The Big Switch Off — PSTN & ISDN

The UK copper phone network is being switched off in January 2027, and you can no longer buy or change the services running on it. Here is what that means and what to do about it.

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Stop Sell Has Already Happened. The Switch-Off Is Next.

Last updated 11 August 2026

BT has stopped selling and supporting PSTN connections, including Wholesale Line Rental. The UK-wide stop sell means WLR single and multi lines and ISDN2/ISDN30 can no longer be purchased at all, and in exchanges where FTTP is available the same applies to new ADSL, FTTC and G.Fast orders.

Existing lines keep working until the switch-off in January 2027, but they are frozen: you cannot order new ones, modify what you have, add services to a line, or move a line within the same exchange area. Businesses are already hitting this in practice, and leaving it late means fewer options, more disruption and higher cost.

The part of this that catches people out is rarely the phones. Every business planning for the switch off counts its handsets; very few count the analogue lines doing something else — the lift emergency phone, the intruder alarm dialler, the fire panel, the door entry system, the care alarm, the barrier at a yard. Those sit on the same network and the same timetable, and they take longest to resolve because the answer usually involves a third party rather than a telecoms supplier.

Which of your lines are affected?

Almost every business has more analogue lines than it thinks, because most of them have nothing to do with phones. Walk the building and look for these — the ones at the bottom of the list are the ones that get missed.

Analogue phone lines, including any single line kept for a back office or a reception desk
ISDN2 and ISDN30 circuits feeding an on-premise phone system
The fax line, if one still exists
Card and PDQ terminals that dial out over a phone line
Intruder and fire alarm diallers, and anything monitored by a third party
Lift emergency phones and disabled refuge intercoms
Door entry systems and gate intercoms
Any line nobody can account for — these are usually still being billed

What Your Options Are

Move to Cloud Telephony

Replace the lines entirely with a hosted platform such as Evonex, running over a fibre connection. No on-premise hardware to replace again later.

Keep Your PBX, Move to SIP

If your phone system is IP-capable and you want to keep it, SIP trunks deliver the same calls over your internet connection with full number porting.

Migrate Your Special Lines

Lift lines, alarm lines and analogue lines underpinning other services can be migrated, though usually onto a different tariff. These are the ones that catch businesses out, so we audit them first.

Who we work with

We are independent of any single network or vendor, so the recommendation follows the requirement.

Telephony platforms

Hosted, on-premise or Microsoft Teams — the right answer depends on the building, not on what we prefer to sell.

Network and vendor names and logos are the trademarks of their respective owners, shown to describe the services SCG Solutions supplies.

Services Affected by Stop Sell

WLR single lines and multi lines
ISDN2 and ISDN30
ADSL (SMPF)
FTTC and G.Fast
Analogue lines behind lifts, alarms and door entry
Any line move within the same exchange area

The Big Switch Off — PSTN & ISDN — Common Questions

When exactly is the PSTN switch-off?

January 2027 is when the existing lines stop working, but the date that matters to most businesses has already passed: stop sell is in force nationally, so copper services cannot be bought, moved or modified now. In practice that means a routine office move or an extra line has already become a migration project rather than a simple order.

What does stop sell actually prevent?

You cannot order new copper services, modify an existing one, add a service to a line, or move a line within the same exchange area. Existing lines carry on working until the switch-off itself, so nothing stops overnight — but the ability to change anything has already gone, which is what turns an ordinary request into a project.

My lift and alarm lines are analogue — what happens to those?

They can be migrated, but usually onto a different tariff, and they need checking individually because something else depends on them. These are the ones most often missed, so they are the first thing we audit.

What happens if I do nothing?

The lines stop working in January 2027, and long before that you have already lost the ability to change anything — so a simple office move or an extra line becomes a full migration under time pressure. The other risk is engineer availability: every business in the country faces the same deadline, and the alarm, lift and fire companies get busier the closer it gets.

Has the switch-off date changed?

Yes, once. It was originally December 2025 and was pushed back to January 2027, largely because of the number of vulnerable customers and special services — telecare, alarms, lift lines — still running on analogue. Treat the new date as firm: stop sell is already in force nationally, so the practical deadline for anything that needs changing has effectively passed already.

Will my phone number change?

No. Numbers port across to the replacement service, so anything printed on your signage, vehicles, stationery and website stays correct. This is the single most common worry and it is the easiest one to settle — you keep the number, you change what carries it.

What about our card machine and the fax line?

Both are on the list of things that quietly depend on an analogue line. A card terminal dialling out over a phone line needs moving to an IP or mobile-based equivalent, and a fax line usually gets replaced by email-to-fax rather than rebuilt. Neither is difficult, but neither survives the switch-off untouched, and both tend to be discovered late.

Do I have to move to a cloud phone system?

No. Cloud telephony is the most common answer because it removes the on-site hardware entirely, but SIP trunking into an existing phone system is often the cheaper route if that system is modern enough to take it, and an on-premise IP system is still a legitimate choice. What is not an option is staying on copper.

How long does a migration take?

For a small single site, often a morning. For a multi-site business with call routing, recording obligations and special lines, plan on weeks rather than days — mostly for surveying and scheduling rather than the work itself. The constraint as 2027 approaches is engineer availability, not complexity, which is why early is cheaper than late.

Find Out What You Are Running

Most businesses do not know which of their lines are affected until something needs changing. We will audit what you have and tell you what has to move, and by when.

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