The BT PSTN & ISDN Switch Off

The WLR Withdrawal process is accelerating; are you ready?

Home > WLR Withdrawal – The Big PSTN & ISDN Switch Off

What you need to look for?

The switch off will effect businesses and organisations in many ways.

We recommend you have a look at your bill to see if any of the below are in use:

ISDN30, ISDN30e, ISDN2, Analogue Line, Business Line, PSTN Line


These could be used for:

  • Alarm lines, Lift lines, PDQ/EPOS lines, Fax, Modem, Powerfail, Telephone systems
  • If you have an on-site PBX, telephone line, fax line, PDQ line or broadband line, you will be affected and need to make a plan to switch over.


    How would you like to be contacted

    Clicking submit accepts terms of use.

    Upgrading the Access Network

    BT & Openreach’s decision to switch off the Public Switched Telephone Network (PSTN) & Integrated Services Digital Network (ISDN) is mainly due to both technologies becoming out of date and expensive to operate and maintain.


    Openreach plans to invest more into modern-day technology and hence focusing instead on deploying fibre infrastructure and future-proofing their network across the UK.


    Any individual or organisation still using these traditional voice services will need to have moved to newer SIP and IP voice solutions in the near future. If not, then they simply won’t be able to use their phones or any service that is being delivered using a PSTN

    No more dial tone; alternatives?

    SIP and VoIP

    The terms SIP and VoIP refer to telephony based services delivered using Internet Protocol (IP) signalling.


    What is SIP?

    SIP services are generally used to connect lines to a telephone system and these are a direct replacement for the ISDN technology.


    It is designed to support real-time multimedia sessions between groups of participants. In addition to telephone calls, SIP can also be used to set up video and audio multicast meetings, or instant messaging conferences.


    What is VoIP?

    This is a general term used to describe routing voice calls over an IP network.


    The term is closely associated with hosted telephones, where a telephone system installed at a customer’s premises is replaced with a central system shared between many different locations.


    Flexible VOIP telephony systems can be delivered fully hosted in the Cloud, on-premise or a combination of both (hybrid).


    They are easy to manage and incorporate a number of features including instant chat, video conferencing, screen sharing and phone calls through mobile apps.

    Don’t panic; be prepared Engage with an industry professional to better understand your options.

    AdEPT has been delivering PSTN & ISDN services since 2003 and has years of experience providing communication solutions to business and organisations.


    Our latest range including SIP and VoIP solutions, refining our portfolio to best match out customers’ requirements.


    We have already developed a number of IP and VoIP services, replacing current PSTN and ISDN services for many clients, and would be happy to discuss the benefits of these over your current solution.


    We’re offering both new and existing customers alike the opportunity for a free telephony audit.


    This audit will review all of the telephony services currently supplied to your business, providing a report on the services and a recommendation of the actions needed to prepare for the withdrawal of the copper network in 2025.


    The Public Switch Telephone Network, was introduced in the 1800 and is a circuit-switched analogue telephone system that enables the transmission of voice and data (broadband) through a network of copper wires. This system is also referred to as landlines, Plain Old Telephone Service (POTS) or fixed-line.


    PSTN is used by residential and business customers.


    Integrated Services Digital Network (ISDN) allows for simultaneous digital transmission of voice, video and data services over the traditional PSTN copper network. This is mainly used by businesses to support multiple users to make & receive calls at the same time, over the same link, using different channels to keep the traffic separate.


    ISDN comes in a number of options:


    Mainly used by small businesses. With ISDN2e you can connect up to 60 channels. Channels are sold in pairs and can be bonded to increase bandwidth for things like video conferencing.


    This is designed for businesses that need high-quality video conferencing, consistent transfer of large data files, or that operate call centres.


    Each connection provides 8-30 independent 64k channels. You can combine these for bandwidth intensive applications such as high-quality video conferencing or large data file transfers.


    This is the same as ISDN30 but with some additional features like Customer controlled Call Forwarding and Call Deflection.


    Wholesale Line Rental (WLR) allows alternative suppliers to rent access lines on wholesale terms from Openreach, and resell the lines to customers, providing a single bill that covers both line rental and telephone calls.

    How can we help?

    AdEPT empower organisations by uniting their technology, networking and data, providing seamless communication and the confidence to innovate. All underpinned by the latest security. And all with minimal fuss. We are perfectly placed to deliver a service you can trust. You can read more about some of our recent work in this area, by reading our case studies.