Technology is evolving at an astonishing rate, and that brings both opportunities and challenges. One such change is the permanent shutdown of the Public Switched Telephone Network (PSTN) by BT.
“What exactly is PSTN, and why should I care?” you might ask. Put simply, PSTN is the backbone of traditional landline telecommunications, the grandparent of modern communication technology. PSTN relies on analogue technology and a physical network of copper cables to transmit sound. Remember picking up a receiver and hearing that familiar dial tone? That’s the world of PSTN.
The impending shutdown means you’ll need to make significant changes to how your business communicates, and the clock is ticking. UK businesses that continue to rely on PSTN will lose the ability to make and receive calls, communicate via fax, and could even see their internet access compromised. If your business still uses PSTN, you’ll need to switch services as soon as possible or risk losing business continuity.
How do I know if I’m using PSTN?
Before transitioning to alternative services, it’s worth knowing that PSTN (Public Switched Telephone Network) isn’t confined to traditional phone systems. Door-entry systems, CCTV networks, fax machines, PSTN alarm systems and even EPOS systems can rely on it, though here we’ll focus on telephony.
Understanding your current setup is crucial, because it informs your transition plan. Here are some pointers to identify whether your business relies on PSTN:
- Analogue phones, traditional analogue handsets connected to phone jacks using landline numbers.
- Fax machines, if you rely on a traditional fax machine, PSTN is involved.
- ISDN services. Integrated Services Digital Network lines are often associated with PSTN.
- DSL internet. DSL broadband often shares the same physical infrastructure as PSTN.
- Dial-up modems, a clear indication of PSTN usage.
- Traditional phone bills, charges for traditional phone lines suggest PSTN is in use.
- Consult your provider, they can confirm exactly what technology you’re on.
I’m using PSTN, what do I do?
As the PSTN switch-off moves into a critical phase with ‘stop sell’ regulations being enforced across the UK, discontinuing PSTN isn’t just about saying goodbye to outdated technology, it’s about ensuring your business keeps communicating. To prevent disruption, move to digital telecommunication as soon as possible. Our top recommendation at Sereno is to switch to Business VoIP without delay.
VoIP (Voice over Internet Protocol) is a form of digital communication that lets you make voice calls over a broadband internet connection rather than traditional phone lines. You’re no longer bound by the limitations of landlines, it opens up a world of possibilities for your business communications.
Why business VoIP?
Internet calls, video conferencing, and online collaborative tools have far exceeded the capabilities of PSTN, and it is becoming increasingly difficult to maintain. By the end of 2025 PSTN will be switched off across the United Kingdom, ushering in a new era of telecoms.
Editor’s note: BT have since rescheduled the PSTN switch-off to January 2027.
BT put it perfectly. With the deadline on the horizon, it makes sense for UK businesses to make the switch to business VoIP now, making the transition smoother and avoiding a last-minute rush as the shutdown date draws nearer.
More importantly, VoIP is a superior and more affordable alternative to traditional landlines. It offers enhanced capabilities, seamless scalability and better cost-efficiency, and it’s built for the modern way of working, enabling easy hybrid working wherever your team is located.
VoIP vs PSTN, how do they compare?
VoIP is generally more flexible, affordable and efficient than PSTN, which is why so many UK businesses already favour it. Here’s how they stack up:
How does business VoIP work?
Because VoIP uses the internet to connect, employees can make calls from a computer, a specialised VoIP phone, or a traditional phone connected to a special adapter. Calling through a computer means staff can log on and get started straight away with no extra device, perfect for those who work between home and the office. Calls can also be made on the move via wireless hotspots and 4G/5G.
If you switch, you’ll first choose a VoIP provider and a plan that suits your business, i.e. how many users will be making calls (we can help with this!). You’ll then get the necessary hardware and software (VoIP phones and servers), and your provider sets up and maintains your VoIP system for you.
Ready to switch to business VoIP? Here’s what you need to know
You’ve heard why PSTN is shutting down and why VoIP is the better option. Before you switch, here’s what to consider before, during and after the migration:
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Before, prepare for the switch
Check your internet line has enough bandwidth for the volume of calls you make (the minimum per call is tiny, so most providers cope easily, but it’s worth confirming). Best practice is to run VoIP on a secondary internet line, so you have a backup if one line goes down; some providers offer a cheaper ‘Assured IP line’ just for telephony. Confirm your existing handsets are VoIP-compatible (many traditional phones aren’t), decide whether you want desktop or mobile apps, and think about the features you’d use, menu systems, voicemail, call recording, call stats and reporting.
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During, make the move
Your VoIP provider and/or IT partner supports you throughout, testing the new system by running it alongside the old one on separate numbers before porting your main numbers over. We advise you request free demos of cloud-based VoIP systems and test them, and clearly document your telecoms process (menu systems, hunt groups, call trip-overs, direct dials). Note that porting a number can take a while, get a clear timeline from your provider.
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After, bed it in
Keep testing and ask staff to record any problems, then re-document any changes to your system setup and call flow.
Switch to business VoIP with Sereno IT
The easiest way to choose from UK VoIP providers is with the support of your IT partner. At Sereno, we’ll help you scope out the right provider and plan, acting as your single point of contact so all your technical support is under one roof. With Sereno you’ll benefit from:
- The support service you expect, with consistent, agreed SLAs in line with the rest of your IT support
- A dedicated team of IT experts who liaise with your VoIP provider for you, so you’re never stuck in the middle
- Confidence that the network infrastructure VoIP relies on is already managed by us
- Help with the installation process, set up in a reliable way that’s easy for us to support
- Transparent advice about the best VoIP providers and plans for your business
- More competitive pricing, thanks to our long-standing, trusted relationships with world-class suppliers
For more information, contact us today and speak to one of our friendly team about how Sereno can help you switch to business VoIP.
Written by
Sahaj Arrora
Part of the Sereno IT team helping growing UK businesses make confident, jargon-free technology decisions. Read more connectivity & communications guidance in our Connectivity & Communications library.
