ISDN & PSTN switch-off — January 2027

Is your Edinburgh business ready for the end of traditional landlines?

BT is permanently switching off the UK's ISDN and PSTN network in January 2027. If your business still relies on traditional landlines or an older phone system, now is the time to migrate — before it becomes urgent. We make the transition to cloud-based phone systems straightforward, disruption-free and often cheaper than what you're paying today.

January 2027 is closer than it looks. Most migrations take 4–8 weeks to complete properly — don't leave it to the last minute.

✓ISDN migration specialists
✓ VoIP · Hosted PBX · SIP trunking
✓Edinburgh-based support
✓No downtime migrations
Get A QuoteMore details about the switch-off
Business woman on an IP phone in the Edinburgh office

The end of ISDN — what Edinburgh businesses need to know

In January 2027, BT will permanently switch off the UK's ISDN and PSTN network — the infrastructure that has powered traditional business landlines and phone systems for decades. When it goes, any business still relying on the old network loses service. No grace period, no temporary workaround.

The replacement technology — VoIP and cloud-based phone systems — is more flexible, more reliable and in most cases cheaper than what it replaces. The businesses that migrate early get the benefit of better technology sooner, with less stress and more choice.

If you're not sure whether your business is affected, or you want to understand exactly what the switch-off means and what you need to do, we've put together a full guide.

Read our full ISDN switch-off-guide
The modern alternative

Cloud phone systems — better than what they replace

VoIP (Voice over IP) and hosted cloud phone systems work by routing calls over your internet connection rather than the old copper phone network. For businesses, this means calls are cheaper, the system is easier to manage, and your phone system can grow or shrink with your team without expensive hardware changes.

Unlike traditional ISDN systems — which required physical lines into your premises and were expensive to scale — cloud-based systems are managed entirely online. Add a new user in minutes. Enable remote working with no extra hardware. Keep your existing numbers. Access your phone system from any device, anywhere.

The switch-off isn't just an obligation — it's an opportunity to move onto infrastructure that works better for the way modern businesses actually operate.

Flexible PBX expansion with SIP trunks
What we offer

Cloud phone solutions for every Edinburgh business

Hosred VoIP business phones in Edinburgh

Hosted VoIP

Hosted VoIP A fully cloud-based phone system — no on-site hardware, no PBX box in the cupboard, no engineer visits every time you add a new number. Calls are made and received over your broadband connection, and the whole system is managed through an online portal.

Add users, set up call routing, configure voicemail and manage everything from a browser. Works on desk phones, mobile apps and softphones — giving your team full phone system functionality whether they're in the office or working remotely.

Best for: Businesses of any size looking for a flexible, low-maintenance phone system

Hosted PBX phone systems in Edinburgh

Hosted PBX

Hosted PBX A cloud-hosted Private Branch Exchange gives your business all the features of a traditional PBX — extensions, call queues, hunt groups, auto-attendant, hold music — without the physical hardware on site. The PBX lives in the cloud and is maintained by the provider, not your IT team.

Ideal for businesses that currently run a traditional PBX and want to replicate (and improve on) that functionality in the cloud without losing the features their team depends on.

Best for: Established businesses migrating from a traditional PBX who need a like-for-like replacement with modern features

SIP Trunking

SIP Trunking

SIP Trunking If your business has a modern IP-capable PBX that you're not ready to replace, SIP trunking connects it to the internet rather than the old PSTN network. You keep your existing phone system investment and phone numbers — you just replace the ISDN lines with SIP trunks, which are cheaper and more scalable.

A practical bridge for businesses with relatively recent phone system hardware that isn't yet due for replacement.

Best for: Businesses with an existing IP-PBX looking to cut line rental costs without replacing their whole phone system

How we migrate you

From ISDN to cloud — without the disruption

A poorly planned migration can mean downtime, lost calls and frustrated staff. A well-planned one is almost invisible — your team barely notices the change, except that the system works better. Here's how we handle it.

Step 1

Audit your current setup

We start by understanding exactly what you have — which lines, which system, how calls are routed, what numbers you need to keep, and what features your team relies on. Nothing gets missed.

Step 2

Recommend the right solution

Based on your audit, we'll recommend the cloud solution that best fits your business — hosted VoIP, hosted PBX or SIP trunking — with clear pricing and a plain-English explanation of what changes and what stays the same.

Step 3

Plan the migration

We build a migration plan around your business, not ours. We'll agree a timeline that minimises disruption — including porting your existing numbers so clients always reach you on the same number.

Step 4

Handle the transition

We coordinate everything with the network and any hardware suppliers. You'll have a dedicated point of contact throughout and we'll keep you updated at every stage.

Step 5

Test, go live & support

Before anything goes live, we test thoroughly. On go-live day we're available throughout. And afterwards, we're still here — for support, changes and anything that comes up.

Why Edinburgh businesses trust us with their migration

We audit before we recommend

We won't suggest a solution until we understand exactly what you have and what you need. No guesswork, no one-size-fits-all.

Your numbers stay yours

We handle number porting as standard. Your clients call the same number they always have — they won't notice a thing.

We work to your timeline

Migrations are planned around your business operations, not ours. We'll find the window that causes least disruption.

Local support, not a helpline

After go-live you have a local Edinburgh contact, not a national support queue. If something isn't right, we fix it.

Common questions about the ISDN switch-off and VoIP migration

When exactly is the ISDN switch-off happening?

+

BT has confirmed the full switch-off of PSTN and ISDN services will be complete by January 2027. Some exchanges are being switched off earlier as part of a rolling programme — which means businesses in certain areas may lose service before the final deadline. We can check whether your exchange is in an early stop-sell or switch-off area.

What happens if I do nothing before January 2027?

+

Your traditional landlines and any ISDN-dependent systems will stop working. Calls won't connect, fax machines will be dead, and any broadband delivered over copper PSTN will go down. There is no grace period after the switch-off date.

Will I have to change my phone number?

+

No. Number porting means your existing business numbers transfer across to the new system. Your clients, suppliers and partners dial the same number they always have — the only difference is it now routes over the internet rather than the old copper network.

How long does a migration take?

+

For most SMEs, a well-planned migration takes between four and eight weeks from first conversation to go-live. Larger businesses with more complex systems or multiple sites may take longer. The earlier you start, the more calmly it can be done.

Do we need new hardware?

+

It depends on your current setup. Hosted VoIP works on existing computers and mobiles via a software app, so many businesses need no new hardware at all. If you prefer physical desk phones, modern IP handsets are available and are often included in the package. We'll advise based on what your team actually needs.

Is VoIP reliable enough for business use?

+

es — provided your broadband connection is sufficient. VoIP call quality over a good broadband connection is typically equal to or better than traditional landlines. We always check your broadband capacity as part of the migration audit and will flag any issues before committing to a solution.

Supplier of cloud phone systems and lines in Edinburgh

Don't leave your migration to the last minute

The January 2027 deadline will come around faster than most businesses expect — and the closer it gets, the more demand there will be on engineers, network capacity and migration teams. Businesses that plan ahead get a smoother transition, better pricing and more choice.

Get in touch today for a free, no-obligation assessment of your current setup and a clear recommendation on what to do next.

Not sure if you're overpaying? Get a free reviewOr call us on 0131 202 6902