With the UK’s analogue phone network being retired, many business owners are comparing BT Digital Voice vs VoIP hosted phone systems and asking which is right for them. Both are digital, both run over broadband and both can keep your existing number. They are designed for different needs, though. This guide sets out the differences fairly so you can choose with confidence.
It’s written for owners and office managers of businesses with roughly 8 to 50 staff.
Why this decision is coming up now
The UK’s traditional telephone network, known as the PSTN, along with ISDN lines, is being retired. The deadline for the switch-off is 31 January 2027. After that, phone calls will run over digital, internet-based services instead of copper analogue lines.
Most businesses therefore need to move to some kind of digital phone service. For many, the two most obvious options are the digital landline service from their current provider, such as BT Digital Voice, or a hosted business phone system. Our PSTN switch-off page explains the wider changes.
What is BT Digital Voice?
BT Digital Voice is BT’s replacement for its traditional landline service. Instead of travelling over the old analogue network, calls are carried over a broadband connection. In most cases you keep your phone number and plug your phone into a compatible router rather than a wall socket.
For many homes and very small businesses, it’s a simple, familiar way to keep a landline working after the switch-off, often with very little change to how the phone is used day to day. BT also offers separate hosted business phone products for larger set-ups, which are a different service from a standard Digital Voice line.
Where BT Digital Voice works well
- Businesses that need one or two lines and want the phone to work much as it does now.
- Customers who want to stay with their existing provider and keep things simple.
- Sites where the phone is used occasionally rather than as the main customer channel.
What is a hosted phone system?
A hosted phone system, sometimes called hosted VoIP or a cloud PBX, is a complete business phone system run from a secure data centre. Rather than giving you a digital version of a single line, it gives every member of staff an extension, with features for routing, sharing and managing calls across the whole team. Our hosted PBX page explains how it works.
Staff can use desk phones, a desktop app or a mobile app, and everyone is on the same system wherever they work.
Where a hosted system works well
- Teams where several people answer and transfer calls.
- Businesses with more than one site, or with staff working from home.
- Firms that want call recording, reporting, queues or out-of-hours rules.
- Businesses replacing an older on-site phone system that relied on ISDN or analogue lines.
BT Digital Voice vs VoIP hosted systems: a side-by-side comparison
The table below compares the two in general terms. Exact features depend on the package you choose, so always check the details with any provider.
| Consideration | Digital landline (e.g. BT Digital Voice) | Hosted phone system |
|---|---|---|
| Main purpose | Replacing a traditional landline | A full phone system for a team |
| Keep your number | Usually yes | Usually yes, and number transfer to us is free |
| Extensions for each user | Not the main focus | Yes, one per user |
| Transfers between staff and sites | Limited | Yes, by extension number |
| Mobile and desktop apps | Depends on the package | Included |
| Call recording and reporting | Depends on the package | Included |
| Ring groups, queues and menus | Limited | Included |
| Best fit | One or two lines, simple use | Teams that rely on the phone |
Things to consider whichever option you choose
Your broadband connection
Both options rely on your internet connection. A reliable business broadband connection with enough capacity for the number of simultaneous calls you make is essential. If you have many users, it’s worth checking your connection and router before you switch.
Power cuts
Traditional copper landlines carried their own power, so a corded phone kept working in a power cut. Digital phone services rely on mains-powered equipment such as routers, so they won’t work in a power cut unless there’s a backup. If this matters to your business, ask your provider about battery backup options. With a hosted system, staff can also keep making calls on the mobile app over their mobile data.
Alarms, card machines and other equipment
Some alarms, lift lines, franking machines and older card terminals use analogue lines. Check each one with its supplier before the switch-off. Our guide on alarms and card machines after the switch-off covers this.
What about cost?
Prices vary by provider and package, so it isn’t helpful to compare a single line with a full team system on headline price alone. The more useful question is what you need the phone to do.
Our hosted business phone system is priced from £13.49 per user per month on yearly billing, or £14.99 per user per month on monthly billing. That covers a full extension for each user with features such as ring groups, call recording, reporting, voicemail to email and the mobile and desktop apps. As an example, a 10-user business would pay from about £134.90 a month on yearly billing.
Our business phone system cost guide explains the costs in more detail.
So which is right for you?
If you have one or two lines, use the phone occasionally and want minimal change, a digital landline service such as BT Digital Voice may suit you well.
If you have a team of 8 or more people who answer, transfer and share calls, work across sites or from home, or want recording and reporting, a hosted phone system is likely to be the better fit. It replaces both the lines and the phone system in one go.
If you’re not sure, we’re happy to look at how your business uses the phone and give you an honest view. Call 0333 307 3500 or request a quote.
Frequently asked questions
Is BT Digital Voice the same as VoIP?
Both carry calls over the internet rather than the old analogue network. BT Digital Voice is mainly a digital replacement for a landline, whereas a hosted VoIP phone system is a full phone system with extensions and features for a team.
Can I keep my number if I move to a hosted system?
In most cases, yes. Your existing number can usually be transferred, and we don’t charge for number transfer.
When is the PSTN switch-off?
The deadline for the switch-off of the traditional phone network in the UK is 31 January 2027.
Do I have to switch before the deadline?
Services that rely on the old network will stop working once it’s switched off, so it’s sensible to plan your move well before 31 January 2027 rather than leaving it to the last minute.