BT confirms ISDN Switch Off

What are we talking about?

If you are reading this post you have likely heard the news that BT has announced their plans to switch off their PSTN and ISDN networks. We’ve noticed that the precise details of the plans vary massively from one source to the next, making it difficult for end users to plan for the future of their business.

In this post we aim to outline exactly what the “Switch Off” actually means and how this will effect UK businesses.

What is the Switch Off?

BT have indeed announced plans to switch off their PSTN (traditional copper analogue/ISDN) network in 2025. This is following an increasing decline in both live circuits and new sales with more and more customers turning to alternative products.

The Switch Off is being rolled out in phases:
Phase 1

December 2020 – BT will no longer be accepting any new orders or amend requests in Salisbury, meaning anyone looking to increases their line capacity will need to look at alternative products.

Phase 2

October 2021 – BT will will no longer be accepting any new orders or amend requests across 169 locations.

Phase 3

December 2022 – Salisbury PSTN network switched off completely.

Phase 4

September 2023 – Customers will no longer be able to place new orders or amends for ISDN across the whole of the UK.

Phase 5

December 2025 – The Big Switch Off! All PSTN services will be switched off.

Ofcom, the UK’s communications regulators, have released the following statement with regards the future of fixed line services.

Ofcom – Fixed Line Future

What should I do now?

Ideally, everyone with existing PSTN and ISDN services really needs to start looking at alternative solutions. The good news is, there are a few to choose from and each is as tested and reliable as the last. For example:

Hosted VOIP

Hosted VOIP is a very popular solution for many reasons, including unrivaled flexibility, very low initial purchase costs and reduced ongoing costs whilst maintaining all the features of a traditional telephone system plus more!

Find out more
SIP Trunks

SIP Trunks are an equally popular choice, often with a small upgrade to your existing setup you can connect your current equipment to VOIP technology and benefit from all savings and features that come with it without any changes to your day to day running.

Find out more


In short, ISDN and PSTN have reached the end of their life, this is because more efficient and productive products are now readily available and quickly taking over. Meaning the traditional methods are no longer required.

The good news is, with our help, the transition from traditional to future-proof really is a painless and hassle free experience.

Get in touch with our team today for some friendly and professional advice. They will walk you through all the best available options ensuring we find the best product for your requirements.

Get in touch today!

What does it all mean?


Firstly, what is PSTN? PSTN stands for Public Switched Telephone Network. As far as you and I are concerned this refers to analogue lines (we would call it a telephone line). Each line will usually be associated with a single telephone number and these lines are generally used for the transfer of voice and data.


Next, what is ISDN? ISDN stands for Integrated Services Digital Network. We would call these digital lines and these are popular amongst many businesses because of their flexibility for example ISDN allows for multiple numbers on each channel giving business the ability to give staff individual direct dial numbers without the need to have multiple physical lines.


For more information, download Openreach’s FAQ’s here: Download FAQ’s

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