What is the PSTN switch-off?
The UK’s copper phone network closes on 31 January 2027
The Public Switched Telephone Network (PSTN) is the UK’s copper wire telephone network that has carried business phone calls for over a century. On 31 January 2027, Openreach will permanently close it down – and the deadline will not be extended.
What most businesses don’t realise is that the switch-off affects far more than just your desk phones. It also affects your broadband if you’re on ADSL or FTTC, and potentially your alarm system, door entry, lift emergency line and card payment terminals if any of those connect via a traditional phone line.
Blowfish Technology has already migrated over 50 North West businesses from legacy PSTN and ISDN to modern hosted VoIP and fibre broadband – handling phones, broadband and everything in between from a single point of contact.
North West businesses migrated
Point of contact for everything
Hard switch-off deadline
Typical migration timeline
Important: Over half a million UK business lines remain on legacy copper infrastructure. Those businesses now face rising line rental costs and a hard service cut-off in January 2027. The time to act is now – not Q4 2026, when every provider in the country will be overwhelmed with last-minute migrations.
What it affects
It’s not just your phones
Work through this list and flag anything that applies to your business. Each item needs to be reviewed and migrated before January 2027.
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Phone systems
Any business telephone system connected via PSTN lines or ISDN (ISDN2 or ISDN30) will stop working. This includes on-site PBX systems that use ISDN trunks – the lines feeding the system are what matters, not the handsets.
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Broadband (ADSL and FTTC)
ADSL runs entirely over copper. FTTC uses fibre to the street cabinet but copper to your premises – and depends on the PSTN. Both need to move to FTTP, SoGEA or a leased line before the switch-off.
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Alarm & security systems
Many intruder alarms and fire alarm monitoring systems communicate via a dedicated analogue line. This is one of the most commonly overlooked dependencies – and one of the first things we check in a PSTN audit.
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Door entry & lift lines
Building entry systems and lift emergency phones are often wired to a traditional phone line. These are safety-critical and legally regulated – they need to be identified and migrated carefully.
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Card payment terminals
Older PDQ terminals sometimes use an analogue fallback line. Most modern terminals connect via broadband or mobile data, but if yours was installed more than five years ago it is worth confirming with your payment provider.
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Fax lines
Any dedicated fax line runs over the PSTN. If your business still uses fax – common in legal, medical and accountancy – this needs a replacement solution. Internet fax services handle this cleanly without disrupting workflows.
The replacements
What replaces the PSTN?
For most North West businesses the migration involves two things – a new phone system and an upgraded broadband connection. Blowfish handles both from a single point of contact, with no disruption to your working day.
For your phone system: Hosted VoIP
A hosted VoIP system delivers your business calls over your broadband connection rather than copper lines. There is no on-site hardware to maintain. Your team uses the same numbers on desk phones, laptops and mobiles – and you keep your existing phone numbers, with us managing the porting process.
Blowfish supplies and fully manages Horizon by Gamma, one of the UK’s most widely deployed hosted VoIP platforms. It includes call recording, hunt groups, voicemail to email, auto-attendant and the Webex soft client so your team can make and receive calls from any device, anywhere. Learn more about our telephone systems.
For your broadband: FTTP, SoGEA, leased line or Starlink
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FTTP
Full fibre to your premises. Speeds to 1Gbps, far better reliability than copper. The natural replacement for most FTTC customers across Lancashire and Greater Manchester.
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SoGEA
Broadband without a traditional phone line. A cost-effective bridge where full fibre rollout is still in progress.
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Leased lines
Dedicated, uncontended, symmetric bandwidth with a guaranteed uptime SLA. The gold standard for business-critical operations.
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Starlink for Business
For rural North West businesses where full fibre isn’t available, or as resilient failover for any site.
Migration process
How a Blowfish PSTN migration works
We have handled over 50 PSTN and ISDN migrations for North West businesses – from single-site operations with a handful of lines through to multi-site businesses with complex call routing.
Audit
We review your current phone lines, broadband connections and any connected devices – alarms, entry systems, payment terminals. Flags all hidden dependencies before they become a problem.
Recommendation
We recommend the right hosted VoIP platform and broadband solution for your business. Options explained in plain English, with pricing, and a clear proposal with no hidden costs.
Migration
We manage the entire migration – broadband installation, VoIP configuration, number porting and device setup. Most migrations complete with no disruption to your working day. Number porting typically takes 10-15 working days.
Ongoing management
Your new phone system and broadband are fully managed by Blowfish. One number to call for everything – faults, changes, additions, renewals. No more dealing with multiple providers.
Why Blowfish
Why choose Blowfish for your PSTN migration?
Questions
Frequently asked questions
Will the January 2027 PSTN deadline be extended again? +
Openreach has stated clearly that the January 2027 deadline is fixed and will not be extended further. The deadline was already pushed back once from December 2025. Businesses should plan on the basis that the switch-off will happen on schedule.
Can we keep our existing phone numbers? +
Yes. Your existing numbers port across to the new VoIP system. We manage the entire porting process – it typically takes 10-15 working days and your phones remain operational throughout. There is no need to change stationery, your website or marketing materials.
Does the PSTN switch-off affect FTTC broadband? +
Yes. FTTC broadband uses fibre to the street cabinet but relies on the copper network for the final section to your premises. It is a PSTN-dependent service and will be affected by the switch-off. You need to migrate to FTTP, SoGEA or a leased line. We can check what is available at your address and recommend the right option.
What happens to our alarm system? +
If your alarm communicates via a dedicated analogue phone line, that line will stop working in January 2027. We flag this during our initial audit so nothing gets missed. You will need to arrange an alternative communication path with your alarm provider.
How long does a PSTN migration take? +
For a typical North West SME, migration from ISDN to hosted VoIP and from FTTC to FTTP takes between two and four weeks from instruction to go-live. The main variable is broadband installation lead times, which depend on your location. Starting now gives you comfortable headroom before the deadline.
Will VoIP work if our internet goes down? +
We configure failover routing so that if your main broadband connection fails, calls are automatically redirected to mobile numbers or another location. We can also add a 4G/5G or Starlink backup connection to keep your phones and everything else online.
Can you handle multi-site businesses? +
Yes. We have migrated multi-site North West businesses with different connectivity requirements at each location. Hosted VoIP makes multi-site particularly straightforward – your entire phone system runs from a single cloud platform, with seamless transfers between locations and a single monthly bill.
Why act now rather than wait until 2026? +
By Q3 and Q4 2026, installation lead times will lengthen and pricing pressure will increase as millions of businesses all try to migrate at the same time. Openreach has also begun increasing wholesale line rental charges on legacy copper products throughout 2026 – moving early stops that price creep immediately. Businesses that migrate now get a considered, unhurried process.
Ready to plan your PSTN migration?
Talk to Blowfish Technology. We’ll audit your current setup, tell you exactly what needs to change, and give you a clear plan and quote with no obligation.