The deadline for the UK’s analogue telephone network is 31 January 2027. After that date, Openreach will retire the Public Switched Telephone Network (PSTN) that has underpinned business phone lines in this country for generations, and every business still relying on it will need to have already moved to a digital alternative.
Most UK small businesses are aware something is changing. Far fewer have thought through what it actually means for them. The common assumption is that a provider will send a letter, an engineer will visit, a handset will be swapped, and that will be the end of it. For many businesses, that assumption will prove costly.
The PSTN switch off is not just a phone line issue. It is a business communications continuity issue, and some of the businesses most at risk are the ones that consider themselves least affected.
What is actually changing
The PSTN is the copper-based analogue infrastructure that carries traditional landline calls. For decades, it has also quietly supported a range of other business-critical systems that connect via that same telephone socket on the wall.
Under the digital switchover, voice services will move to VoIP (Voice over Internet Protocol), meaning calls are carried over an internet connection rather than a dedicated copper line. Ofcom has confirmed that small businesses wanting to keep landline services will need to move to VoIP before the deadline.
That shift sounds straightforward. The complication is that “anything plugged into an analogue wall socket just works” has been a safe assumption for so long that many businesses have never stopped to inventory everything that depends on it.
Why small businesses are more exposed than they realise
Larger organisations generally have IT functions that will be tracking infrastructure changes like this. Small businesses often do not. The owner, office manager, or operations lead may know the phones are working and reasonably assume that is sufficient. The PSTN switch off has a way of surfacing dependencies that have been invisible for years.
A few practical realities worth holding in mind:
Inbound calls are still revenue-critical for many small businesses. Missed calls mean missed enquiries, slower responses to existing customers, and a poorer overall service experience. A migration that goes wrong and leaves phones unreachable for even a short period has a direct commercial cost that is easy to underestimate in advance and difficult to recover from quickly.
Only 18% of small businesses currently have a post-PSTN solution in place. Research cited by Computer Weekly found that nearly one in ten small businesses are not yet aware the switch off is happening at all. That is a large proportion of businesses heading towards a hard deadline without a plan.
The hidden problem: it may not just be your phones
This is where the PSTN switch off catches businesses out. Ofcom has specifically highlighted that companies may have card payment machines, alarm systems, and monitoring equipment connected to landlines that will not work after the migration without replacement or reconfiguration.
These devices were set up at different times by different people, often without any particular thought given to their dependence on the analogue line. In many businesses, nobody has ever audited them together.
Common examples of line-dependent equipment that small businesses should check:
- Card payment terminals, particularly older models not yet upgraded to mobile or IP connectivity
- Intruder alarm systems with telephone-based monitoring or dialler units
- Fire alarm panels with line-connected signalling
- Door entry systems
- Lift emergency telephone lines
- Any legacy equipment using a fax line or analogue modem
None of these are guaranteed to continue working after January 2027 without action. A business that discovers this after the switch off has happened is dealing with the problem under pressure, without preparation time, and potentially in competition with every other late-migrating business for engineer availability.
The resilience question most businesses have not asked
There is a practical difference between analogue and digital voice that goes beyond the technology. Traditional landlines carry a small electrical current through the line itself, which means they continue working in a power cut. VoIP does not work this way. Digital phone services depend on an internet connection and on your router or switching equipment remaining powered.
For businesses where telephone availability during a power cut matters, a like-for-like migration is not enough. Depending on the setup, a backup arrangement may be needed: a mobile fallback number, a secondary device on a different network, or an uninterruptible power supply (UPS) to keep critical equipment running during an outage.
Most small businesses have never needed to consider this. After the digital switchover, some will need to.
Six questions worth asking before the deadline
If you are the person responsible for keeping your business running day to day, these are worth working through before time pressure forces your hand:
1. What in our business still relies on an analogue line?
Start with a physical check. Phones are the obvious answer, but think about every device that connects to a telephone wall socket, and every third-party service you pay for that may be using a line connection you do not directly manage.
2. Is our current phone setup fit for how the business actually works now?
Many businesses have changed significantly in recent years. Hybrid working, more mobile usage, different call volumes. A migration is also a chance to review whether your communications setup reflects current reality, not the one that existed when the system was first installed.
3. Which devices need replacing or reconfiguring?
Once you know what you have, you can find out what is compatible. Some equipment will need a simple configuration change. Some will need replacing entirely. That takes time and budget, and it is significantly easier to plan than to rush.
4. What happens to our phone capability in a power cut?
If staying reachable is important to your business, it is worth knowing the answer before the question becomes urgent.
5. Do we know when our area will be affected?
Openreach is running a phased programme across different exchange areas. Some areas will be migrated earlier than the national January 2027 deadline. It is worth checking when your area is scheduled.
6. Are we leaving this too late?
Providers across the UK are managing a national migration simultaneously. As the deadline approaches, capacity to support clean, well-managed transitions will tighten. Businesses that begin their review now have more options, more time to resolve complications, and more leverage in how their migration is managed.
The sensible response
The PSTN switch off does not require panic. It requires an audit.
Before January 2027, small businesses should take the time to map everything that currently relies on an analogue line, assess what will and will not work after the migration, and plan the transition in a way that protects their ability to stay operational and reachable. For most businesses, this is not a large project. But it does need someone to actually look, and it is considerably less disruptive to do that now than under a deadline.
The businesses that will feel this most are not the ones who planned early and migrated cleanly. They are the ones who assumed the phones were fine and discovered the gaps when the line went dark.
If you would like to review your current communications setup ahead of the digital switchover, 1Connect can help you understand your position, identify any hidden dependencies, and plan a migration that keeps disruption to a minimum. Get in touch to start the conversation.
Sources: Ofcom, Moving landline phones to digital technology: what you need to know; Openreach, Digital phone lines / All IP and Exchange Exit programmes; Zen Internet, The Great British Switch Off; Computer Weekly, UK businesses risk disruption as PSTN switch-off approaches.
