The PSTN & ISDN Switch-Off: What It Means for Your Business
The UK's old phone network is being switched off on 31 January 2027. Here's what changes, what to check, and how to move across without disruption.
What is happening?
Openreach is retiring the UK's traditional phone network, the PSTN (the analogue phone network) and ISDN (older digital business lines), on 31 January 2027. After that date, phone lines and services that run over the old copper network stop working. Anything that relies on a traditional phone line needs to move to a digital, internet-based alternative before then.
This is not optional and there is no extension. The good news is that the replacement technology is better, with clearer calls, more features and usually lower running costs, and with the right plan the switch is straightforward.
It's not just your desk phones
Plenty of everyday business equipment quietly runs over a phone line. Any of these can stop working at switch-off if they are not moved across:
Phone systems
Analogue and ISDN phone lines, on-site PBX systems and the handsets connected to them.
Alarms & security
Monitored intruder and fire alarms, and some CCTV, that dial out over a phone line.
Lift & emergency lines
Lift autodiallers and emergency help points that must stay connected by law.
Door entry
Door entry and gate intercoms that call out over an analogue line.
Card machines
Older PDQ / card payment terminals that dial for authorisation.
Fax & other lines
Fax machines, franking machines and any other device on a dedicated line.
The business owner's switch-off checklist
- Find your lines. List every phone number and line you pay for, including ones you rarely think about (alarm, lift, lobby, fax).
- Find what's attached. For each line, note what uses it: phones, alarm, lift, card machine, door entry.
- Check your contracts. Note renewal dates and notice periods on your current phone and line contracts so you switch at the right time.
- Choose your replacement. Most businesses move to hosted/VoIP phones and, where needed, a digital line for alarms and lifts.
- Plan the cutover. Keep your existing numbers, test everything, and switch with no downtime.
- Don't leave it to the deadline. Lines are being switched off in stages now, so earlier is calmer and cheaper.
Not sure where to start? That's exactly what our free line audit is for, and we do the first two steps for you.
How much time do you have?
Now – 2026: Openreach is already stopping new traditional line orders and switching areas over in stages. Many businesses are moving now to avoid the rush.
31 January 2027: the PSTN and ISDN network is switched off for good. Services still running on it stop working.
Moving early means you pick your timing, test properly, and avoid being in the last-minute queue as the deadline approaches.
A calm, managed move with Parkway Telecoms
We're owner-managed and local, and we move businesses off the old network every week. We'll audit your lines, tell you plainly what needs to change, keep your existing numbers, and handle the cutover so your phones and critical lines keep working throughout.
We replace old phone systems with hosted phone systems and, where you need them, modern business connectivity and digital lines for alarms, lifts and card machines.
Frequently asked questions
Q: When exactly is the PSTN switch-off?
The UK PSTN and ISDN network is being switched off on 31 January 2027. Traditional phone lines are already being withdrawn in stages ahead of that date.
What happens if I do nothing?
Any service still running on a traditional phone line at switch-off will stop working, including phones, and potentially alarms, lift lines, door entry and older card machines. It is best to move across in good time rather than at the deadline.
Will I lose my phone number?
No. Your existing numbers can be kept and moved to the new digital service, so customers reach you exactly as before.
Is the replacement more expensive?
Usually the opposite. Digital phone systems typically cost less to run than traditional lines and include more features. We'll show you the costs clearly before you commit.
What about my alarm, lift or card machine?
These need checking individually. Some move to a digital line, others to a mobile or alternative solution. Our free line audit identifies every device that relies on a phone line so nothing is missed.
Book a free line & phone audit
No pressure, no jargon. We'll review your lines, phones and contracts and show you the options.