How your internet connection powers your phone
Guide reference: HG-0006
Quote this reference if you contact us about this guide.
Approx. 3 min read
Why your phone needs the router box to stay online. Your phone needs the router box and a working connection because digital calls travel through the line.
Don't worry if this sounds new. With a digital home phone, your calls share the same connection as your broadband through the router box.
Quick answer
Your phone needs the router box and a working connection because digital calls travel through the line. The router must stay connected at all times. Phone-only service still uses the box even if you never browse the web.
More detail
On an old copper line, the phone could work even when broadband was off. With a digital telephone line, phone and connection share the same router box.
You do not have to use the internet at home for browsing. Phone-only service uses only a tiny part of the line capacity, but the router still needs power and a working connection at all times.
The phone service is totally reliant on the internet feed. If the connection stops, your phone line stops too until it is fixed.
Personal alarms, security systems, payment devices, fax machines, and other equipment that relied on a copper line may not work on a digital line. Contact each provider to check before you order.
After rebooting the router, wait until the lights show ready before testing your phone. A power cut stops both unless you have backup power.
When you switch to us and keep your number, the phone line transfer does not move your old provider broadband. Cancel any old broadband separately after you have a go-live date from us.
Things to understand
The router or adapter box links your phone to your internet line.
Phone calls and internet data travel on the same connection.
If the box loses internet, you lose dial tone until it returns.
Rebooting the box can restore both phone and internet together.
Emergency 999 may not work in a power cut without backup power.
Common mistakes
- Testing the phone before the router has finished restarting.
- Assuming the phone should work when the internet light is red or off.
- Forgetting that a power cut affects both phone and internet.
Things to know
- See What router lights mean if both phone and internet stopped.
- See Emergency calls during a power cut for 999 in a power cut.
- See Why you need a router for your phone for what the box does.
- If you use your own broadband with our telephone adapter, See Digital home phone with your own broadband instead of a router we supply.
Frequently asked questions
Does slow internet mean bad phone calls?
Sometimes. Poor connection can affect call quality. See Slow internet
Can I use the phone without browsing the web?
Yes. Phone-only service is available, but the box still needs a working connection.
What if only the phone fails?
Try no dial tone steps first. The box may need a restart.
Does my old broadband move with the phone line?
No. Call your old provider to cancel broadband after you have a go-live date from us.