PSTN Switch-Off Deadline: What UK Businesses Must Do Before 31 January 2027

Quick answer

The deadline is 31 January 2027. From that date the analogue telephone network is switched off, and any service still running on an analogue or ISDN line stops working - phones, alarms, lifts, card terminals, door entry, the lot. As of August 2026 that leaves a little over five months. You cannot order a replacement analogue line, because Openreach stopped selling them in September 2023. If you have not started, the sequence below is the fastest honest route through it.

Most businesses have heard about the switch-off. Far fewer have worked out how much time is actually left, and almost none have counted the lines they are paying for. This guide is about the deadline itself: how long you have, what happens if you miss it, what the work involves, and the order to do it in. For the background - what the PSTN is and why it is being retired - our PSTN and ISDN switch-off explainer covers the technology. If you would rather skip to numbers, get a no-obligation quote and we will price the replacement for what you actually have.

How much time is actually left

From August 2026 that is about five and a half months, and the working time is less than that. Take out Christmas and the new year, allow for lead times on connectivity and for alarm and lift engineers who are already booking weeks ahead, and a business starting now has a comfortable but not generous runway. A business starting in November does not.

That is the real reason to move early. Not because the deadline will slip - it will not - but because the queue in front of it gets longer every month.

What actually stops working

The phones are the obvious part and the easy part. The list that catches businesses out is everything else that quietly signals over a copper pair:

• Intruder and fire alarm signalling. Needs a replacement path and a visit from your alarm company. Frequently needs re-commissioning and, for monitored systems, re-registration with the monitoring centre. See alarm systems and the switch-off.
• Lift emergency phones. Safety-critical, legally required, and required to work in a power cut - so they cannot simply move onto the office broadband. See lift emergency lines.
• Card payment terminals. Older units that dial out need replacing or reconfiguring. Usually simple, but check rather than assume - see card machines and the switch-off.
• Door entry and gate intercoms, which dial a phone to let someone in.
• Fax machines, telemetry, plant-monitoring diallers, CCTV backhaul on older installations, and the occasional franking machine.
• ISDN-fed phone systems, where the handsets are fine but the lines feeding the PBX disappear.

Our guide to devices that rely on phone lines goes through each category in more detail. The single most useful thing you can do this week is walk the building and write the list down.

What happens if you do nothing

There is no soft landing and no extension process. On 1 February 2027 the affected services stop.

In practice most businesses will not literally arrive at that morning with dead phones, because providers migrate customers ahead of the date - often onto a like-for-like replacement chosen by the provider rather than by you. That is the outcome worth avoiding, for three reasons:

1. You get what suits them. A provider-led migration typically lands you on their default product at their default price, on a fresh contract term.
2. Only the phone gets migrated. Nobody else's migration plan includes your lift or your alarm. Those remain entirely your responsibility.
3. You lose the chance to improve anything. The switch-off is the one moment in a decade when replacing your phone system is unavoidable anyway. Doing it deliberately usually costs less per month than what you are paying now and adds capability you did not have.

The financial argument reinforces the deadline. Legacy line rental has risen steeply through 2026 - our WLR price rises guide has the schedule - so every month spent waiting is a month at the highest price the old product has ever been.

The order to do it in

This is the sequence we use, and it is deliberately front-loaded with the parts that have the longest lead time.

1. Inventory the lines (this week). Get your last three bills and list every line and every charge. Then walk the building and match the physical sockets to the bills. You will find lines nobody can account for - that is normal, and clearing them out often saves real money before you have bought anything.

2. Contact the alarm and lift companies (this week). Before you decide anything about phones. These are the constraints on your timeline, they involve third parties, and their availability is finite. Ask each one what the replacement is, what it costs, and when they can attend.

3. Check what connectivity you can get. Voice will ride over your internet connection, so its quality becomes your phone service's quality. Check whether full fibre is available at your address, and if not whether SoGEA is. This also has a lead time - and if you need a leased line, a much longer one.

4. Decide what replaces the phones. For most businesses that is a hosted phone system; for some it is a simple digital line; for a few it is keeping the existing system and re-feeding it with SIP. Our guide to business landline alternatives compares them properly, and can you keep your existing phone system covers the third option.

5. Plan the number porting. Your numbers are yours and they move with you, but porting is scheduled work with a lead time of its own. Do not cease the old lines until the numbers have moved - see keeping your business landline number.

6. Sort resilience before you go live. An analogue line carried its own power; your replacement will not. Decide now what happens in a power cut: battery backup on the router and network kit, and automatic diversion of calls to mobiles. See landline resilience and failover.

7. Cut over, test, then cease. Run both in parallel briefly where you can, test every device, and only then let the old lines go.

If you want that as a printable list, our switch-off checklist is the working version.

How long each step really takes

Read that table as a whole and the real deadline becomes clearer. If you need a leased line, you needed to start already. If you need alarm and lift work, you need to book it now. If all you have is a couple of phone lines, you genuinely can do this in a month - but do it while a month is still comfortable.

What it costs

Briefly, because we cover this properly in what the PSTN switch-off costs a business: for most small businesses the ongoing cost after migrating is lower than what they were paying, because copper line rental disappears and calls are usually inclusive. The one-off costs sit in the specialist items - alarm signalling replacement, a lift unit, occasionally new handsets - and in any connectivity upgrade you need anyway.

The businesses that end up paying most are the ones that leave it late, because emergency scheduling costs more than planned work, and because a provider-led migration is negotiated entirely on the provider's terms.

The bottom line

The date is 31 January 2027 and it is not moving. From August 2026 that is around five and a half months, and the parts of the job that depend on other people's diaries are the parts that will decide whether this is routine or painful. Spend an hour this week on the inventory and two phone calls - your alarm company and your lift company - and the rest is straightforward.

If you would rather hand the whole thing over, that is what we do. Get a no-obligation quote or call 0333 006 9399 and we will tell you what you have, what it should be replaced with and what it will cost, before you commit to anything.

Getting unknown calls on a business line? Our free UK phone number checker shows which network or provider Ofcom allocated any number to, and whether the range is in service — no sign-up.