PSTN Switch-Off: UK Businesses Have Six Months Left

The UK’s copper telephone network will permanently shut down on 31 January 2027. Openreach – the company that owns and operates most of Britain’s telephone infrastructure – has confirmed that there will be no further extension to the deadline. With six months left, Openreach’s own figures show that around 350,000 business premises in the UK still have not migrated away from the old copper lines.

If your business is among them, this post explains what is going away, what is at risk, and how to make sure you are not left without working phones – or worse, with alarms and payment terminals that simply stop functioning – when the switch-off happens.

What is the PSTN, and what is actually being switched off?

PSTN stands for Public Switched Telephone Network – the traditional copper wire system that has carried phone calls across the UK for over a century. Related services built on the same infrastructure include:

• ISDN (Integrated Services Digital Network) – used by many businesses for office phone systems and data connections
• ADSL and FTTC broadband – these connection types run partly over copper and will also be affected
• Standard analogue lines – used for phones, fax machines, and other devices

From 31 January 2027, all of these services will be deactivated permanently. Any device or system that relies on the copper network will stop working.

It is not just your desk phones

Most businesses have already replaced their main telephone handsets with a digital or internet-based system. The larger risk lies with equipment that quietly runs in the background on copper lines that nobody has thought to check. This commonly includes:

• Payment card terminals – many older card machines dial out over an analogue line rather than broadband or mobile data
• Burglar alarms and fire alarm monitoring panels – systems that report alerts to a monitoring station often use analogue lines to do so
• Lift emergency call lines – lifts are legally required to have a means of summoning help; many use analogue connections
• Fax machines – still in use in some legal, professional, and healthcare settings
• Door entry and intercom systems – some models dial out through the copper network
• ISDN-based PBX phone systems – if your office phones connect via ISDN30 or ISDN2 lines, those lines will be gone

The cost of inaction is already rising. Openreach increased wholesale charges for remaining copper lines in July 2026, so businesses still on legacy connections are now paying considerably more than a year ago – for a service that will disappear regardless.

What you should do before January 2027

1. Audit everything that uses a phone line. Do not limit this to handsets. Include your alarm system, lift, door entry system, card terminals, and any other device that dials out. If you are not sure, check with your facilities team, alarm company, lift maintenance contractor, and card payment provider.

2. Talk to your alarm and security supplier now. Ask whether their equipment is compatible with digital voice services (also called VoIP). Some systems work fine with an adaptor; others may need a new panel. Lead times for security equipment can be several months, so this conversation cannot wait until December.

3. Check your card payment provider. Most modern card terminals use 4G or broadband connectivity, but older models may still use analogue. Your payment provider can confirm this and advise on a replacement if needed.

4. Move your phone system to VoIP. VoIP – Voice over IP – is internet-based telephony and the standard replacement for ISDN and analogue lines. A modern cloud phone system such as 3CX gives you all the features of a traditional office system – voicemail, call groups, conference calling, call recording – plus the flexibility to take calls anywhere, on any device. Your existing phone numbers can be ported across, so clients will notice no difference.

5. Upgrade your broadband if needed. If your business uses ADSL or FTTC broadband, you will also need to move to a full-fibre connection. Most UK business premises can now access full-fibre broadband, and the performance improvement over older copper-based connections is significant.

What does migration cost?

For most SMBs, moving to a cloud phone system is cost-neutral or cheaper in the long run. There is no on-site PBX hardware to maintain, monthly per-user costs are typically lower than equivalent ISDN line rental – particularly now that legacy line prices have risen – and call costs with VoIP are generally lower too.

The migration itself requires planning: number porting, handset configuration, and testing call routing before going live. Starting now means you have time to do this properly and work through any issues, rather than rushing in December when every telecoms provider in the country will be overloaded with last-minute migrations.

How System Force IT can help

We deploy and manage 3CX cloud phone systems for businesses across Gloucestershire and throughout the UK. We can audit your existing telephony and identify anything that will stop working after January 2027 – then handle the full migration, including number porting, handset setup, and integration with your existing IT infrastructure.

For clients on our managed IT support plans, we proactively review your systems and flag PSTN-dependent equipment as part of our regular service. For businesses not yet working with us, our IT consulting team can carry out an independent telephony audit and give you a clear picture of what needs to change and in what order.

The January 2027 deadline will not move. If you would like to get ahead of it, get in touch or call us on 01452 701355 for a no-obligation conversation about your options.