PSTN Switchoff 2027: What UK Businesses Need to Know

What is the PSTN/ISDN Switchoff?

The Public Switched Telephone Network (PSTN) is the traditional copper-wire telephone system that has powered the UK for over a century. ISDN (Integrated Services Digital Network) was the digital upgrade introduced in the late 20th century.

As internet-based routing has evolved, these legacy lines have become obsolete, expensive to maintain, and prone to faults. Because of this, BT Group announced that Openreach will permanently retire this legacy copper infrastructure. Every voice service in the UK must migrate to modern IP (Internet Protocol) networks. You can read the full official regulatory stance on the Ofcom Moving to VoIP Guide.

How Does This Affect My Business?

Once legacy lines are switched off in your area, any devices connected to them will cease to function. This does not just apply to desk phones and switchboards; traditional copper lines are quietly powering a massive amount of everyday business infrastructure, including:

• Card Payment Machines: Older desktop PDQ and card terminals that plug directly into a wall socket.
• Alarms & Security: Intruder and fire alarms connected directly to remote monitoring services.
• Emergency Lift Lines: The backup emergency communication phones inside elevators.
• Legacy Fax Machines: Traditional fax setups that rely on analogue dialling tones.

The Hidden Realities of Going Digital

Switching to a digital network involves a bit more than just swapping out your desk phones. To ensure your business isn't caught off guard, keep these technical and local factors in mind:

The “Power Outage” Reality

Traditional copper telephone lines carry their own low-voltage electrical current, meaning an old analogue phone works even during a power cut. Digital VoIP lines, however, rely entirely on your building's local power and internet connection. If the electricity goes down, your phones and connected alarms will too, unless you have a backup plan—such as an Uninterruptible Power Supply (UPS) or a router with a 4G/5G cellular backup.

Local “Stop Sells” Are Already Active

While January 2027 is the ultimate national deadline, the process is happening in rolling regional phases. Openreach has already implemented a national “Stop Sell” on analogue infrastructure across the vast majority of UK exchanges. This means businesses can no longer purchase new traditional lines, add features, or make major changes to existing copper-based contracts. Your existing setup is essentially frozen until you migrate. You can check the ongoing status of the network upgrades directly on the official Openreach Call Upgrading Dashboard.

Understanding the New Standard (SOGEA)

When you move away from traditional infrastructure, your broadband delivery changes too. You will likely transition to SOGEA (Single Order Generic Ethernet Access). This is a modern, data-only connection that strips out the legacy voice frequency entirely, giving you a dedicated internet pipe without the unnecessary cost of an underlying analogue phone line.

The True Cost of Waiting: Openreach Price Penalties

If you are planning to wait until the final months of 2026 to make the switch, it will cost you. To push businesses off the aging infrastructure, Openreach and major UK providers are introducing steep, phased price hikes on remaining legacy line rentals:

• April 2026: A 20% price increase on traditional line rentals.
• July 2026: An additional 40% increase on top of the base rate.
• October 2026: Another 40% hike, effectively doubling the maintenance cost of holding onto old lines before the final cutoff.

What Should You Do Next?

Preparation is key. Switching early prevents last-minute service blackouts and shields your business from the upcoming price penalties.

Transitioning to a cloud-based VoIP (Voice over Internet Protocol) solution like RingPilot keeps your lines running seamlessly. A managed transition allows you to:

• Preserve Your Numbers: Safely port your existing, established local area business numbers to the cloud without downtime.
• Work Safely Anywhere: Answer your business line via a mobile app, laptop, or desktop IP phone whether you are on-site or in the office.
• Unlock Smart Features: Access modern tools built to capture revenue, such as automated missed-call SMS notifications and AI-driven call summaries.

Don't wait for the copper network to go dark or for line fees to double. Contact us today to audit your current setup and ensure a smooth, managed migration to digital.