- Openreach is retiring the analogue PSTN as part of the all-IP migration scheduled to complete in 2027, after which traditional analogue voice lines will no longer be sold or maintained.
- Some door entry systems use a telephone-line link so a flat handset rings over an external line rather than dedicated wiring, and that link depends on the PSTN.
- Many traditional door entry systems use their own dedicated risers and handsets and are unaffected, so the first task is to establish which type a building has.
- Ofcom requires providers to give notice before withdrawing analogue services and to support customers through the migration.
- In a block of flats, responsibility for communal equipment usually rests with the freeholder or managing agent under the terms of the lease, not the individual leaseholder.
A door entry system that routes its audio over an analogue phone line will stop working at the PSTN switch-off, so the freeholder or managing agent should migrate it to an IP or mobile-network solution.
Last reviewed: June 2026
How door entry systems use the phone network
Door entry systems come in two broad families, and only one of them is exposed to the switch-off. Traditional systems use dedicated audio or video wiring that runs from the entrance panel up through the building to a handset in each flat. These systems do not touch the public phone network at all, so the retirement of the PSTN does not affect them directly. The other family routes calls from the entrance panel over a telephone line so that pressing a flat's button rings a number rather than a dedicated handset.
This telephone-line approach became popular because it avoids running new cable through an existing building. The entrance panel behaves like an autodialler: when a visitor presses a button, the panel dials a stored number, which might be a handset in the flat or even a resident's mobile, and opens a voice path so the resident can speak to the caller and release the door. Because that path travels over the analogue PSTN, it is precisely the kind of service the switch-off withdraws.
What the switch-off means for residents
If a building's entrance panel depends on an analogue line, the symptom of the switch-off is simple: visitors press the button and nothing happens, or the resident's handset never rings. The audio link is broken because the dial tone the panel relies on has gone. As with other PSTN-dependent equipment, the failure can be hidden during everyday checks if the line has been migrated to a router-based service, because a power cut can then take down the broadband and silence the panel at the worst moment.
The practical consequence is that deliveries, carers, and visitors can no longer be admitted remotely, and in some buildings the door release itself is tied to the same circuit. For sheltered or supported housing this overlaps with telecare considerations, where the warden call or alarm pull-cord system may share infrastructure that also needs migrating. The safest assumption is that any system involving a phone line should be surveyed before the local exchange is migrated.
Door entry system PSTN migration options
Replacing or upgrading a door entry system does not always mean ripping out the entrance panel. The right option depends on whether the building has structured cabling, reliable mobile signal at the door, and a managed broadband connection. The table below sets out the common routes.
| Option | How it works | Wiring needed | Considerations |
|---|---|---|---|
| GSM/4G entry panel | SIM card dials the resident over mobile | None beyond the panel | Needs good signal at the entrance; calls can ring a mobile |
| IP/network entry panel | Audio and video over the building network | Data cabling to the panel | Supports app-based answering; needs powered network |
| VoIP/SIP retrofit | Existing panel kept, line replaced by VoIP | Minimal; reuses panel | Only as reliable as the broadband path behind it |
| Dedicated-wiring system | Self-contained handsets on building risers | New riser cabling | Independent of any external network |
A mobile-based panel is often the least disruptive retrofit for a small block because it does not require new cabling and can ring residents' existing phones. A self-contained, dedicated-wiring system removes any dependence on an external network but is a larger capital project. The choice should weigh the building's size, the budget, and how reliably each option behaves during a power cut.
Who is responsible in a block of flats
In a leasehold block, the door entry system is communal equipment. Responsibility for its upkeep and replacement normally falls to the freeholder or the managing agent acting on their behalf, with the cost recovered from leaseholders through the service charge in line with the lease. Individual leaseholders are rarely entitled to alter the communal system themselves, so the migration has to be organised centrally rather than flat by flat.
Managing agents should audit the entrance panel and any associated lines, confirm whether the system is PSTN-dependent, and obtain quotations for a compliant replacement well ahead of the exchange migration. Where the building also has telecare or warden call equipment, those systems should be reviewed at the same time so a single coordinated upgrade avoids repeated disruption. Residents who are unsure should ask the managing agent to confirm what migration plan is in place.
Planning a coordinated upgrade
Because the switch-off touches several pieces of equipment in a typical block, the most efficient approach is to treat the door entry system as part of a wider building survey rather than an isolated fix. A managing agent who books a contractor purely to look at the entrance panel may find later that the same exposure applies to lift emergency phones, fire alarm signalling, and any monitored intruder alarm that also dials out over an analogue line. Surveying all of these together avoids paying for repeated visits and means the building can be brought across to the new network in a single planned programme rather than in a series of emergency call-outs after services have already failed.
Timing matters as much as technology. Communications providers give notice before withdrawing analogue services, and Openreach has published the all-IP migration timeline that the industry is working towards, with the programme scheduled to complete in 2027. Acting early, while there is still a working line to test against, lets a contractor install and prove the replacement before the old service is ceased. Leaving the work until the line has already gone removes that safety net and can leave a building with a non-functioning entrance system, blocked deliveries, and frustrated residents while a replacement is sourced and fitted under pressure.
Frequently Asked Questions
Will my door entry system work after PSTN switch-off?
It depends on how the system is built. Self-contained systems with dedicated wiring and handsets are unaffected. Systems that route calls over a telephone line will stop working once that analogue line is withdrawn, so those need to be migrated to an IP or mobile-network solution before the local exchange is switched.
How does a PSTN door entry system work?
The entrance panel acts like an autodialler. When a visitor presses a button, the panel dials a stored number over the telephone line and opens a voice path so the resident can speak to the caller and release the door. Because that path travels over the analogue PSTN, it is exposed to the switch-off.
What replaces PSTN for door entry systems?
Options include GSM or 4G panels that dial residents over the mobile network, IP and network-based panels that use the building data network, VoIP retrofits that keep an existing panel, and fully self-contained dedicated-wiring systems. Mobile-based panels are common for smaller blocks because they avoid new cabling.
Who is responsible for upgrading a communal door entry system?
In a leasehold block the freeholder or managing agent is normally responsible for communal equipment, with costs recovered through the service charge under the lease. Individual leaseholders usually cannot alter the system themselves, so the migration must be arranged centrally rather than flat by flat.
How much does it cost to upgrade a door entry system?
Cost varies widely with the size of the block, the chosen technology, and whether new cabling is required. A mobile retrofit of an existing panel is usually the least expensive route, while a full dedicated-wiring system is a larger capital project. Managing agents should obtain itemised quotations before committing.
