If you haven’t heard yet, BT is switching off the UK’s traditional copper phone network — known as PSTN and ISDN — in January 2027. That means every business in the country that still relies on a landline will need to move to a different solution before that deadline arrives. For most businesses, that solution is VoIP.
But switching phone systems is a big decision. Is VoIP really better than what you’ve got now? Will it work reliably? And what does the switch actually involve? In this post we’ll answer all of that — plainly and honestly.
What is VoIP?
VoIP stands for Voice over Internet Protocol. In plain English, it means making phone calls over the internet rather than through the old copper wire network. Instead of your voice travelling down a physical telephone line, it’s converted into digital data and sent over your broadband connection — just like an email or a video call.
You don’t necessarily need special phones to use VoIP. Many systems work with desk phones that look exactly like traditional ones, with handsets and buttons. Others work through a softphone app on your computer or mobile, so your staff can make and receive calls from anywhere. Some systems offer both.
VoIP isn’t new — large businesses have been using it for years. What has changed is that it’s now affordable, reliable, and genuinely easy to set up for smaller businesses too. The technology has matured considerably, and the quality of calls today is generally better than what you get on an old analogue line.
What’s Happening to Traditional Phone Lines?
The UK’s traditional phone network — PSTN (Public Switched Telephone Network) and its business-focused sibling ISDN (Integrated Services Digital Network) — was built on copper wires laid decades ago. BT’s Openreach has been maintaining this infrastructure for years, but the technology is ageing and increasingly expensive to run. The decision has been made to switch it all off.
The original switch-off deadline was December 2025, but BT pushed it back to January 2027 to give businesses more time to prepare. That might sound like a long way off, but it isn’t — particularly if you’re mid-contract on an ISDN line, or if your phone system is tied to other infrastructure like door entry, alarm systems, or card payment terminals. All of these may also need updating.
After the switch-off date, analogue landlines simply won’t work. If you haven’t migrated to a digital alternative by then, your business phones will go dead. The sooner you start planning, the more control you have over the timing and cost of the transition.
VoIP vs Traditional — A Comparison
| Feature | Traditional Phone (PSTN/ISDN) | VoIP |
|---|---|---|
| Cost | Higher line rental and call costs; expensive to scale | Lower monthly costs; free or very cheap internal calls |
| Features | Basic — hold, transfer, voicemail | Advanced — call recording, hunt groups, auto-attendant, call analytics, mobile apps |
| Flexibility | Fixed to a physical location; adding lines is slow and costly | Add or remove users instantly; staff can work from anywhere |
| Reliability | Very reliable unless line is physically damaged | Reliable on a good broadband connection; failover options available |
| Installation | Requires physical line installation; longer lead times | Typically configured remotely in hours; minimal disruption |
| Future-proof | No — being switched off in 2027 | Yes — the direction the entire industry is moving |
Who Should Switch to VoIP?
The honest answer is: almost every business. The 2027 switch-off means you’ll need to move eventually regardless — but beyond that, VoIP genuinely is a better product for most business use cases.
It’s particularly well-suited to:
- Remote and hybrid teams — staff can use their work number on a mobile app or laptop from home, a client site, or anywhere with an internet connection. To the caller, it looks like they’re at the office.
- Multi-site businesses — a single phone system can cover multiple locations, making internal calls free and giving customers one central number regardless of which site they reach.
- Growing businesses — adding a new team member to a VoIP system takes minutes and costs a fraction of what adding a traditional line would. You scale up (or down) without waiting weeks for an engineer visit.
- Businesses that want better features — auto-attendants, call queuing, call recording, voicemail to email, and detailed call reports are standard on most VoIP platforms and would cost significantly more on a traditional system.
What About Reliability — What if the Internet Goes Down?
This is the most common concern we hear, and it’s a fair one. VoIP does depend on your internet connection, so if your broadband fails, your phones could go with it. But there are straightforward ways to protect against this.
Most VoIP systems allow you to configure failover routing — so if your main internet connection drops, incoming calls are automatically diverted to a mobile number or an alternative site. Your customers won’t know anything has changed.
For businesses where phone availability is critical, we often recommend a 4G or 5G backup router. This sits dormant until your main connection fails, then kicks in automatically — keeping your internet (and therefore your phones) running until the primary line is restored. When you factor in a modern broadband connection alongside a 4G backup, the overall resilience of a well-configured VoIP system is very high.
How to Make the Switch
Switching to VoIP doesn’t have to be complicated. Here’s how the process typically works:
- Step 1 — Review your current setup. We’ll check what lines and equipment you currently have, identify any connected systems (alarms, card machines, door entry) that might also be affected, and map out what needs replacing.
- Step 2 — Choose the right VoIP solution. Not all VoIP platforms are the same. We’ll recommend one that fits your team size, working patterns, and budget — whether that’s a hosted system with desk phones, a fully mobile setup, or a hybrid of both.
- Step 3 — Number porting. You keep your existing phone number. We handle the porting process, which transfers your current number to the new VoIP system. This is usually seamless and your number won’t go offline during the transfer.
- Step 4 — Installation and training. We configure the system, set up all your users, and make sure everything works before your old line is cancelled. We’ll also walk your team through how to use the new system — it’s usually much simpler than people expect.
The Bottom Line
VoIP is not just a replacement for traditional phones — it’s genuinely a step forward. Better features, lower costs, more flexibility, and a system that works wherever your staff are. The 2027 PSTN switch-off means the question is no longer whether to move, but when.
The businesses that switch early get the most benefit — lower bills sooner, more features sooner, and no last-minute scramble as the deadline approaches. If you’re still on a traditional line, there’s never been a better time to make the move.
Find out more about our VoIP telephony services, or get in touch and we’ll give you a straight answer about what’s right for your business.