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PSTN switch off 2025: Why you should migrate to VoIP

BT Openreach announced the end of PSTN and ISDN back in 2015. The telecommunications service provider began shutting down networks in 2020 and will stop taking new orders starting 2023. By December 2025, PSTN circuits will be shut off completely.

Before we dive into the details of the PSTN switch off, here’s a summary of the terms we’ll be using to help you understand the situation better:

Know your jargons

PSTN – stands for Public Switched Telephone Network, the old circuit-switched network that powers traditional telephone lines and cables.

ISDN – stands for Integrated Services Digital Network. It’s a circuit-switched telephone network just like PSTN. The difference is that ISDN transmits voice and data via digital instead of analogue lines. It also provides better voice quality.

Traditional Telephony – A traditional or legacy telephony system runs on premise-based physical boxes connected by wires. Both PSTN and ISDN systems are considered traditional because they still rely on cables.

VoIP or Cloud Telephony – Cloud business phone systems, or VoIP, route calls through the internet, eliminating the need for telephone boxes and cables and other on-premises hardware.

What’s happening in the PSTN switch off?

BT Openreach will be switching off all PSTN services, both for businesses and homes. The phaseout will include ISDN networks since these also run on traditional telephone lines.

Everything else that uses your old phone network will be affected by the switch-off. This includes door entry systems, CCTVs, fax machines, PSTN alarm systems and even electronic point-of-sale (EPOS) machines. Manufacturers are already working on solutions to replace these products so you can retain the same functions post-switch off.

Why is Openreach doing this?

BT Openreach acknowledges that the nature of telecommunications has changed drastically in the past decade. ISDN networks can no longer support the speed, scalability and method of communications that businesses need today.

With that, Openreach has decided to stop investing any more money and labour into a technology that can’t fulfil the needs of the modern business landscape. Additionally, the firm will cease its PSTN services to make companies migrate to telecommunications solutions that enable them to grow at the pace they want.

BT Openreach is actively endorsing all-digital communications as replacements for legacy telephone systems. These solutions include cloud telephony, hosted PBX and other internet-based communication systems.

What does the switch off mean for your business?

About 2.4 million businesses in the UK still operate on PSTN or ISDN, most of which are small and medium enterprises. Some larger organisations have also yet to make the switch. Roughly 33 per cent of large corporations still rely on analogue for a portion of their communications processes.

If you’re one of the businesses still using landline telephones and fax machines, the switch off will dramatically impact your operations. You’ll need to figure out how this situation will change how your staff communicates with clients, customers, partners and vendors and how you’ll cope with that change.

You may be thinking, ‘The switch-off is years away. Why do I have to worry about it now?’ You need to start planning your strategy for the switch off as early as now because there are many factors to consider. Will you need to get rid of your telephones and purchase new equipment? Is your internet connection fast enough to support cloud telephony?

Ultimately, you shouldn’t wait until 2025 to migrate your phone networks. We’ve detailed everything you need to learn digital communication systems to help you prepare for your VoIP switch.

What is VoIP?

Also referred to as internet telephony, IP telephony and voice over broadband, VoIP phone systems convert voice into digital data and send it over an internet connection. VoIP lets you make phone calls with all the features of traditional telephony systems, such as caller ID, voicemail and call forwarding. You can also keep your landline number in case someone with a VoIP-enabled phone system calls you.

Additionally, VoIP software integrates well with desktop computers to use as ‘softphones.’ This means you can make calls using your computer, as long as it has audio input/output capabilities.

What are the benefits of VoIP?

1. Lower Costs

Calls are cheaper on VoIP compared to traditional phone lines. Landline calls are expensive because there are too many users and not enough phone lines to accommodate the demand. On the other hand, routing your calls through the internet means you don’t have to contend with other people for data carriage.

A lower cost per call is a huge advantage if you often contact someone abroad. VoIP offers cheap international calls so you can talk to your foreign clients without worrying about racking up a huge phone bill. Plus, you’ll have a flat-rate monthly fee, so there will be no surprises when you get your bill.

2. Higher Scalability

One of the biggest advantages of VoIP is scalability, making it an ideal solution for businesses eyeing expansion. You won’t have to purchase additional hardware or extensions to scale your operations since your phone network is digital.

You’ll have the bandwidth you need to accommodate surges during peak seasons. Opening a new branch also becomes easier since your communications will be unified in one digital network.

3. Supports Multitasking

Some VoIP systems offer plenty of functions beyond the ability to make audio calls. You can hold conference calls and send videos, photos and documents in the middle of the conversation. VoIP also lets you collaborate on calendars, share presentations and desktops and send instant messages.

VoIP systems with these features are also known as Unified Communications (UC), which are enterprise solutions that integrate all your communications functions into one platform for seamless and easy use.

4. Increasing Accessibility

Cloud-based VoIP services let you make calls from anywhere using any device. All you have to do is add your device to the cloud network and route your calls. If you’re unavailable at the moment, you can direct your incoming calls to someone else or have the voicemails sent to your email.

This level of accessibility is especially helpful if you’re managing a mobile workforce. They can keep in touch with their team, access files and send their output no matter where they are, so they’ll stay productive regardless of their location.

How to setup VoIP

Another advantage of VoIP is that it’s easy to set up. Follow these steps to go digital:

1. Test your network and internet connection

The performance of your VoIP system depends largely on your network connection. Many of the complaints and problems with VoIP happen due to an unstable or slow internet connection, so make sure yours is fast enough.

Most internet service providers now offer gigabit speeds in their business plans. Gigabit is much faster than megabit, with one Gbps equivalent to 1,000 Mbps. You can look into these internet plans to ensure that your connection can support all VoIP capabilities.

Other than speed, you also need to look at the stability of your internet connectivity. Opt for wired internet connection like cable or fibre because these are more stable than wireless or microwave.

We recommend getting a Fibre to the Cabinet (FTTC) internet service if you’re implementing a unified communications strategy. FTTC provides a superfast broadband connection over fibre optic cable to support bandwidth-heavy functions like video calls.

But if you’re using a VoIP phone system minus UC, a Single Order Generic Ethernet Access or SOGEA connection should be enough. SOGEA offers the same speeds as FTTC, but the rates are cheaper because it doesn’t have a landline setup.

Be sure to check your connectivity’s packet loss and jitter since these are the two metrics that indicate your upload and download speeds.

2. Find a VoIP provider

Switching to VoIP gives you plenty of opportunities to upgrade your internal and external communications. Look for a VoIP service provider that offers functionalities that make communication easier and more seamless for your company. You can tell them some of the miscommunication issues you often experience, and they’ll recommend features for you to add.

You can get call analytics and CRM integration, for instance. These tools are incredibly advantageous if you use your customer contact centre for data and insight gathering.

Below are other VoIP features to consider:

• Interactive Voice Response
• Advanced Call Routing
• Auto Attendant
• Low-Cost International Calls

3. Set up your desk phone and headset

Once you have your provider, it’s time to complete your office VoIP setup. This would depend on the equipment you currently have. Although VoIP technology itself doesn’t need any special hardware to run, you need some devices to ensure high call quality.

For instance, you might want to invest in high-quality webcams, headsets and microphones if you’re using your desktop for video conferences.

However, if you’re working remotely, you can use your smartphone or laptop to make voice calls through VoIP.

4. Test your new VoIP lines

Test your VoIP connection once everything is set up. Pay attention to these when making calls:

• Audio quality – Is the audio clear and crisp? Is there any static or breaking up?
• Latency – Is there a delay between when you say something and when the other person hears it?
• Connection stability – Does the call suddenly drop? Some firewall settings can cause calls to drop after 11 minutes, so be sure to test the call for at least 15 minutes.

Don’t forget to test your lines when there’s a lot of network activity. Network congestion may affect call quality and cause issues like choppy or delayed audio. If that’s the case, you need a stronger internet connection.


The bottom line is that you need to start planning for the PSTN switch off as early as possible to make sure you’re making the best decisions for the company. This event isn’t only a chance to upgrade your phone system; it’s also an opportunity to make your entire business communications more seamless and efficient.

There are plenty of modern technologies you can leverage to catapult your business growth, from cloud-based phone systems to unified communications. Ask a telecommunications expert for advice on what solution would best suit your business needs and goals.

If you want to learn more about migrating to VoIP and cloud-based phone systems, visit the Gamma blog. For enquiries about business communications solutions, fill out our contact form.