The BT ISDN switch off is a significant development set to change the communication landscape across the UK. As we inch closer to the switch-off deadline, it becomes increasingly crucial for businesses like yours to understand and prepare for the changes ahead.

The switch-off signals the retirement of the Public Switched Telephone Network (PSTN) and Integrated Services Digital Network (ISDN), sometimes referred to as ‘analogue’ lines. These are the traditional landline phonelines that plug into the back of your telephone. As a result, these telephony services, including fixed lines, will no longer be available – a big problem for many businesses!

Openreach (owned by BT) is the primary provider of these solutions and will shift its focus to developing the fibre network. This is set to render PSTN and ISDN products obsolete, meaning profound implications for businesses with a heavy reliance on these services.

Understanding the BT 2027 Switch Off

The PSTN is a legacy network that’s formed the backbone of telephone services for decades. It supports various providers, including Wholesale Line Rental (WLR) and both forms of ISDN (ISDN2 and ISDN30). However, due to the evolution of broadband services and the need for a high-availability fibre network, Openreach has made the decision to withdraw the network.

What does it mean?

Essentially, it means that traditional telephony services will no longer be available. This includes the WLR and ISDN services we’ve mentioned above, as well as Asymmetric Digital Subscriber Line (ADSL) Broadband and Fibre to the Cabinet (FTTC) Broadband. ADSL is the most common type of broadband internet, that comes in through your phoneline, while FTTC runs along fibre optic cables from the phone exchange to the green roadside cabinets. Openreach won’t be providing replacements for these products and services, which means you need to act now to switch to alternative solutions so your telephony services still work.

When will it happen?

The withdrawal has actually already begun. A full ‘Stop Sell’ of new supply WLR, started in September 2023, meaning that sales of traditional phoneline packages and deals have been gradually phasing out. The remaining timeline has been clear, too, with BT analogue switch off deadline of January 2027 set in stone.

Business Implications of the BT ISDN Switch-Off

The switch-off is going to represent a significant shift in the UK’s communications landscape, bringing with it a host of implications for businesses like yours.

The switch-off will necessitate investment in new technologies such as Voice Over Internet Protocol (VoIP) , which allows you to make voice calls using a broadband internet connection and fibre broadband services (which you may already have at home). While this may present challenges for certain businesses, it also brings with it a wealth of exciting opportunities.


What are the challenges?

  • New Technology: One of the main challenges faced by businesses will be the need to transition away from traditional telephony services. For many companies, traditional telephony systems have been in use for many years. This means employees have become accustomed to the systems, and workplace structures may depend on them.
  • Infrastructure Requirements: New alternatives to traditional methods often rely on robust and reliable internet connections. Some organisations, particularly small businesses, may find adapting to this challenging for their existing connection strength so a new network may be required.
  • Compatibility Issues: Similarly, the BT ISDN switch-off could bring compatibility issues. Pre-existing hardware or software might not be properly optimised to work with new, unfamiliar systems.

What are the Opportunities?

  • Cost Effectiveness: Innovative VoIP systems significantly reduce communication costs compared to traditional landlines. This is because the need to pay for expensive, dedicated lines or separate mobile phones is removed.
  • Flexibility and Agility: Modern telephony solutions are far more adaptable than their traditional counterparts. They offer the agility that businesses need in today’s fast-paced environment, allowing staff to use the communication system remotely and flexibly, accessing data and networks wherever they need it.
  • Reliability: Hosted phone systems or cloud-based VoIP systems are often more reliable than traditional systems. Statistically, they’re less likely to experience downtime and can offer a more consistent quality of service.
  • Future-Proof: Traditional phone systems are on their way out, and investing in modern telephony is a vital step towards future-proofing your business. As digital tech evolves, so too will the capabilities of these systems, offering businesses the opportunity to stay competitive.
A digital phone labelled 'VoIP' in front of a screwed up piece of paper reading 'ISDN'

Preparing for the BT 2027 Switch-Off

To overcome the challenges and maximise the opportunities, businesses need to prepare for the change proactively. The steps taken now will impact how effectively your company can adapt to and thrive in a post-ISDN world.

Assess your current situation

It’s important to conduct a thorough audit of your current communication systems. This includes identifying all PSTN and ISD lines and services within your operations, as well as lines, ADSL broadband, and FTTC broadband connections. By understanding your current usage, you can better assess your future requirements, negating some of the teething difficulties of adapting to a new system.

Consider the available technologies

Investigate and explore the possibilities offered by the various alternative technologies on the market. Get to grips with the ins and outs of VoIP and fibre broadband to better inform your decision when the deadline arrives. Remember, some of these innovations might necessitate upgraded hardware or infrastructure, so cross-referencing new tech with your existing capabilities is crucial.

Get organised in advance

Plan your migration timeline well ahead of the January 2027 deadline. The process of switching to new technologies can take time, particularly for larger businesses. To complete it with minimal disruption to your operations, it’s vital to plan your transition structure in advance.

Choose the right provider for you

Perhaps the most important step in preparing for the BT analogue switch off is selecting the right service provider. It’s essential to choose an operator who can offer a competitive price, minimal hassle and robust and transparent customer care.

Get Ready for the BT Analogue Switch-off With Maincoms

As the BT ISDN switch-off looms, your business may be facing uncertainties. But worry not, we at Maincoms are here to guide you through this notable transition. We’ve gathered the best products, suppliers and networks to deliver future-ready solutions tailored for you.

Our ethos is all about transparency – no hidden terms, conditions or charges. With us, what you see is exactly what you get. Our exceptional customer reviews a testament to our dedication to you and your business, as evidenced by our glowing reviews.

Get in touch with us today on 0333 358 3000 or through our contact page. Let us help your business sail smoothly into the new era of communication.