SIP Trunks for UK Business

For your existing phone system

Keep your phone system. Lose the old phone lines.

If your business already has an on-site phone system, SIP trunks connect it to our network over your internet connection, replacing ISDN and analogue lines as the UK moves away from traditional phone lines.

You keep your phone system, your extensions and your numbers, while benefiting from lower call costs, flexible capacity and support from our own UK team.

Keep your numbers

Move your existing numbers across.

Flexible channels

Add capacity as you grow.

Built-in resilience

Re-route calls if your site goes offline.

Lower call costs

No line rental for old phone lines.

Still on ISDN or analogue lines?

Traditional phone lines are being switched off across the UK. We can move you to SIP trunks, or to a cloud phone system, with no disruption to your calls.

Talk to us

How it works

Switching to SIP in four steps

1
Review your set-up
We check your phone system, numbers and call volumes.
2
Size your trunk
We recommend the right number of channels and quote.
3
Connect and test
We configure the trunk and test calls before switching.
4
Move your numbers
Your numbers move across with no interruption to calls.

SIP trunks or cloud phone system?

Two ways to move your calls online

SIP trunks

Best if you have a phone system you want to keep. We connect it to our network and you continue to manage it as you do today.

Get a SIP quote

Cloud phone system

Best if you would rather not run a phone system at all. We host everything, from £4.99 per user a month.

Explore the cloud phone system

FAQ

SIP trunk questions

What is a SIP trunk?

A SIP trunk connects your own phone system (PBX) to the telephone network over an internet connection instead of traditional ISDN or analogue lines. Each "channel" carries one call at a time.

Will it work with my phone system?

SIP trunks work with most modern IP phone systems. Tell us your make and model and we will confirm compatibility before you switch.

Can I keep my numbers?

Yes. We can move your existing numbers onto your SIP trunk, and add new local, London, 03 or freephone numbers at any time.

How many channels do I need?

One channel for each call you want to make or receive at the same time. We will help you size it from your current call volumes, and you can add channels as you grow.

What happens if my office connection goes down?

Calls can be re-routed automatically to mobiles or another site, so customers can still reach you.

Should I choose SIP trunks or a cloud phone system?

If you have a phone system you want to keep, SIP trunks connect it to our network. If you would rather not run a phone system at all, our cloud phone system replaces it entirely.

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