The PSTN switch-off is happening... and it’s happening now.

You may be aware that BT plans to decommission all analogue PSTN and ISDN lines in 2025 but in fact the process has already begun. In exactly 12 months’ time, from September 2023, businesses will no longer be able to purchase new analogue or ISDN lines, and that includes ADSL and FTTC broadband services.

To help prepare your organisation and future-proof your infrastructure we have pulled together some key information that you will need to know.

What is the PSTN and ISDN switch-off?
In November 2017, BT Openreach announced their timescales to switch off analogue and ISDN lines in 2025, affecting PSTN-based services and some broadband services. Digital demands on networks for organisations and homes have vastly changed and the underlying technology needs to reflect and support modern requirements.

Which services will be affected?
If your organisation is using analogue telephone lines, ISDN or broadband services running over analogue lines, at the end of December 2025 these will be switched off and become end of life.

These include:

  • Analogue phone lines (including dial up devices, fax, modem, and PDQ machines)
  • ISDN (ISDN2 and ISDN30)
  • Some broadband services (ADSL, Max, 2+ and FTTC circuits)

Key dates within the ISDN/PSTN switch-off
BT Openreach is taking a phased stop-sell approach at individual locations between December 2020 to August 2023. When a location has met its stop sell deadline then analogue and ISDN lines cannot be purchased or have additional features or changes made to existing services.

More information, including stop-sell dates for each location, can be found via the following link:

How to prepare for the ISDN/PSTN switch-off
If you are still in contract with a line that is coming to end of life, such as PSTN or ISDN, you need to start looking at your current technology and get prepared following the tips below:

  1. If you are renewing contracts, look to move to a future-proofed IP-based solution.
  2. If you are moving to a new premises or opening a new site location, take this opportunity to explore IP-based connectivity options rather than analogue or ISDN.
  3. If you are reviewing your existing telephony options and you are using an on-site PBX with analogue or digital inbound/outbound lines, review the market for suitable options including IP telephony and Microsoft Teams.

What is Net Technical Solutions doing?
We are working closely with our telephony and connectivity providers as well as our customers to plan ahead for the PSTN/ISDN switch-off. Our advice to customers renewing connectivity or telephone contracts over the next 3 years is to speak to one of our sales team here at Net Technical Solutions and review the different options including SoGEA circuits, to get your business IP-ready and future-proofed.

Additionally, we are asking customers to consider more than just telephony and connectivity, but also their internet connected devices as well (including alarm systems and PDQ machines, etc.) to ensure that they are IP enabled for their new connectivity options.

Alternatives to PSTN and ISDN
If you are still using a traditional on-premises PBX or using analogue telephone lines your organisation will need to be aware that these legacy service offerings will shortly be unavailable and ultimately switched off.

For customers that are currently using PSTN or ISDN services to connect their on-premises PBX platforms, we can provide an IP-based alternative service. Net Technical Solutions has many years of experience in providing VoIP telephony through Microsoft Teams, Teams Direct Routing, Gamma Horizon and 3CX, depending on each customer’s needs and requirements.

If you have sites connected with traditional copper broadband, e.g. ADSL Max, 2+ or FTTC, the broadband is delivered over an analogue phone-line and will therefore need to be replaced by FTTP (Fibre to the Premises) or SoGEA before switch-off in a couple of years. Typically, customers with small offices, large estates of small branch offices, and remote workers will use these cost-effective broadband connections, and Net Technical Solutions will work closely with each customer to find the right solution for their individual needs.

Get in touch about the PSTN and ISDN switch-off
If you have any questions about the PSTN and ISDN switch-off, then please contact your Account Manager or our sales team, who will be happy to discuss your current infrastructure and help create a personalised timeline to get your ready in time.


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