If your business still runs on a traditional landline or an ISDN phone system, there's a hard deadline you need to know about: 31 January 2027. That's the date Openreach will permanently switch off the UK's old copper telephone network — the Public Switched Telephone Network, or PSTN — along with ISDN, the digital service that runs on top of it.
This isn't a soft target or an industry rumour. Openreach has confirmed the date is fixed, and in many parts of the country the countdown has already started.
What's actually being switched off
Two things are ending, and it's worth knowing the difference:
• PSTN is the underlying copper network that's carried UK phone calls since the Victorian era. It's what your standard analogue landline runs on.
• ISDN is the digital layer many businesses use on top of that copper network — usually as ISDN2e or ISDN30 lines feeding an on-site phone system.
Both rely on the same ageing copper infrastructure, so both are being retired together. Openreach stopped taking new ISDN orders back in September 2023, and full-scale migration has been under way since 2023 through a rolling programme of local “stop-sell” dates, ahead of the final nationwide cut-off in January 2027.
Why it's happening
Openreach's copper network is decades old, expensive to maintain, and increasingly unable to support how businesses actually communicate today. The replacement is an all-IP network — voice and data carried digitally over fibre broadband, using technologies like VoIP (Voice over Internet Protocol). It's more reliable, easier to scale, and works from anywhere with an internet connection, not just a fixed phone socket.
What happens if you do nothing
This is the part that catches businesses out. It's tempting to assume the switch-off is “just the phones” — but anything in your business still relying on a standard phone line is affected, including:
• Phone systems — analogue handsets and ISDN-based PBX systems
• Card payment terminals that dial out over a phone line
• Alarm and security systems , including some CCTV and monitored intruder alarms
• Lift and door entry phones
• Fax machines
• Older broadband connections — standard ADSL and some FTTC services also depend on the copper network
If you haven't migrated before your local exchange switches off, you won't get advance warning that day — the line will simply stop working. Left unmanaged, that can mean lost calls, failed card payments, or a lift line that no longer connects to anyone.
When does it actually affect you?
The national deadline is January 2027, but many exchanges are being migrated earlier as part of Openreach's phased rollout, and stop-sell restrictions are already in place across large parts of the country — meaning you may not even be able to order or amend a copper-based service in your area right now. In practice, that means your personal deadline could be well before 2027, depending on your exchange.
The good news: migrating is more straightforward than it sounds
• Numbers port across. Your existing landline numbers move to your new digital service — no need to reprint stationery, update your website, or tell every customer you've changed number.
• It's often cheaper, not more expensive, once you compare the ongoing cost of legacy lines (which are already rising in price) against modern alternatives.
• It future-proofs the way your team works — digital phone systems work from a desk, a laptop, or a mobile, which matters if any part of your team works remotely or across multiple sites.
What to do now
1. Audit what's connected to a phone line — don't just think about handsets. Check alarms, payment terminals, lifts, and any older broadband connections.
2. Find out your exchange status — some areas already have restrictions on ordering new copper services.
3. Get a plan in place before you're forced into one. Businesses that leave it late tend to end up migrating in a rush, at a time they don't control.
Frequently asked questions
Do I need to change my phone number?
No. Your existing numbers can be ported across to a digital service, typically within 10–15 working days.
Will call quality be worse over the internet?
No — modern digital phone systems generally offer better call quality than ageing copper lines, provided you have a stable broadband connection.
What happens if I do nothing by the deadline?
Your line will simply stop working when your exchange is switched off, along with anything connected to it — including alarms and payment terminals.
Is this happening everywhere in the UK at once?
No. It's a phased rollout by exchange area, so your local cut-off could be well ahead of the national January 2027 deadline.
Getting your business ready for the switch-off doesn't need to be complicated. Turnkey Telecom Solutions can review what's currently connected to your lines and map out a migration path with no surprises — book a free line audit to find out where you stand.
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