The UK PSTN Switch-Off: What Your Business Needs to Do Before January 2027
In 2024, reported PSTN network faults jumped 45%. That’s not a coincidence. The UK’s old copper phone network is being switched off in January 2027, and it’s already starting to fail under its own age.
If your business still runs on PSTN or ISDN lines, the clock is running. Here’s what’s changing, what it affects, and what to do about it now.
What is the PSTN switch-off?
PSTN stands for Public Switched Telephone Network. It’s the analogue system that has carried UK phone calls over copper wiring for decades. ISDN, introduced in 1986 to add digital capacity to that same copper network, is being retired at the same time.
Openreach is switching off both networks nationally by January 2027. Every business still relying on these lines needs to move to IP-based telephony before then.
This isn’t a UK-only shift. Estonia and the Netherlands have already completed their switch-off. Germany, Japan, and Sweden are mid-transition. The UK is simply catching up to where voice communication is already heading.
Why it matters beyond your phone lines
Most businesses think of this as a phone system upgrade. It’s bigger than that.
A wide range of equipment quietly depends on PSTN, ISDN, or ADSL connections, including:
- Door entry and access control systems
- Intruder alarms and monitored security systems
- Point-of-sale machines and card readers
- Telecare and health monitoring devices
- Older broadband connections
If any of this runs through your business, it needs reviewing before the switch-off, not after. Waiting until January 2027 to find out your alarm system stopped reporting to its monitoring centre is not a good plan.
What replaces PSTN and ISDN
The replacement is IP telephony: voice and data carried over the internet instead of copper wire. Cloud telephony is the most common form businesses adopt, using VoIP to deliver calling features without on-site hardware.
The practical benefits for a business are straightforward:
Work from anywhere. Staff can make and receive calls on any device, from any location, using the same business number.
Fewer systems to manage. IP telephony integrates with the tools your team already uses: video calls, collaboration platforms, CRM systems.
Lower overhead. Cloud-based systems remove the cost and maintenance of on-premise phone hardware.
Built-in resilience. No dependency on ageing copper infrastructure that’s already showing a 45% rise in faults.
What you should do now
- Audit your connections. List every system in your business that runs on a phone line: main phone system, alarms, door entry, card machines, broadband. Don’t assume IT has already mapped this.
- Check your broadband. If you’re still on ADSL, you’ll likely need to move to fibre to support IP telephony properly.
- Plan the migration, don’t wait for the deadline. Openreach has already stopped new PSTN and ISDN orders in most areas. The businesses that migrate early avoid the scramble, and the risk, that comes with leaving it to the final months before 2027.
- Get a like-for-like comparison of your options. Cloud telephony, SIP trunking, and hybrid setups all solve this differently depending on your size and how your teams work.
How Fusion Telecoms can help
We’ve helped businesses across the Dorset, Hampshire and Sussex move off PSTN and ISDN onto IP telephony with no disruption to daily operations. We’ll audit what you’re currently running, flag anything at risk before 2027, and map out a migration that fits your business, not a generic template.
Get in touch for a free migration consultation. The earlier you plan this, the more choice and the less risk you have. Contact Fusion Telecoms today to get started.
