Prepare for The Big Switch-off

What is it

What is the PSTN Switch-off?

As of the 5th September 2023, BT Openreach initiated a national stop-sell of the Public Switched Telephone Network (PSTN), which was a significant milestone in the transition to newer technologies. This marked the beginning of the phase-out process, with the full PSTN switch-off scheduled for 2025.

The stop-sell means that as of the 5th September 2023, BT Openreach are no longer offering new PSTN-based services. It’s important to understand that you can continue using pre-existing legacy PSTN services until the complete switch-off in 2025. However, during this period, you will not be able to purchase any new services or modify any existing services that rely on ISDN or PSTN.

So what is the alternative?

As businesses adapt to the changing landscape, many are embracing Voice over Internet Protocol (VoIP) technology. VoIP allows users to make phone calls and transmit data over an internet connection, providing an opportunity to transition to an all-digital solution and safeguard their business for the future.

The decommissioning of PSTN lines is a once in a lifetime technological shift, however switching doesn’t have to be scary, but planning is crucial. If you have questions, Gamma is here to help.


PSTN Switch-off timeline

Key milestones.


Postcode finder

Postcode finder

The postcode finder shows the exchanges that will be going through PSTN removal and applicable dates.

Enter your postcode below to see exchange name, switch-off date and time until switch-off.


Exchange NamePostcodeSwitch Off DateTime until Switch Off

Benefits of VoIP

Benefits of VoIP

VoIP is revolutionising the way we communicate, offering cost-effective, versatile, and feature-rich solutions for businesses. As the transition away from traditional PSTN (Public Switched Telephone Network) gathers pace, VoIP is poised to play a pivotal role in shaping the future of how we communicate in a world increasingly reliant on internet connectivity. Here are some benefits of upgrading your services to VoIP:

Keeping your phone number

When transitioning from traditional landlines to VoIP, your business has the option to keep your existing phone number. Helping businesses maintain their established brand and relationships while benefiting from VoIP technology.

VoIP Cost Savings

VoIP solutions offer significantly lower rates for local, national, and international calls compared to traditional phone services. VoIP also eliminates the need for costly on-premises hardware, leading to significant cost reductions.

Great scalability and flexibility

VoIP solutions can be accessed from a variety of devices, which means you won’t be tied to a desk phone – take calls anytime, anywhere. VoIP can easily scale up or down to accommodate your business’s growth or to help with busy seasons.


Enhanced Productivity

VoIP systems are ideal for flexible working, providing consistent communication regardless of locations and offers a wide range of collaboration tools such as the advanced features to enhance productivity.

VoIP Advanced Features

VoIP offers a wide range of advanced features and capabilities beyond phone calling, including; Video Calling, File Sharing, Instant Messaging, Advanced Call Routing, Call Recording, Auto Attendant, CRM integration and more.

Reliability and Business Continuity

VoIP systems have built-in failover and business continuity options, ensuring that your communications are reliable even in the event of network disruptions.

How can Gamma help my business make the switch?

The upcoming PSTN Switch-off is a big step in the telecom industry.. Whether you’re a small business or a large enterprise, Gamma has what you need. We provide various products like SoGEA, FTTP, Mobile, Phoneline+, Horizon, and Microsoft Teams Phone for broadband and business phone solutions. These not only keep your business connected during the switch but also help future-proof your communication setup, keeping your business ahead in the digital age.

Customers should know they have a choice during the PSTN Switch-off, and they don’t need to simply accept a transition with their existing provider. There may better and cheaper alternatives available.

Business Broadband




Business Phone




Microsoft Teams Phone

PSTN Frequently Asked Questions

  • When does the PSTN Switch-off start?

    It’s already started. As of the 5th September 2023, BT Openreach initiated the first phase of the PSTN Switch-off with the national stop-sell of the Public Switched Telephone Network (PSTN). This means that BT Openreach are no longer offering new PSTN-based services. It’s important to understand that you can continue using pre-existing legacy PSTN services until the complete Switch-off in 2025. However, during this period, you will not be able to purchase any new services or modify any existing services that rely on ISDN or PSTN.

  • When is the final PSTN Switch-off happening?

    BT Openreach has announced it intends to Switch-off the traditional, analogue telephone network in 2025.

  • Why is the PSTN Switch-off happening?

    As PSTN has formed the infrastructure for UK telecommunications the 1800s, unsurprisingly it has become antiquated and costly to maintain. BT Openreach are switching off the PSTN and ISDN network to pave the way for a fully digital network which can meet the demands of the new digital era.

  • What does the PSTN Switch-off mean to my business?

    The PSTN Switch-off will affect all businesses currently operating using PSTN and ISDN services. If you fall into this category, you will need to move to the new network by 2025 to keep your communication services operational.

  • When should businesses switch their services from the PSTN?

    Businesses should start preparing for the PSTN Switch-off now, to ensure smooth transition to VoIP technology. Failing to prepare for this transition can result in disruptions to business operations.

  • What if your business has a phone and internet connection?

    If your business relies on both phone and internet services provided through the PSTN, the transition to VoIP and fibre broadband is even more crucial. Whether you need fibre broadband or phone services, Gamma can help in both instances.

  • What is VoIP?

    VoIP technology has revolutionised conventional communication, surpassing the capabilities of PSTN and ISDN services with more cost-effective and advanced features. VoIP leverages an existing internet connection for phone calls. Initially, this solution appeared risky, as it heavily relied on the quality of the internet connection to ensure stable calls.

    Today, most broadband services provide sufficient speed to mitigate concerns related to call quality. VoIP telephony is a simpler choice than it may seem, demanding far less hardware than PSTN and ISDN services.

    VoIP presents a versatile option that can be utilised across a range of devices, spanning from traditional desk phones to mobile devices, tablets, and computers.

  • Will the PSTN Switch-off affect a businesses internet connection?

    If you are still using ADSL, ADSL2+* or have a FTTC internet connection that runs over an analogue PSTN telephone line then you will need to upgrade your internet connection.

    If you have already upgraded to SoGEA, have a full fibre FTTP connection or if your business uses a dedicated leased line then you should not be impacted by the PSTN Switch-off but we would recommend checking in any event.

    *Available until March 2024 – UK ADSL Stop Sell – only applicable to areas where SoGEA / FTTP is unavailable.

  • How will the 2025 Switch-off impact devices connected to the PSTN?

    All technology that uses the PSTN network will be impacted. The transition will affect services such as security and fire alarms, telecare devices, and retail payment terminals and any other devices that rely on the PSTN. These services depend on certain PSTN features not entirely replicated in VoIP platforms, potentially impacting residential, commercial, and public sector users. Manufacturers have utilised BT’s testing facility to adapt their equipment to the new All IP network, and a list of those who have completed testing can be found.

    If you are unsure about how a device in your business might be affected, we recommend you contact the equipment supplier or device manufacturer to find out whether it will remain functional on a digital phone line. If you are buying a new alarm or device, you should check it is compatible with VoIP services.

  • Will the PSTN Switch-off affect emergency 999 calls?

    Emergency services that rely on PSTN connections will be impacted by the switch off. Telecoms companies are required by Ofcom to take all necessary measures to ensure uninterrupted access to emergency organisations for their customers, including in the event of a power cut. For most customers, telecoms companies recommend using a mobile phone as a backup in case of a power cut. If you live somewhere where there’s no signal, in the UK, national roaming is enabled in order to make emergency calls. This means you can use any mobile phone network to contact the emergency services, even if you are not a customer. You may see the message ‘Emergency calls only’ displayed on your handset if this is the case.

Why Morph?

Morph, created over four decades ago by Peter Lord and David Sproxton, is one of multi award-winning animation studio Aardman’s pioneering and simplest masterpieces. This clay character, recognised for his slapstick comedy prowess and gobbledygook language, employs alternative methods to convey messages, aptly reflecting the essence of the Big Switch-off campaign.

His appeal bridges multiple generations and his ability to simplify and bring humour to the everyday ensures that he cuts through the noise and capture audience’s attention. We believe that raising awareness of this significant change within UK businesses is essential and are hoping that the partnership of Gamma and Morph will draw attention to the Big Switch-off which to date has gone largely unheralded.


Learn more about the PSTN Switch-off

We have lots of resources, including podcasts, blogs, and articles, designed to assist you in navigating the upcoming PSTN switch off and staying informed about this industry-changing transition.

Ready to make the switch?

Whether you are a new or current customer, a partner, or potential partner, Gamma is here to assist you with the PSTN Switch-off. Get in touch with us today to explore your options, address your questions, and ensure a smooth transition into the digital era.
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