PSTN Switch Off 2027: What UK Businesses Should Do Now

UK landlines are moving away from the Public Switched Telephone Network (PSTN) and ISDN. For most customers, the upgrade is expected to be complete by January 2027, with services moving to internet based alternatives such as VoIP and digital voice. This is an industry led change, not a government programme, but the impact on businesses is very real. Source: https://www.gov.uk/guidance/uk-transition-from-analogue-to-digital-landlines

If you are a UK business that still relies on legacy phone lines for calls, payments, alarms, or building systems, the safest move is to treat 2027 like a hard operational deadline. The best outcome is not only staying connected, but coming out of the migration with a call experience that is faster, more trackable, and easier to automate.

What the PSTN switch off means in plain English

The PSTN is the old analogue network that powers traditional landline calling. It is being retired and replaced with digital services delivered over an internet connection, for example Voice over Internet Protocol. ISDN, a related digital service used for telephony, is also being switched off. Source: https://www.gov.uk/guidance/moving-landlines-to-digital-technologies

For many businesses, the migration can look simple on the surface. You may plug a handset into a router instead of a wall socket, or move to a hosted phone system. But the complexity usually hides in the devices you forgot were using the phone line.

The real business risk is not the handset

Government guidance is clear that communications providers will not know what non voice devices are connected to your line. That means it is on you to find them and plan upgrades. Source: https://www.gov.uk/guidance/uk-transition-from-analogue-to-digital-landlines

Common examples include:

Building and security alarms
Lift and elevator alarms
Door entry and intercom systems
Card payment terminals
Legacy fax lines and specialist equipment

If any of these systems fail during the transition, the impact is not only inconvenience. It can be compliance risk, revenue loss, and safety risk.

A practical checklist for UK businesses

Use this as a starting point for a simple internal audit.

1. Identify what you pay for today

Check your telecom bills and contracts
Confirm whether you have PSTN, ISDN, or other legacy services
List every location, every line, and every number that matters

2. Inventory every device that touches the phone line

Walk the building and ask a blunt question: what breaks if the old line disappears.

Alarm panels and monitoring equipment
Payment terminals and backup dial lines
Lift emergency phones
Reception and front desk phones
Any analogue adapters or legacy PBX equipment

3. Plan for power cuts

With analogue landlines, some basic corded phones could work during a local power cut because the line carried a low voltage feed. Digital voice does not work the same way. Handsets and routers rely on local power, so you need a resilience plan. Source: https://www.gov.uk/guidance/uk-transition-from-analogue-to-digital-landlines

At minimum:

Decide what must keep working during an outage
Put battery backup on critical networking and voice equipment
Ensure your team knows what the fallback is, for example a mobile phone plan

Migration options and what to ask vendors

There are multiple ways to move to digital voice. The right choice depends on your scale, your support requirements, and whether you need call centre functionality.

Questions to ask any provider:

What happens to emergency calling during a power cut
How do you handle number porting and multi site routing
Can you support call recording and retention policies
What integrations exist for CRM, helpdesk, and analytics

The opportunity most businesses miss

Many teams treat the PSTN migration as a technical project. They move calls to VoIP and stop there.

But inbound calls are one of the highest value channels for many businesses. Calls carry buying intent, urgency, and context. If you are not capturing that information, you are losing money quietly.

The modern call stack is not only a phone line. It is routing, documentation, automation, and measurement.

A product idea worth building during the switch

This is where Crudloop comes in.

Crudloop can be the AI layer that sits on top of your new digital voice setup, turning calls into actionable work.

What that looks like in practice:

Smart routing so the right person answers based on intent, team, or customer type
Automatic transcription and call summaries for every important conversation
Follow up tasks created automatically, so deals and support issues do not get dropped
Clean call logs that sync into your CRM or helpdesk, so the whole team has context
Reporting that shows which calls convert, which get missed, and where revenue is leaking

The result is not only continuity after PSTN retirement. It is a measurable improvement in customer experience and sales operations.

A simple 30 60 90 day action plan

Days 1 to 30

Complete your device audit
Confirm your migration timeline with your communications provider
Identify critical lines and critical call flows

Days 31 to 60

Choose a digital voice approach and test number porting
Validate every attached device in a controlled test
Implement power resilience for your critical setup

Days 61 to 90

Roll out company wide and train staff on the new call process
Add automation and call documentation
Measure missed calls, response times, and conversion outcomes

Closing

The UK PSTN and ISDN retirement is a deadline, but it is also a reset. If you treat it as a chance to modernise how your business handles calls, you can end up with a system that is more reliable, more trackable, and more profitable.

If you want help designing and building a modern inbound voice layer on top of your migration, book a call with Crudloop.