PSTN stands for Public Switched Telephone Network. It’s the analogue landline system that has carried UK phone calls for over a century. BT and Openreach are replacing it with digital phone lines that run over broadband, often called the digital switchover or the landline switch off. The date was originally December 2025. It was pushed back once, and Openreach has confirmed it won’t move again.

Most businesses have already switched without noticing. The ones that get caught out have older equipment nobody has checked for years. This guide explains what’s affected, what care providers need to watch for, and the five checks every London business should do now.

What stops working after the PSTN switch off?

It’s easy to assume you’re fine because your desk phones are new. The risk usually sits in the equipment you don’t think about. Any of these could still rely on an old analogue line:

• Phones at reception, even if they plug into a phone system rather than the wall socket
• Burglar and fire alarms that call a monitoring centre
• Card payment machines
• Lift emergency phones
• Door entry systems
• Fax machines and franking machines
• Older broadband lines that share the copper phone line

If one of these stops working on a Monday morning, you might not find out until a customer can’t pay or an alarm fails to call out.

What about my broadband?

Some older broadband connections share the same copper line as your phone. If your broadband is ADSL, or a fibre-to-the-cabinet service still tied to a phone line, your provider will need to move it too. Full fibre and newer “data only” lines aren’t affected.

This catches out a lot of offices in central London, where full fibre is still patchy. A business on an older line may find that digital calls drop or sound poor because the connection can’t keep up.

PSTN switch off for care providers: telecare and personal alarms

Care providers have the most at stake. Personal alarms and telecare devices help vulnerable people call for help, and many were built for analogue lines. The original switch-off date was delayed because of problems with exactly these devices during early migrations.

If you’re a home care agency or care home, ask yourself:

• Do any of the people you support use a pendant alarm or telecare service?
• Has the telecare provider confirmed in writing that the device works on a digital line?
• What happens to that device if the power goes off at the person’s home?

These questions also matter for your own office. If staff, families or commissioners can’t reach you, that’s a risk to the people in your care. Business continuity is also part of how CQC looks at whether a service is well led, so it’s worth having your answers written down.

PSTN switch off checklist: five things to check this week

1. Look at what’s plugged into your phone line. Phones, alarms and card machines might rely on it, even if they don’t plug straight into the wall.
2. Write down every number your clients call you on. Main line, direct lines, any old numbers still printed on letterheads or your website. Each one needs to move.
3. Ask your alarm company if they’re ready for the switch. Get the answer in writing.
4. Try a video call. If it keeps freezing, your broadband may struggle with digital phone calls too. This is common in parts of central London where full fibre isn’t available yet.
5. Find out if your phones still work in a power cut. Digital lines and on-site phone systems need power. A battery backup or calls diverted to mobiles keeps you reachable.

If you answered “not sure” to any of these, it’s worth getting someone to check.

PSTN switch off support in North West and Central London

Guard IQ helps care providers, law firms, accountants and other regulated businesses across North West London, Central London and Hertfordshire get ready for the PSTN switch off with as little disruption as possible.

• A switch-off check. We go through your office and list every device and number that relies on the old network.
• Broadband check. We test whether your connection can carry digital calls and tell you what your options are if full fibre isn’t available.
• Supplier coordination. We deal with your phone provider, alarm company and other suppliers so the right people move the right lines, in the right order.
• Power cut planning. We make sure you can still be reached if the power or internet goes down.
• A plan with dates. You get a written list of what moves, who moves it and when, well before 31 January.

Phones are only one part of your IT. Once the switch is done, we can look after your systems, security and compliance on a fixed monthly plan, so you have one person to call for all of it. Care providers can also see how we support Cyber Essentials certification and DSPT evidence.

PSTN switch off FAQs

When is the PSTN switch off?

The PSTN switch off date is 31 January 2027. Openreach has confirmed there will be no further delay.

Will my landline stop working on 1 February 2027?

Not all at once. Openreach plans a limited emergency calling service for lines that haven’t moved, but it’s a last resort and may not work for every line. Don’t rely on it to keep your business running.

Do I need a new phone system?

Not always. Many modern phone systems can connect to a digital line with a small change. Older on-site systems may need replacing or moving to a cloud phone service. A quick check will tell you which applies.

Will my burglar or fire alarm still work?

Only if it’s been tested on a digital line. Ask your alarm company to confirm in writing. Many older alarm diallers need an upgrade.

Will my card machine still work?

Most newer card machines use broadband or a mobile signal. Older machines that dial out over a phone line will stop working. Check with your payment provider.

What happens to my phones in a power cut?

Digital phones need power, so they stop in a power cut unless you have a battery backup. Diverting calls to mobiles is a simple fallback.

Will I keep my phone number?

Yes, in most cases. Your number can move to the new digital service. Make a list of every number you use so none get missed.

Does the PSTN switch off affect care homes and home care agencies?

Yes. Telecare devices and personal alarms are the highest-risk equipment. Check every device with your telecare provider before 31 January 2027.

Book a free PSTN switch off check

The closer it gets to 31 January 2027, the busier phone providers and engineers will be. If you’re a London business or care provider and you’re not sure where you stand, book a free 30-minute consultation at guardiq.co.uk/book. We’ll tell you what’s affected and what to do next.

Sources

• Openreach confirms post-January 2027 measures for the analogue switch-off, ISPreview
• Openreach says no big bang in January 2027, ISPreview
• Analogue switch-off delayed to 2027, ISPreview

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