The Big BT Switch Off

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John Fisher 29 Sep 2023 Time to read: 

What is The Big BT Switch Off?

The ageing telephone network (Public Switched Telephone Network – PSTN) that has enabled business communications for many years is being switched off by BT in December 2025.  This will see the withdrawal of both PSTN and ISDN telephony services and services that use these (e.g. ADSL).  This will impact everyone, including businesses, currently using PSTN-based services.  Action needs to be taken now to plan an orderly migration to new services.

In some parts of the country these services have already been withdrawn impacting companies in these areas.


Why should you take action now?

Whilst technical solutions to replace these services are readily available the challenge for many companies is identification of affected services thus ensuring service continuity post December 2025.  PSTN & ISDN services have been the backbone of our telephony system for so long, with a nature of install and forget, records of these services and their current purpose is in most cases poor, and leads to confusion for business leaders about their exposure and risk.

If the switch off isn’t managed in a controlled manner not only will calls and broadband be affected, but other critical business services using legacy lines such as fire & intruder alarms, lift phones, CCTV, credit card machines and faxes.  Alternative processes will need to be designed for areas that rely on location identity transmission to emergency services.

By starting now organisations can do this in a planned orderly fashion avoiding resourcing stress close to December 2025.  We can support you with this challenge.

Need help? Don’t delay, get in touch today.


What is Peru’s Big BT Switch Off Assessment?

Peru’s experience in the Telecoms sector, is key to understanding which systems may be impacted by the switch off, ensuring decisions are based on installed services and the risk profile of these to the business.

We can:

  • identify your organisations risk exposure to the termination of the services
  • provide recommendations on solutions for:
    • Alarm & Broadband lines
    • Fax and Lift lines
    • Unused & dedicated phone lines
    • Aggregated Exchange lines (PSTN and ISDN) in PBX’s
  • advise on potential immediate savings on unused lines

We have a 3 step approach to delivery.


Your questions answered:

Won’t BT look after this for us, so there is nothing to worry about?

As with the switch over from Analogue to Digital television a few years ago, there are point solutions available but these may not be in your companies best interest and will be designed for BT to realise its requirement to turn off services.

Why not take the opportunity to develop a strategic solution allowing enough time to plan this in your change agenda, rather than being forced into point solutions.

Working with Peru to help you analyse the information will allow you to make informed strategic decisions.

I’m in IT and this is not part of my area and not under my budget, isn’t this a facilities issue?

Peru understand IT teams have an extraordinary workload at the moment and this might appear to be a facilities management issue, however all solutions will need IT involvement.  We can work with your facilities contacts to provide an idea of your companies exposure and the impact on your team allowing you to plan changes over the next couple of years.

December 2025 is a long way off, and there is a lot of time to deal with things before then. 

BT announced their intentions to switch off these service back in 2017 and has been slowly withdrawing services on new exchanges since.  We are now in the last third of a 9 year programme and many people are still unaware of The Big BT Switch Off or the impact that this will have on their companies.

Working with Peru will allow you to understand the impact and enable you to plan your exit from the services in an orderly fashion, we saw with the Digital television switch-off that there were timescale issues on some Digi-boxes as so many people left this to the last minute.  Peru believe this will happen in the consumer market and advise all our clients to sort this out as early as possible.

What products are affected?

  • PSTN – Public Switched Telephone Network
  • ISDN2/30 – Integrated Services Digital Network 2/30 Channels
  • LLU – Local-loop unbundling – allowing multiple telecoms operators to use connections from the telephone exchange.
  • SMPF / MPF – (Shared) Metallic Path Facilities: Allows companies to offer Broadband over copper telephone cables (PSTN), the shared function allows one company to offer the telephone whilst another offers the broadband.
  • ADSL – Asynchronous Digital Subscriber Line
  • SLU – Sub-loop unbundling Similar to LLU but allows for other operators to have street cabinets which tie into the main telco provided cabinet
Need help? Don’t delay, get in touch today.