The BT Landline Switchover and Gigabit Britain: A UK Business Guide

The BT Landline Switchover: simple guide for UK businesses

What’s changing, which services are affected, and how to get your business ready — in plain English.

  • Deadline: PSTN and ISDN switch off completes by January 2027.
  • All-IP future: Calls will run over your internet connection.
  • Action: Audit phones, alarms, lifts, fax, payment terminals, and other copper-based devices.
  • Outcome: Faster, more reliable services on modern fibre networks.

The Vision of Gigabit Britain

Gigabit Britain is the government and telecoms industry’s ambition to provide a full-fibre, gigabit-capable network to at least 85% of UK premises by 2027, with the ultimate goal of full nationwide coverage.

“Gigabit-capable” means broadband speeds of 1Gbps (1,000 Mbps) or higher — a big step up from copper-based connections. For businesses, this means:

  • Flawless remote work: Smooth video calls and cloud apps without lag.
  • Enhanced productivity: Faster file transfers and handling of large data.
  • Improved resilience: Fibre is more reliable and less affected by the environment.
  • Future-proofing: Ready for IoT, AI and data-heavy tools.

This is a proactive move away from aging copper towards faster, more sustainable fibre infrastructure.

Why the PSTN and ISDN Switch Offs are Happening

The BT landline switchover is central to Gigabit Britain. The traditional Public Switched Telephone Network (PSTN) and the Integrated Services Digital Network (ISDN) are now obsolete.

BT Openreach has set a firm deadline: the PSTN and ISDN switch off completes by January 2027. After this date, traditional analogue landlines will cease to function. All voice calls will be delivered digitally over an IP (Internet Protocol) network using your internet connection.

This is a mandatory migration. A “stop-sell” has already been in place in many areas since September 2023, meaning new PSTN/ISDN orders are no longer available.

Services Impacted by the BT Landline Switchover

The switchover affects more than just office phones. Many systems that rely on copper lines will be impacted. Audit your setup to identify everything connected.

The table below summarises what’s affected and the recommended modern alternatives.

Current Service Impact of Switch Off Recommended Replacement
Traditional landline phones (PSTN) Will no longer function after January 2027. VoIP (Voice over IP) or SIP-based telephony.
ISDN lines for business calls Complete withdrawal by January 2027. SIP trunks or hosted VoIP solutions.
ADSL broadband Dependent on copper lines, will be withdrawn alongside PSTN. Full-fibre broadband (FTTP) or a dedicated leased line.
Alarm systems, lifts, and door entry systems Analogue connections may fail, causing critical safety systems to stop working. Digital, IP-enabled alternatives.
Fax machines Likely to become unreliable and eventually stop working. Online fax or secure digital document transfer services.
Payment terminals (card machines) Devices using analogue lines will stop working. IP-enabled or mobile data-enabled payment devices.

Why the Switchover is a Gateway to Gigabit Britain

Moving all communications onto one IP-based fibre network makes things simpler and more efficient.

Key benefits include:

  • Consolidated infrastructure: One modern network for voice, data, and video — lower maintenance and complexity.
  • Enhanced flexibility: Cloud services (hosted phone, collaboration) work seamlessly.
  • Improved resilience: Fibre is durable and reliable, even in bad weather.
  • Cost savings: Bundle voice and data on a single high-speed connection.

The switch off isn’t just retiring old tech — it’s enabling the faster, flexible, resilient networks behind Gigabit Britain.

Preparing Your Business for the Change

The deadline is approaching, so preparing early avoids disruption. Use this simple plan:

  1. Conduct a thorough audit: Identify everything that uses a landline — phones, fax, alarms, fire panels, CCTV, lifts, and more.
  2. Choose the right solution: For phones, consider Hosted VoIP or SIP Trunks. For connectivity, pick a business-grade fibre service or a dedicated leased line depending on needs.
  3. Upgrade your connectivity: A stable broadband line is essential for VoIP quality. Daisy offers a range of business-grade broadband solutions tailored to modern organisations.
  4. Partner with an expert: Migrating your communications can be complex. Working with an experienced provider like Daisy ensures a smooth transition, from audit to migration.

Ready to prepare your business for the BT landline switchover and embrace Gigabit Britain? Get in touch with a Connect & Grid expert today.

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