone screen says, the network change time and a recent failed call's calling number, called number, time and time zone. State whether the problem affects one phone or the whole office, incoming/outgoing calls or audio. A working website on a computer is not a complete phone-service test.

Before canceling the old connection or leaving the site, confirm results with the installation team. If you used temporary forwarding, restore and test the intended final route with the responsible administrator.

Related guides

• Desk phone not ringing or showing No Service
• Make and receive calls from your browser

Need help?

Call, text or WhatsApp (833) 966-4835, or email info@zonitel.com. Share relevant examples privately; never include passwords or verification codes.