Landline replacement

Prepare for the PSTN switch off

We’re all familiar with the copper wire telephone network: in use since 1876, it’s kept business communications’ going for years. But that’s all about to change.

In 2025, the Public Switched Telephone Network (PSTN) is being switched off by BT Openreach, which means everyone, including businesses, currently using PSTN-based services will need to move to another service before then.

The alternative? Voice over Internet Protocol (VoIP), a solution that transmits voice calls and data using an internet connection.

This is a major step towards the United Kingdom’s mass IP-network migration, with VoIP core networks set to replace all the legacy PSTN services in just a few years’ time.

Embrace the future of telephony by replacing your landline with VoIP before the Public Switch Telephone Network (PSTN) is switched off in 2025.

What is the PSTN Switch Off?

What dates do I need to know?

PSTN Switch Off and Landline Replacement Timeline

Interactive PSTN Stop Sell Map - Priority Exchanges

Keep track of the UK's march to All IP

In parallel to switching off the PSTN network, Openreach are rolling out their fibre broadband network.

To expedite the transition between networks, they have identified and published a list of Priority Exchanges throughout the British Isles where they will be focussing their efforts to get FTTP (Fibre-to-the-Premises) rolled out. When FTTP is available to more than 75% of properties within the catchment of an exchange then they will move to Stop Sell with WLR products, meaning everyone (business and consumer) will need to move to an IP service for new orders.

The current list of Priority Exchanges and their intended Stop Sell dates are shown in the map below (dates correct at time of publication).

How do I use this Priority Exchange Switch Off Map?

This map plots which exchanges will undergo a “stop sell” as the nation moves to an All IP.

Openreach has announced 297 priority exchanges for stop sell of PSTN services by April 2022

You can track which exchanges are switching off, and when via our map

  • This map is built on Google Maps, and so can be navigated as you would use any online map
  • The priority exchanges have been categorised into 4 “tranches” which go in order of “stop sell” dates – these can be viewed on the left-hand side of the map
  • Each Exchange has detailed information including exchange code, postcode, SI number, stop sell date, and helpful FAQ’s.


Frequently Asked Questions

What's happening?

BT Openreach has announced it intends to switch off the traditional, copper-based telephone network in 2025. This is commonly referred to as the PSTN Switch Off.

While 2025 may seem a while away, from December 2023 you won’t be able to purchase any new ISDN or PSTN-based services, with many locations affected by a stop sell much sooner than that.

Why should I care?

The PSTN Switch Off will affect all businesses currently operating using PSTN and ISDN services. If you fall into this category, you will need to move to the new network to keep your phone and your number working.

The All IP network delivers voice calls using the same infrastructure as data and using VoIP (Voice over Internet Protocol) technology.

What is VoIP?

Simply put, VoIP uses a company’s existing internet connection to transmit voice calls. When it was first introduced, this solution seemed like a dangerous choice, as it completely relies on the quality of the internet connection to guarantee stable calls.

Nowadays, the speed of most broadband is fast enough to negate any problems around call quality. VoIP telephony is a simpler option than it sounds, requiring a lot less hardware than legacy systems.

It is delivered by Over the top (OTT) applications to which new features are added regularly, it gives your business more flexibility and it can be used on a variety of devices – from desk phones to mobiles, tablets, and computers.

Direct Access

What about my Special Services?

The migration will also impact services like security and fire alarms, telecare devices, retail payment terminals and equipment for monitoring and controlling networks.

These rely on some features of the PSTN that are not fully replicated in VoIP-based platforms and could have implications for both domestic and business customers, as well as public sector users. BT have made their testing facility available to manufacturers and despite the pandemic and lock-downs, there is already a list of who has tested their equipment on the new All IP network which can be found here:

All IP Knowledge Hub

Read through our guides, articles and blogs

Knowledge Hub

PSTN Switch-Off: Everything You Need to Know

BT Openreach announced the end of PSTN and ISDN back in 2015. The telecommunications service provider began shutting down networks in 2020 and will stop taking new orders starting 2023. By December 2025, PSTN circuits will be shut off completely.

This article tells you everything you need to know and how to get prepared.


Knowledge Hub

The micro business guide to phone systems

People still like to talk, the difference is what we use to make and receive calls is changing.

Landlines are out – Voice over IP is in. Read the guide to see how the UK infrastructure is changing and how you can prepare with the right technology.

micro business guide to phone systems

Knowledge Hub

Simple Landline Replacement Recipe

With a sprinkle of preparation, a dash of great connectivity and a fresh internet-based phone system, you can have the perfect telephony solution for your business in just three simple steps.

Simple Landline Replacement Recipe


Products that can help you prepare.