In January 2027, the UK’s Public Switched Telephone Network (PSTN) will be permanently switched off. This legacy copper-wire system has powered national communications for decades, yet many organisations still rely on it without realising how deeply it underpins their operations.

According to recent industry data, fewer than one in five small businesses have a complete post-PSTN solution in place. Despite the deadline extension, thousands remain unprepared for the PSTN switch-off 2027, risking serious disruption to essential communication systems once the copper network is retired.

It’s Not Just About Phones

Many businesses assume the PSTN switch-off 2027 will only affect their landlines. In reality, the impact goes far beyond traditional telephony.

The PSTN currently supports a wide range of devices and systems across UK businesses, including:

• Security and fire alarms

• Door entry and intercom systems

• Payment terminals and EPOS devices

• Lift and emergency call systems

• Fax machines and modems

When the PSTN switch-off 2027 takes effect, any system still reliant on copper lines will simply stop working. For organisations that have lost visibility of what connects to their telephony infrastructure, this creates hidden risks that can cause costly downtime and compliance issues.

Why an Infrastructure Audit Is Essential

A successful transition begins with clarity. The first and most important step for any business preparing for the PSTN switch-off 2027 is to complete a full infrastructure audit.

At 1Connect, our PSTN Readiness Audit helps UK businesses uncover all communication-dependent systems, whether they’re visible desk phones or legacy devices quietly relying on analogue lines. Our approach goes beyond identification, it analyses how each component interacts with your wider IT and communication environment.

Our audit process includes:

1. Inventory Discovery – cataloguing every device and service linked to PSTN lines.

2. Dependency Mapping – identifying where systems rely on analogue connectivity.

3. Risk Assessment – prioritising critical systems that must be upgraded first.

4. Migration Planning – outlining a clear path to IP-based alternatives.

With this insight, businesses can accurately plan timelines, budgets, and technology roadmaps to ensure a smooth migration before the switch-off deadline.

From Audit to Action: Smooth Migration with 1Connect

Auditing is only the first step, the real value lies in implementing a well-planned migration strategy.

1Connect works with UK organisations to deliver fit-for-purpose IP-based communication solutions that maintain continuity and minimise disruption. Whether upgrading to hosted telephony, integrating cloud-based systems, or deploying hybrid setups that bridge analogue and digital technologies, our migration approach is flexible and scalable.

We can implement phased migrations that prioritise critical systems first, ensuring day-to-day operations remain unaffected. This structured approach not only mitigates risk but also helps businesses control costs and avoid downtime.

The Hidden Cost of Waiting

The PSTN switch-off 2027 will not include a grace period or warning phase, once copper-based systems are disconnected, they will stop working immediately.

Businesses that delay migration risk facing:

• Loss of inbound and outbound communications

• Inactive security, alarm, or door systems

• Interrupted payment or transaction processing

• Potential non-compliance with safety standards

Migration projects involving multiple vendors and dependencies can take months to complete. Starting early is essential to ensure business continuity and to avoid the rush as the 2027 deadline approaches.

Prepare Now for a Digital-Ready Future

The PSTN switch-off 2027 marks a turning point for business communications in the UK. Migrating to an IP-based environment enables organisations to unify their systems, improve reliability, and access modern features such as VoIP, SIP, and cloud-hosted telephony.

By partnering with 1Connect, you gain more than technical support, you gain a long-term migration partner who can assess, plan, and implement your transition from start to finish. We help you future-proof your communications infrastructure so your business remains connected, secure, and scalable well beyond 2027.

Next Steps

Don’t leave your migration until the last minute. Book your PSTN Readiness Audit with 1Connect today and take the first step towards a fully digital communication network.

Visit 1connectcloud.com#contact or call 01925 530 150 to schedule your consultation.