Why the PSTN Switch-Off Should Still Be a Priority for Businesses

BT Openreach announced a year-long delay to the Public Switched Telephone Network (PSTN) switch off, dubbed the ‘Big Switch Off’, which was due to be completed in December 2025.

The UK has been reliant on the PSTN, better known as the landline network, since the 19th Century. However, the Big Switch Off, now due in January 2027, will mark the end of an era, with landlines being replaced by digital Voice of Internet Protocol (VoIP) technology.

As a business, you’ll need to ensure that you have the right infrastructure in place to transition to a VoIP system, which relies on an internet connection to make and receive calls. Take a look at our guide to the best business VoIP providers in the UK to see what your options are.

What is the Big Switch Off?

The PSTN network has been in use since the 1800’s, but as you can imagine, today’s communication demands have increased, and speed and reliability have become the main priorities.

The old PSTN network can no longer support the demand of modern day communication, and its becoming harder and more expensive to maintain it. That’s why BT Openreach is replacing it with a digital network.

This means replacing the old copper cables that run the old PSTN network with new fibre-optic ones, a process that’s already underway.

Any phone lines and services that rely on PSTN will no longer be used once the PSTN network is switched off by BT OpenReach in January 2027.

Businesses will no longer be able to communicate over the old network and will have to switch to a network such as VoIP, which uses internet connection as opposed to the copper-based network. VoIP is also more reliable and affordable compared to the old network.

PSTN Switch Off Timeline

BT Openreach announced the PSTN switch off back in 2017. Since then, there has been a process of reducing the sale of analogue products and services, while encouraging the switch over to a digital network before January 2027.

Here’s the full timeline:

If you’re a bit lost when it comes to switching your phone line provider, check out our guide on how to change your landline provider.

Who is Impacted by the PSTN Switch Off?

Businesses and households in the UK that make and receive calls over PSTN lines are impacted by the switch off.

Additionally, businesses and households that use products connected to the ISDN (Integrated Services Digital Network), as system that uses PSTN circuits to transmit phone calls, video calls, and transmit data, will also be affected. Since both systems rely on the same infrastructure, the ISDN will be switched off along with the PSTN.

As the network is slowly turned off, both businesses and households that still use it may experience severe disruption or even a complete loss of service.

Although many have now moved over to newer, reliable technologies such as VoIP, there are a large number still using PSTN lines.

In a survey carried out by Spitfire Network Services, 72% of the UK businesses surveyed did not see the PSTN switch off as a priority. This means that when the switch off occurs these businesses may not have the right infrastructure in place to support digital tech, like VoIP.

How Will the PSTN Switch Off Affect My Business?

The degree to which the PSTN switch off will affect your business really depends on the type of tech you use. If most of the devices you rely on day-to-day use the PSTN or ISDN, be prepared to make some big changes.

Bear in mind these two points:

1. It will cost money to upgrade your office hardware, but newer tech, like VoIP, is actually much cheaper to run than PSTN lines. One of the reasons BT opted to switch off these older lines was because the upkeep was expensive and the cost was trickling down to the end user. As VoIP uses an internet connection, it’s cheaper and more reliable.
2. There may also be costs linked to training your team. Luckily, these should be one-off as your team will be able to share their learnings with new staff.

What Products Are Affected by the Switch Off?

Technology products that will stop working when the switch off happens include telephone systems that rely on the PTSN, and products that use the ISDN, instead of the internet, to transmit data, such as old fax machines, video conferencing tech, and printers.

Just remember, if a piece of tech uses the internet to transmit data, it won’t be affected. If it doesn’t use the internet, there’s a high chance it’s affected by the switch off.

How to Prepare my Business for the Big Switch Off?

To ensure a seamless transition for your business, here is our step-by-step guide to prepare for the PSTN switch off:

1. Check your kit: Check your current infrastructure to assess what currently relies on PSTN and ISDN lines. This could be phones, fax machines, and any other appliances that use a landline.
2. Contact your provider: If you’ve determined that you need to make the switch, reach out to your current provider to see if they offer VoIP. If not, you’ll need to find a new provider. You can start the search by looking through our guide to the best phone systems for small businesses.
3. Plan your switch: Once you’ve spoken to your provider and decided how much of your infrastructure will need to be replaced, plan to transition to newer technologies. Write up a timeline and a budget to ensure a smooth transition. Bear in mind that newer tech will require a sufficient internet connection.
4. Purchase new tech: Depending on your current setup, you might need purchase new phones, software, or hardware that supports VoIP and digital communication.
5. Train your team: Make sure you allocate the time and resources to train your employees on how to use the new software and hardware. Getting them up to speed quickly is essential to keeping your business running smoothly.

To simplify the switch, you can use our free quote comparison tool, and you’ll be matched with the top VoIP providers. Just give us a few details about the needs of your business, and you’ll be matched with providers who’ll contact you with obligation-free quotes. It’s that simple.

Is it Hard to Switch Telephone Systems?

We won’t beat around the bush: switching telephone systems can cause a fair amount of disruption. It’s a process that might take several weeks to complete, so to mitigate disruption, you’ll need to plan effectively.

Here’s how you can make it easier:

• Stay with the same provider if you can: You won’t necessarily need to switch providers if your current provider offers VoIP systems, so check with them first, since sticking with the same provider can make the change process easier.
• Keep your current phone numbers: If you are switching providers, try to keep your current phone numbers to avoid confusing your customers. To do this, you’ll need to request number porting from your previous provider to your new provider, which can take several weeks to complete.
• Coordinate software and hardware changes: If you need to upgrade both your hardware and software to make it compatible with VoIP, try to do change them at the same time. Your telephone systems provider can assist you in finding compatible solutions.
• Make sure you have good internet: As VoIP systems run over the internet, you’ll also need to ensure your current connection has enough bandwidth to be used for VoIP. If it’s not, you may need to consider upgrading.

As long as you plan accordingly and work with your new provider to ensure a smooth transition, you should be able to make the switch with minimal disruption.

What Happens if I Don’t Switch My Telephone Systems?

If your current telephone system uses the PSTN and you don’t switch by the January 2027cut off date, your network will no longer work and you won’t be able to use your landline phones. In fact, as BT works towards meeting this deadline, some areas have already lost network access.

Failure to switch to a newer network can mean a few things for your business, including:

• Service disruption – your business may face unexpected loss of service or disruption.
• Difficulty making and receiving calls – if your business is still on the old network, you may struggle to make or receive calls to and from users who have already switched to VoIP.
• Higher costs – one of the reasons PSTN is being cut off is because of high maintenance costs. The longer you stay with the network, the higher your costs will likely be, compared to a VoIP provider.
• Less productivity – VoIP systems have a lot more functionality when compared to landlines. Many include spam prevention, team messaging, and third-party software integrations, like a CRM system, providing your business with a seamless and efficient system.