What does the 'Big Switch Off' mean for small businesses?

The Big Switch Off: What UK Businesses Need to Do Now?

The Big Switch Off is coming, and it’s something all UK business customers need to understand. BT Openreach is switching off the old copper phone network by 31st January 2027, which means traditional phone lines and analogue services are coming to an end.

What Is the PSTN and ISDN Switch Off?

For decades, PSTN (Public Switched Telephone Network) and ISDN (Integrated Services Digital Network) have supported phone services for UK business customers. However, both technologies rely on outdated copper infrastructure that is no longer reliable or fit for modern business needs.

Put simply, PSTN and ISDN are the services being switched off. The Big Switch Off refers specifically to the withdrawal of these copper‑based phone networks. If your phones, broadband, alarms, or payment systems still rely on PSTN or ISDN, those services will no longer work once the switch off is complete unless you move to a digital alternative.

As part of the ISDN switch off and the wider copper network switch off in the UK, Openreach is moving the country toward full fibre and IP‑based digital services. By 2027, the PSTN switch off in the UK will be complete. If your business still relies on PSTN or ISDN services, you’ll need to upgrade well before then to avoid disruption.

This move from analogue to digital isn’t just a technical change, it’s a crucial step in future‑proofing your business communications through digital network migration.

Why Upgrade to Digital Services?

Put simply, copper cables are not designed for today’s business demands. Fibre optic technology is faster, stronger, and far more reliable.

The key benefits of full-fibre include:

• Much faster broadband speeds

• Up to 10x faster, supporting multiple devices without slowdowns or buffering.

• Fewer faults and less downtime

• Fibre is more robust than copper, so issues are less frequent.

• More consistent performance

• Full fibre provides stable speeds, regardless of your distance from the exchange.

• Better phone systems

• Clearer calls, multiple calls at once, and access to your phone system from different locations, ideal for flexible and hybrid working.

This digital network migration doesn’t just replace traditional phone lines, it opens the door to smarter, more flexible ways of working.

What happens if I don't migrate my telecoms services?

While the final switch off date is 31st January 2027, not all areas will wait that long. Openreach has already begun switching off the copper network in locations where full fibre is ready.

If business customers leave the move too late, they may face:

• Limited engineer availability

• Short notice periods for upgrades

• Potential downtime if services are switched off unexpectedly

That’s why it’s best to start planning your digital network migration as early as possible.

Which Businesses Will Be Affected?

The short answer is all of them.

Every industry, from retail and healthcare to manufacturing and professional services will be affected by the Big Switch Off.

If your business uses:

• PSTN lines

• ISDN services

• Alarm systems, card machines, or other services running on traditional phone lines

You will need to move to a digital alternative, such as VoIP over full fibre.

In areas where full fibre is already available, suppliers can no longer provide new copper‑based services, making early action essential for business customers.

Preparing Your Business for the Future

The BT switch off businesses programme is already underway, and the move from analogue to digital is unavoidable. Acting now helps ensure your business remains connected, compliant, and competitive.

To find out how your business can follow the fibre and plan a smooth digital network migration, get in touch with our Telecoms team today or visit our digital migration page to learn more.