The PSTN switch-off: what partners need to know for 2026

The move away from the old Public Switched Telephone Network (PSTN) is entering its final year. Openreach has confirmed that the national switch-off will go ahead in January, stating that there will be no more delays. That means any of your customers still using PSTN-based services will need to transition to digital alternatives before the deadline.

With significant industry-wide price increases landing throughout 2026, now is the time to review your customer base get any customers still on legacy services migrated.

You’ll receive formal notification of these changes soon, but in the meantime, we want to give you a heads up and remind you that we’re here to work through this with you and help you protect your customers from avoidable disruption.

A quick reminder for your customers: what WLR and ISDN actually are

These traditional copper-based services support everything from standard voice calls to alarms, lift lines and payment terminals. As the UK moves fully to digital IP networks, these older technologies are being retired.

Many end-users won’t be aware of what’s running in the background, so a simple explanation can make a big difference when you start conversations with them.

What’s changing in 2026?

Openreach has announced a series of price increases for any remaining WLR and ISDN services. These apply across the entire industry, not just Zen.(Price increases measured against December 2025 figures).

• April 2026: +20%
• July 2026: +60%
• December 2026: Final uplift bringing the total to +100%

These increases reflect the rising cost of maintaining the legacy network in its final year. Moving customers to all-IP services avoids these increases completely. It’s also a good incentive for users to move off legacy technology as soon as possible.

What happens if your customers do nothing?

At the January 2027 switch-off, any remaining PSTN-based services will be moved by Openreach to a basic fallback called Emergency Voice Access (EVAC).

EVAC supports emergency voice calls only. It won’t support:

• Broadband
• Alarm lines
• Lift lines
• Card machines and payment terminals
• Telemetry or monitoring systems

It also offers fewer features than today’s PSTN services. It’s a last-resort safety net – not something your customers can rely on.

Helping them move now is the simplest way to avoid disruption.

What partners should do next

Most migrations are simple when planned early. To get started:

• Review which of your customers still rely on WLR or ISDN.
• Urge your end users to speak with the suppliers of alarms or specialist equipment to confirm what digital alternatives they support.
• Work with your Zen account manager or partner experience manager to plan migrations and choose the right IP-based replacements.

We’ll support you through the entire process, including identifying affected lines, selecting the right products and managing the transition smoothly.

Why acting now is the best move for you and your customers

Upgrading ahead of the deadline keeps things steady for your customers and avoids unnecessary costs, surprise outages and last-minute pressure.

A planned transition brings:

Cost avoidance

Switching to digital options now removes the impact of the steep price rises across 2026.

A single, futureproof move

All-IP is the future of the UK’s phone and broadband services. Moving now gives your customers a clean, one-time upgrade rather than multiple forced changes later.

Better reliability and performance

VoIP services offer clearer audio, fewer faults and a more resilient service.

Modern features customers will value

Depending on what they need, you can offer a range of voice and connectivity services – from CloudComms to leased lines – helping to futureproof their businesses for years to come.

Better for the environment

All-IP services use less power and reduce the carbon impact tied to maintaining the legacy network.

We’re here to support you

The final year of PSTN is a major industry milestone, and it’s an opportunity to strengthen the service you offer your customers. We’ll help you plan, communicate and deliver a smooth move to digital.

If you’d like help reviewing your customer base or planning migrations, get in touch with your account manager or partner experience manager, or contact us.