7 min read

BT switch off analogue phones

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Technology constantly moves forward and this is true for our phones systems and business telephony. Some time ago, BT announced that they were retiring their PSTN and ISDN network, becoming end of life by 2026. This means that if you use analogue, traditional landlines or ISDN in your business, you will have to move to cloud telephone (VoIP) by December 2025.

Here is everything you needs to know about BT switching off analogue telephones and what your business should do if your phones, fax, fire alarm or payment machines currently use telephone landlines. Our video and guide explain:

What is the PSTN network?
What is the ISDN network?
When is PSTN and ISDN being switched off?
Why is BT retiring PSTN and ISDN?
How will it affect my business?
How do I switch to VoIP/cloud telephone?
VoIP: Opportunity to improve business operations
How can Superfast IT help?

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What is the PSTN network?

PSTN stands for public switched telephone network and has been in place for the last 50-60 years. PSTN is more commonly known as landline or analogue. At home, we typically use PSTN to make phone calls and businesses have been making use of PSTN over this timeframe too.

Phone systems modernising - old telephone exchange

The PSTN infrastructure/network dates back to when phone operators would sit in telephone exchanges connecting people. Since then, switching boards have become automated and the PSTN network has been maintained through patches, repairs and updates, but much of the infrastructure remains the same.

A network of copper cabling runs underground and overhead with telephone lines and this is what comprises the legacy telephone infrastructure (PSTN) and what you would call the country’s traditional telephone network. Some of the copper cables buried underground are very old and have formed part of infrastructure since the 19th century.

The copper network, by today's standards, is slow, outdated and inefficient compared to the modern-day alternatives including VoIP/fibre broadband. VoIP stands for ‘voice over internet protocol’ and is also commonly known as cloud telephone, internet telephone, IP telephony, or broadband phone, carrying calls over data networks.

What is the ISDN network?

ISDN stands for Integrated Services Digital Network. It was an upgrade to PSTN introduced in 1986 by BT. It runs on top of PSTN cabling and was the first digital communications system. At the time it was faster compared to PSTN, but again, compared with today's standards, it is slow and outdated. This too is being decommissioned by the end of 2025.

When are PSTN and ISDN being switched off?

BT will be retiring PSTN and ISDN by December 2025. BT are shutting it off and these networks will not work past this date.

Why is BT retiring PSTN and ISDN?

There are a number of reasons why BT are switching off analogue phones and embracing a shift to modern cloud telephony. These are:

  1. Shift to VoIP

    BT are retiring PSTN and ISDN because there has been a huge shift towards VoIP traffic and people utilising VoIP/internet/cloud to make phone calls. VoIP, internet and cloud telephony all means the same thing; using the internet to make telephone calls.

    VoIP keeps up with the demands of modern-day communications demands - download speeds, volume, quality - and is much faster than PSTN and ISDN.

  2. Save money with VoIP

    Many businesses have made the switch to cloud telephones to save money. We have seen clients save up to as much as 40% on phone bills by switching to VoIP.

  3. Increased use of smartphones, apps, Zoom, Teams

    The way in which we communicate has transformed over the past 20 years. We now have many more modes of communication. Lots of us choose not to use traditional telephones, embracing new technology and different ways of communicating. These include:

    • Mobile phones/smartphones (iPhones)

    • Apps such as WhatsApp, Telegram, Kick, WeChat, Badoo, Google Hangouts, Facebook Messenger

    • Social media and forums such as Reddit, Facebook, Instagram DM, LinkedIn inboxing

    • Zoom and Teams

    The list is endless, there are so many online hangouts today. All of these platforms are used to communicate instead of using traditional landlines.

  4. Decline use of landlines

    Following on from our last point, with the increased use of the cloud, smartphones and apps, there has been a rapidly declining use of PSTN.

  5. Not economical to maintain PSTN and ISDN networks

    So many people have already switched to cloud telephony that it's not economical for BT, BT Openreach and the other big providers to maintain the old PSTN and ISDN networks. Ultimately the large telecommunications companies; BT, Virgin Media and Vodafone, have driven the decision, which has been down to cost.

  6. Passed by the telecoms regulator, Ofcom and government

    The UK government has not been involved in making the decision to switch off the PSTN service but the switch off has been passed by the government and Ofcom.

How will it affect my business?

If you have a phone that just uses PSTN or ISDN, it won't work past the end of 2025. If you have PSTN or ISDN, if you want to be able to make use of your telephone and make calls, you need to make sure that you've moved that over onto a VoIP service by that time.

BT Openreach predicts around 16 million lines and channels will need to be upgraded to alternative products over the next few years. Apart from your phones are going to stop working, you may also utilise the PSTN network for things like:

  • Fax machines
  • Card payment machines
  • Alarm systems
  • Fire systems

These, too, will need to be switched to cloud telephone by December 2025.


switching to VoIP/cloud telephone

Anyone using traditional phone lines will need to switch to VoIP by December 2025. But there's no need to worry, telephones, fax machines, card payment machines, alarm and fire systems can all be switched to the internet, VoIP systems:

  • Adaptors such as ATA devices can convert your old, existing PSTN equipment and make them cloud-ready
  • You will keep your telephone number
  • The transition process is easy and does not affect operations.

VoIP: opportunity to improve business operations

It's always to improve efficiency. The PSTN network switch-off is an opportunity to improve the efficiency and flexibility of your business operations. Cloud telephony has been particularly popular during COVID to facilitate remote working.

VoIP/cloud telephony is decentralised from your office. This means you don't need to be in the office to access the telephone system - all you need is an internet connection. Cloud telephony systems have allowed businesses to maintain flexible operations during the pandemic. Cloud telephone systems enable team members to answer phones from not only your desk. With cloud telephony you can answer a call by using laptops, tablets and mobiles - from anywhere - at home, the office, in cafes - as long as there is an internet connection, you can answer the phone.


How can Superfast IT help?

Here at Superfast IT, we offer cloud telephony. The cloud telephony system we use sits in the cloud. The only equipment you need is your desk phone, mobile or laptop because VoIP uses your existing Internet connection to make phone calls.

Make the next step by scheduling a meeting with one of our experts to discuss your telephone and we can provide you with a hassle-free, great value business solution.

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