What does a VoIP phone system actually mean?

A phone system that sends calls over the internet rather than a dedicated phone line. It still connects to every normal mobile and landline.

Is VoIP the same as Wi-Fi calling?

Wi-Fi calling is your mobile network routing your personal number over Wi-Fi. VoIP with Line is your business number working over any connection, with routing and a team inbox behind it.

Does VoIP work on a mobile phone?

Yes. The Line app makes and takes VoIP calls over Wi-Fi or mobile data, just like any other call.

Does VoIP work without the internet?

No. If your phone has no data, calls follow your fallback rule. In practice, mobile data covers the gaps in Wi-Fi.

Can I use my current business number?

Yes. Port any eligible UK number to Line. Keep the old service until the port completes.

How is VoIP different from a cloud phone system?

VoIP is the transport. A cloud phone system is the whole service around it: numbers, routing, voicemail, team, inbox. Line is a cloud phone system that uses VoIP.

VoIP phone system

Business calls over the internet, from any phone you own

VoIP carries your calls over Wi-Fi or mobile data instead of a copper line. Line adds the business number, the routing, and the shared history on top, in an app that runs on the phones you already carry.

Get your business number See pricing

From £4 a month. Pay only for the calls and texts you use. No minimum term.

MEMason Electrical07700 900222 · VoIP

Incoming call · office Wi-FiAnswered on the laptop
Morning, it's the site manager at Elm Road. Can you come by at two?
Yes, I'll be there at two.
Jo · from the laptop
Outbound call · 4G in the vanSame number, 45 minutes later
Call · 2 min
Logged to the Elm Road thread with the transcript.

What is VoIP?: Voice over Internet Protocol. Your call travels over the internet instead of a traditional phone line. The person you're calling notices nothing.
Can I call normal phone numbers?: Yes. VoIP calls reach any UK mobile or landline. The other person doesn't need VoIP or an app.
What connection do I need?: Any decent internet connection. Wi-Fi, broadband, or 4G and 5G mobile data all work.

The call follows you, not the wall socket

The same business number rings whichever devices you choose, wherever they are.

Answer on whatever's in front of you

Laptop at the desk, mobile in the van. The number and the history are the same on both.

Route before it rings

Hours, ring groups, voicemail, missed-call texts, and Molly all sit in front of the call.

Calls next to texts

Every call is logged in the same thread as the customer's messages. No separate call log to check.

Set up in an afternoon

No engineer, no hardware, no contract. Three steps from sign-up to your first call.

1
Check your connection
Make a test call on the Wi-Fi and the mobile network you actually use during the day.
2
Add your number
Pick a new UK number or port the one customers already call.
3
Test the edge cases
Inbound, outbound, no answer, out of hours, and caller ID. Then tell your customers.

What makes a VoIP call work

Good connection, good routing. Line handles the second part for you.

When this happens	Line does this	So you get
Solid Wi-Fi or 4G	The app rings and carries the call over the live connection.	Clear audio on the device you're holding.
You're busy or offline	The call moves to the next step instead of ringing forever.	A teammate, voicemail, a text, or Molly picks it up.
You call a customer back	The call goes out via Line with your business caller ID.	Customers see the number they know.

Worth knowing

The old landline network switches off in January 2027

Openreach is retiring the analogue phone network on 31 January 2027. A business still on a traditional landline needs a digital replacement before then. Moving early means you choose the timing, not your provider.

Source: Ofcom, Your landline is going digital

Most UK phone lines are already internet-based

Ofcom counted 1.9 million lines moving from the old network to VoIP in the twelve months to July 2025. Internet calling is now the normal way a business phone works, not the new one.

Source: Ofcom, Connected Nations UK 2025

Questions people ask

Straight answers on setup, limits, and what it costs.

Cloud phone system

The whole service around the call.

Business voice calls

Calling, transcripts, routing, and voicemail.

PSTN switch-off guide

Get ready for the UK move to digital voice.

Last reviewed 6 September 2026. Sources: Ofcom, Your landline is going digital, Ofcom, Connected Nations UK 2025.

Never miss another customer

Pick a UK number, add your team, and choose what happens when you can't answer. Live in minutes, on the phone already in your pocket.

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