The PSTN Switch-Off: What Every Business Needs to Know Before January 2027

What’s the PSTN switch-off?

The Public Switched Telephone Network — the copper wire telephone infrastructure that’s been in use since 1876 — is being permanently retired across the UK.

BT Openreach, who runs the largest chunk of it, is replacing the whole thing with a fully digital, internet-based system. All voice calls will route over IP (Internet Protocol) instead of copper. This affects every business in the country, regardless of size or sector.

When is it happening?

The original deadline was December 2025. That’s been pushed back to 31 January 2027, primarily due to complications migrating vulnerable customers who rely on telecare alarms and similar safety-critical devices.

That delay might sound like breathing room. It isn’t.

The migration process for a business with multiple sites, legacy equipment, or complex phone setups can take 6–9 months minimum — and that’s before you factor in testing and any issues that crop up. If you start in late 2026, you’re cutting it very fine. If something goes wrong, you could lose phone service entirely.

The sensible window to act is now.

Why does this affect more than just your phones?

This is the bit most businesses miss. The switch-off isn’t only about phone calls. The PSTN underpins a surprising range of equipment that businesses use every day:

• Door entry and intercom systems — many connect over analogue lines
• Intruder and fire alarms — older alarm signalling systems use PSTN to communicate with monitoring stations
• Lift emergency lines — legally required to work, and many run on copper
• CCTV and access control — some systems dial out over PSTN
• Card payment terminals — older EPOS systems often use a phone line as a backup or primary connection
• Fax machines — will stop working entirely

If any of this applies to your business, those systems need to be audited and migrated separately from your phone lines. It’s not just a case of swapping handsets.

What does the PSTN get replaced with?

VoIP (Voice over Internet Protocol) is the main replacement. Calls are made over your broadband connection rather than a copper line. The quality is typically better, the features are more advanced, and the cost is usually lower than maintaining legacy lines.

For businesses, this typically means moving to one of the following:

• A hosted cloud phone system — your phone system lives in the cloud, no on-site hardware required. Calls, voicemail, call routing and more are all managed online. This is what we’d recommend for most businesses.
• SIP Trunking — if you have an existing on-site phone system you want to keep, SIP trunks replace your traditional phone lines and connect your existing system to the internet.
• Microsoft Teams calling — if your business is already in the Microsoft 365 ecosystem, Teams can handle voice calls with the right setup.

The right option depends on your current setup and what you actually need your phone system to do.

What should you do right now?

Step 1: Audit your lines

Find out exactly how many lines you have, what they’re used for, and what equipment depends on them. Include alarm lines, lift lines, door entry systems — not just the phones on desks.

Step 2: Check your broadband

VoIP depends entirely on your internet connection. If your broadband is unreliable or slow, voice quality will suffer. This is a good time to review whether your current connection is fit for purpose — and whether FTTP or a leased line makes more sense.

Step 3: Get a plan in place

Work with a telecoms provider (like us) to map out what needs replacing, what can be adapted, and in what order. Some migrations are straightforward. Others take planning.

Step 4: Don’t leave it to the last minute

Businesses that wait will be competing for engineer time and equipment alongside every other company that’s also left it late. Early movers get better pricing and a smoother rollout.

Already on a digital phone system?

If you’ve moved to a cloud phone system or VoIP in recent years, you’re largely covered for the phone side. But it’s still worth checking your alarm lines, lift lines, and any other legacy connections — these are often overlooked even by businesses that think they’ve already sorted the switch-off.

How Microcare can help

We handle the full picture — from auditing your existing lines and equipment through to recommending and installing the right solution for your business. Whether that’s a 3CX cloud phone system, SIP trunks, or helping you sort out that alarm line that nobody’s thought about in years — we’ll get it sorted.

Call us on 0161 763 8801 or use the contact form below and we’ll arrange a free audit of your current setup.

The PSTN switch-off deadline is 31 January 2027. The time to act is now.