UK PSTN Switch-Off 2027. Is Your Business Ready?

The UK Is Switching Off Traditional Phone Lines in 2027. Here's What Your Business Needs to Know.

If your business still uses a traditional landline, you need to read this. BT Openreach is switching off the UK's old copper telephone network,known as the PSTN (Public Switched Telephone Network) and ISDN, by January 2027. When that happens, every business and household still relying on a traditional phone line will lose their service overnight.

This isn't a distant concern. With the deadline less than 1 year away, businesses that haven't already made the switch to VoIP (Voice over Internet Protocol) need to start planning now.

 
What Is the PSTN Switch-Off?
The PSTN is the traditional copper wire telephone network that has been the backbone of UK communication for over a century. BT Openreach announced that this ageing infrastructure will be permanently decommissioned by January 2027, replaced entirely by digital, internet-based communication.

If your business uses any of the following, you are affected:

Traditional landline phones
ISDN lines for voice or data
Fax machines connected to phone lines
Alarm systems or door entry systems connected to the phone network
Payment terminals connected via phone line
Broadband delivered over copper phone lines (ADSL)
 
What Is VoIP and Why Is It the Replacement?
VoIP stands for Voice over Internet Protocol. Instead of sending voice calls over copper wires, VoIP converts your voice into digital data and sends it over your internet connection, the same way an email or a video call works.

Modern VoIP systems are more flexible, more feature-rich, and often significantly cheaper than traditional phone systems. They allow your team to make and receive calls from any device: desk phone, laptop, or mobile, from anywhere with an internet connection.

For businesses that have already made the switch, VoIP has become an essential part of how they operate. For those that haven't, the 2027 deadline is the nudge they need.

 
What Happens If You Don't Switch in Time?
Simply put, your phones stop working. When BT Openreach decommissions the PSTN, any device still connected to the old copper network will lose service completely. There will be no grace period and no fallback option.

Beyond losing phone service, businesses that leave the switch too late also risk:

Rushed migrations: Last-minute moves increase the risk of errors, downtime, and data loss. The closer to the deadline, the more pressure there is on engineers and providers, meaning longer wait times and less flexibility.

Disruption to other systems: Many businesses don't realise how many systems beyond their phones rely on the PSTN. Alarm systems, door entry, CCTV, and payment terminals connected to old phone lines will all be affected.

Missed cost savings: Businesses that switch early benefit from lower call costs, reduced line rental, and the ability to scale their phone system up or down without expensive hardware changes.

 
The Benefits of Switching to VoIP Now
Lower costs: VoIP calls are significantly cheaper than traditional landline calls, particularly for international calls. There are no line rental fees, and adding new users is simply a matter of software rather than physical installation.

Work from anywhere: Your team can make and receive business calls from their laptop or mobile using the same number, whether they're in the office, at home, or with a client. This is particularly valuable for businesses with hybrid or remote workers.

More features, more flexibility Modern VoIP systems come with features that traditional phone systems simply can't match:  call recording, auto-attendant, call routing, voicemail to email, video calling, and detailed call analytics.

Easy to scale Adding a new team member to a traditional phone system means new hardware and an engineer visit. With VoIP, it takes minutes. The same applies to removing users, changing numbers, or setting up a new office location.

One provider for phones and IT When your phone system runs over your internet connection, it makes sense to have your IT provider manage it. At Blackgate Tech, we manage VoIP alongside your broader IT infrastructure, meaning fewer suppliers, fewer invoices, and a single point of contact when something needs attention.

 
What to Do Before the 2027 Deadline

1. Audit your current phone setup Start by identifying every device and system in your business that connects to the phone network. This includes phones, fax machines, alarms, door entry systems, and payment terminals.

2. Check your broadband connection VoIP requires a reliable, fast internet connection. If your broadband is currently delivered over copper ADSL, you'll need to upgrade to fibre before or alongside your VoIP migration.

3. Choose a VoIP provider There are many VoIP providers in the market. Look for one that offers reliable uptime, good support, and a system that integrates with the way your business already works.

4. Plan your migration carefully A VoIP migration doesn't have to mean downtime. With the right planning, you can switch over seamlessly without your team or your customers noticing any disruption.

5. Don't leave it to the last minute The closer to January 2027 the deadline gets, the busier engineers and providers will be. Businesses that plan early get more choice, better pricing, and a smoother transition.

 
How Blackgate Tech Can Help

At Blackgate Tech, we help small and medium businesses across London plan and execute their move to VoIP before the 2027 deadline. We handle everything from auditing your current setup and recommending the right system, to managing the full migration and providing ongoing support once you're live.

We also manage your VoIP system as part of your broader IT support, so your phones, your network, and your devices are all looked after by one team, with one monthly cost and one number to call when you need help.