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2025 BT Switch Off – PSTN and ISDN

2025 BT Switch Off – Get Switched On
The 2025 BT Switch Off is approaching, is your organisation prepared?

As the 2025 BT Switch Off is getting closer, the UK is preparing for a huge technological change. Tel Group are here to help your school or business navigate this transition.

BT Openreach have announced that by 2025 their existing PSTN (Analogue) and ISDN (Digital) network will be switched off entirely, switching to a single Internet Protocol (IP) network. But what does this actually mean for your organisation?

By December 2025, the Public Switch Telephone Network (PSTN) and the Integrated Services Digital Network (ISDN) will be switched off entirely, meaning every phone line in the UK is required to move to a fully digital network, routing calls over Internet Protocol (IP) rather than traditional lines.

However, it’s not just your phone services you need to consider, everything that currently utilises PSTN and ISDN will also become obsolete. This may include your broadband (ADSL and FTTC), alarms, door entry systems, CCTV, faxes, and much more. 

Now is the time to get ahead of the change and upgrade your lines before they become obsolete.

Get in touch to organise a free site audit and obtain a free quotation to find out exactly how much you’ll save!

Contact us to get started on upgrading your traditional lines before the 2025 BT Switch Off!

Join the 700 schools and businesses who have already transitioned from ISDN and PSTN to a futureproof and cost-effective modern alternative with Tel Group.

2025 BT Switch Off- Your traditional lines will be switched off 2025 BT Switch Off- Your traditional lines will be switched off

What is happening?

BT have started to phase out their ISDN and PSTN lines, with the intention to switch off these lines for good by 2025.

Essentially, this means that your school or business will be forced to replace these lines and all connected equipment in order to make way for the newer, cheaper and more efficient alternatives, VoIP and SIP.

What connected equipment will be affected?

Not only will your telephone systems be affected, additional connected equipment will also become obsolete. The main thing to consider is your broadband. If your current broadband connection operates using the ASDL or FTTC network, you’ll also need to switch your broadband over to FFTP or SoGEA. 

Any equipment that currently uses the PSTN and ISDN will stop working: alarms (lift, fire, intruder alarms etc), door entry systems, CCTV, faxes, and so on.

You will need to ensure that these products are compatible with the new IP technology standards. 

VoIP and SIP Telephones to replace Analogue & Digital Lines ahead of the 2025 BT Switch Off VoIP and SIP Telephones to replace Analogue & Digital Lines ahead of the 2025 BT Switch Off

Why is this happening?

Unfortunately, traditional lines no longer meet the demand for new technology, seeing them offer a limited number of benefits. Copper connections which are widely used in schools at present do not meet the DfE standards. 

Additionally, traditional phone lines are made up of old technology which means your maintenance is much more frequent and costly.

The new network will provide a future proof, reliable and dependable service, that will support the UK for decades to come. The upgrade to a digital line supports the next generation of voice calls – higher quality, with fewer faults and less maintenance.

Who will the 2025 BT Switch Off affect?

This new digital network is the biggest upgrade to broadband and telephone lines. Everyone using ISDN or PSTN, regardless of provider, will have their lines switched off. This means your school or business will be directly affected. 

You will therefore need to accommodate to this change to ensure your operations will continue to run smoothly.  

Transition to VoIP or SIP from ISDN & PSTN before the 2025 BT Switch Off Transition to VoIP or SIP from ISDN & PSTN before the 2025 BT Switch Off

What options do I have?

When looking to upgrade from your obsolete lines, IP Technology is what you need. IP stands for Internet Protocol and is the modern alternative to PSTN & ISDN. 


  • VoIPVoice over Internet Protocol. VoIP is the most popular modern alternative to PSTN lines and allows you to make and receive phone calls over the internet.
  • SIPSession Initiation Protocol. SIP is a highly flexible technology which enables you to send and receive multimedia data e.g. video calls and voice calls


  • FTTPFibre to the Premise. FTTP is a pure fibre connection from the exchange into your premises, offering higher broadband speeds. Full fibre services provide the capacity and speed needed for effective use of online learning tools. Full fibre services provide flexibility to future proof your organisation as demand for internet services increases.
  • SoGEA – Single order Generic Ethernet Access. SOGEA is a new standalone broadband-only product, created after Openreach decided to shut down the ISDN and PSTN network. SoGEA provides the internet connection you require within a single order and without a PSTN line, with lower install and rental costs.
The benefits of upgrading to VoIP before the 2025 BT Switch Off The benefits of upgrading to VoIP before the 2025 BT Switch Off

What are the benefits of upgrading?

Moving away from traditional lines to our newer, futureproof and cost-effective technology brings a number of benefits and widens your capabilities:

  • Reduce costs
  • Robust Connection
  • High Speeds
  • Work remotely
  • Free calls between sites
  • Keep existing numbers
  • Record your calls
  • Call Queuing
  • Email alerts & reporting
  • Auto attendant
  • Marketing messaging on-hold
  • Integration of additional solutions, including SIS / LMS
  • & Much More
  • “Strategically, we needed to prepare for the BT switch off and Tel Group ticked all the boxes. They promptly came out and gave us a very reasonable quote which enabled us not only to expand our current telephone network, but also provide a comprehensive lockdown system with CCTV and Speakers.

    I am so pleased we chose Tel Group, their advice was spot on and we now have a futureproof system in place which has also saved us money. Thank you to all the team at Tel Group – you have made our school a safer place”.

    Shirley Gascoyne, School Accountant – Ramsden Primary School
  • “We would just like to thank you for the fast and professional service we received whilst upgrading from our analogue telephone system ahead of the BT Switch Off!

    Having been a customer for several years the upgrade was seamless and the engineer, Darren, was very efficient, worked hard and answered all our questions.

    We would definitely recommend your company to other educational establishments.”

    Lesley Zetterstrom, School Business Manager – Bottlesford Infants School
  • “We decided to transfer our telephone systems over to digital from analogue ahead of the BT Switch Off and chose Tel Group as our preferred provider.

    David was extremely helpful in recommending the type of system that would provide the most cost effective solution. The implementation and installation was also very straightforward.

    The system is working really well and we are very pleased with the telecommunications set-up we have now. I would recommend Tel Group without hesitation.”

    Paula Twigg, School Business Manager – Monks Abbey Primary School
  • “We are delighted with our new phone system. The call minder system has been revolutionary for the office team.

    Since implementation, we had one morning with no internet and the telephone connectivity continued. The install was super speedy with no disruption to our working day, and the training and information provided has completely fulfilled our needs.

    My only issue…. was that we did not do this 3 years ago! We are also saving money, which is always good for a school. I couldn’t recommend Tel Group highly enough.”

    Sandra May, School Business Manager – Bushy Hill Junior School
  • “We recently transferred our telephone system to digital from analogue in preperation for the 2025 BT Switch Off.

    The transition was easy and happened almost without us knowing, keeping the same numbers so no disruption to parents.

    Tel Group are knowledgeable and friendly and respond quickly to any issues arising, they are also transparent in terms of costs.

    I would recommend them without hesitation.”

    Alison Price, School Business Manager – Ashfield Park Primary School
  • “We joined a group of schools who all purchased upgraded telephone systems from Tel Group. This process included group face to face discussions with 3 members of Tel Group staff who were all very informative.

    We found the installation process to be efficient. I have not had to contact customer service on many occasions, but when I have response time has been good.

    I have found Tel Group as a whole to be friendly, with knowledgeable staff and our new telephone system meets our requirements.”

    Office Team, Lydgate Junior and Infant School
    Enquire ahead of the 2025 BT Switch Off

    We can help plan and implement a cost effective solution for your organisation. Get in touch today to get ahead of the 2025 BT Switch Off!

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