Your PSTN countdown checklist

~ The steps your business needs to take in 2026 to prepare ~

When the clock stroke midnight on 1 January 2026, every small and medium-sized business in the UK should have had one resolution at the top of their list: preparing for the PSTN switch off. Here, Kristian Torode, director and co-founder of business communication and PSTN switch off specialist Crystaline offers a complete checklist of everything your business needs to review as we ring in the new year.

For decades, the Public Switched Telephone Network (PSTN) has been the backbone of UK business communications. But its time is up. BT has confirmed the official switch-off for early 2027 and the countdown is on. Despite years of warnings and planning windows, according to BT and Frontier Economics’ report on switching off the PSTN, “customers still make 40 billion minutes of fixed voice calls in the UK each year”.

The PSTN is no longer fit for purpose in today’s digital-first world. Its capabilities are too limited to meet the demands of modern businesses, and failure to act could mean more than inconvenience — think communication blackouts, payment failures, alarm breakdowns and serious reputational risks. So, what should SMEs do this year to get ready?

1.     Audit everything

Start with a full audit of all PSTN-dependent systems. The PSTN powers more than just phones, it could also be linked to alarm systems, door entry systems, card payment terminals or metering equipment.

Involve facilities, finance and operations departments to identify every dependency. Document what connects to your telephone answering support so the experience for callers remains seamless during and after the transition. This step is critical to avoid nasty surprises later.

2.     Check your internet connection

Check your internet connection. Is your current broadband reliable and strong enough to handle the increased needs of a digital phone line? When the PSTN goes, all calls will run over the internet and if your business is still on a copper-based broadband like ADSL, it’s time to upgrade to a fibre-based service.

A strong, resilient internet connection protects call quality. Without it, customers are likely to experience dropped calls or delays, which quickly undermines their confidence in you. Think of your internet as the foundation of your future communications strategy. Without it, everything else falls apart.

3.     Review hardware

Next, look at your hardware. Are your desk phones, headsets and routers VoIP-ready? Some older devices may need adapters, while others require full replacement.

This is also an opportunity to simplify your set-up. Remove unused or duplicated lines and equipment. Streamlining now will save time and money later and make your new system easier to manage.

4.     Choosing the right phone system

The choice of phone system is critical. While adapting legacy PBX systems with SIP trunking is possible, the most futureproofed option is a cloud-based unified communications (UC) platform. These systems go beyond voice calls, offering integrated tools for video conferencing, messaging, file sharing and analytics from a single app.

One solution is Vodafone Business UC with RingCentral, available through Crystaline. This platform combines Vodafone’s reliable network with RingCentral’s advanced cloud technology to deliver voice, video, messaging and collaboration in one secure, scalable system, which is ideal for hybrid working and multi-site operations. It also futureproofs your business, ensuring you can adapt as technology evolves.

5.     Train your team

Technology is only as good as the people using it. Focus training on teams who spend the most time on the phones — customer service, sales, reception and operations.

Their feedback will highlight any issues before the system goes live. Training should cover not just how to use the new system, but also how to leverage any new features that improve customer experience.

6.     Set a clear timeline

Finally, set a timeline and stick to it. Include testing, training and phased rollout stages so there’s time to learn, adjust and improve before the switch-off. With a hard deadline of 31 January 2027, the date the PSTN is switched off, it’s essential that the transition runs on time, as there is no room for manoeuvre. The transition is a major business transformation and should be treated as such.

Although moving on from the PSTN isn’t a choice, businesses should look at it positively. Moving to modern systems can unlock better customer experiences, smarter analytics and greater flexibility for teams. Audit, upgrade and test now to ensure your business stays connected and competitive in a fully digital future.

Unsure of the steps your business needs to take to avoid the issues of the PSTN switch off? Book a free consultation with Crystaline here.