- The analogue PSTN is being withdrawn under Openreach's all-IP migration, which the company expects to complete in 2027, affecting every school still on analogue lines.
- Schools commonly run alarms, lift autodiallers and signalling over the analogue line, so a voice-only swap can miss safety-critical devices.
- Department for Education connectivity standards set out the broadband, switching and cabling a school is expected to have in place.
- Ofcom requires communications providers to maintain access to 999 services when a line moves to digital voice.
- Ofcom resilience measures expect a solution that allows at least one emergency call during a power cut, which a broadband router needs battery back-up to deliver.
Schools must move off the analogue PSTN before the 2027 switch-off by auditing every line and alarm, confirming digital-ready broadband, fitting battery back-up and testing 999 access end to end.
Last reviewed: June 2026
Why schools should not leave this late
A school telephone system does far more than connect the office to parents. The same analogue infrastructure often underpins fire alarm signalling, intruder alarm autodiallers, lift emergency phones, gate and door entry intercoms, and links to a public address or tannoy system. Because these devices have quietly relied on the copper line for years, it is easy for a migration to focus on desk phones and overlook the safety-critical equipment that shares the same cabling. In a setting responsible for hundreds of children, that oversight carries real safeguarding weight.
The driver for change is fixed. Openreach is retiring the analogue Public Switched Telephone Network as part of the all-IP migration it expects to complete in 2027, after which voice runs over a broadband connection rather than the legacy line. Schools that wait to be moved risk discovering compatibility problems at the worst possible moment, with limited time and budget to react, and often during term when the disruption is hardest to absorb. Because the published timeline points to completion in 2027 rather than to a single fixed day for every site, a school cannot assume a comfortable date and should plan against the earliest realistic point at which its own exchange could migrate. Treating the switch-off as a planned project, started well ahead of the deadline, is the surest way to keep every safety-critical function working.
The systems hiding on the analogue line
The biggest risk in a school migration is the autodialler. Intruder alarms, fire panels and lift emergency phones often summon help by seizing the analogue line and dialling a monitoring centre. Some of these use older signalling that does not always pass cleanly over digital voice, so a unit that looks healthy can fail when it is genuinely needed. The failure mode is the dangerous part: the device continues to appear normal day to day and only reveals the problem at the moment it tries to make the call that matters, by which time there is no opportunity to react. Every such device should be identified, listed and tested end to end on the new service, or replaced with a digital-ready unit before the analogue line is removed.
Power is the second issue. The old copper line was powered from the exchange, so a desk phone often worked during a local power cut. A broadband router does not, and neither does anything that depends on it, unless battery back-up is fitted. Ofcom resilience measures expect a solution allowing at least one emergency call during a power cut, so a school should confirm that back-up covers the reception phone and any life-safety autodialler, and that the batteries are maintained rather than installed once and left to degrade. Lift emergency phones in particular need a reliable, always-available path to a monitoring centre, which under the lift standard BS EN 81-28 is expected to remain dependable, so the migration must preserve that link rather than quietly break it.
School PSTN switch-off migration checklist
The table below sets out the stages a school or trust should work through before depending on a migrated digital line for any safety-critical function.
| Stage | Action | Why it matters |
|---|---|---|
| 1. Audit lines | List every analogue line and device | Alarms and lifts are easily missed |
| 2. Check broadband | Confirm capacity against DfE standards | Digital voice depends on the connection |
| 3. Prioritise safety | Rank fire, intruder and lift devices | Safeguarding depends on these working |
| 4. Power back-up | Fit battery back-up for critical kit | Routers lose mains power; lines did not |
| 5. Test 999 | Verify emergency calls and autodiallers | Confirms the new path actually works |
| 6. Budget and record | Cost the project and document results | Supports trust governance and audit |
What the DfE expects of school connectivity
The Department for Education publishes connectivity and technology standards that describe the broadband, network switching and cabling a school should have in place to support modern services. Because VoIP depends entirely on a stable connection, these standards are the natural reference point when judging whether a site is ready to carry digital voice. A school whose broadband meets the DfE connectivity standard is in a far stronger position to migrate cleanly than one running on an older or congested line, where call quality and reliability could suffer.
The detail behind the standard matters for voice. Digital voice shares the same connection as everything else the school does online, from teaching platforms to administrative systems, so a line that copes with data at quiet times can still struggle when voice has to compete with peak classroom use. The connectivity standard speaks to capacity, to the network switching that carries traffic inside the building, and to structured cabling, all of which affect whether a call stays clear under load. A school assessing readiness should therefore look beyond the headline broadband speed to how the internal network and cabling will carry voice alongside data at the busiest part of the day.
Meeting the connectivity standard is necessary but not sufficient on its own. The migration also needs resilience for emergency calls, which is an Ofcom matter, and it needs the safety-critical alarms and lift phones to be confirmed compatible. Reading the DfE technology guidance alongside the Ofcom resilience and 999 access requirements gives a school the full picture: a capable connection, a reliable emergency path, and tested safety devices. Trust-level IT or estates teams are usually best placed to coordinate that across multiple sites.
Planning, funding and ownership
A school migration works best as a costed project with a named owner. Smaller maintained schools may rely on their local authority or a managed service provider, while academies and multi-academy trusts typically coordinate through a central IT or estates function. Whoever leads, the plan should sequence the work so that emergency contact and safeguarding-critical alarms are never left unavailable, and so that any incompatible device is replaced before the analogue line is withdrawn rather than afterwards.
Funding usually comes from the school or trust's own budget, since telephony and connectivity are operational costs, though schools should check current Department for Education and local authority guidance for any applicable support and factor replacement of alarm autodiallers into capital planning. The cost of an unplanned, last-minute migration tends to be higher and riskier than a phased one, so early budgeting is itself a saving. Documenting the audit, the testing and the final configuration also gives the trust the evidence it needs to show that safety-critical communications were maintained throughout the change.
Testing and assurance before go-live
The point at which a school is most exposed is the moment it relies on the new service for the first time, so testing should come before that reliance, not after. For every safety-critical device the school should confirm not just that a normal call works but that the specific function the device performs in an emergency works: that a fire panel actually reaches its monitoring centre, that a lift phone connects a trapped passenger to a person who answers, and that a 999 call from the reception phone completes and presents the correct location. Each of these should be witnessed and the result recorded against the device in the inventory, so the school holds evidence rather than an assumption.
Assurance also means rehearsing the failure conditions, because that is when these systems earn their place. A school should test that battery back-up actually holds the critical phone and autodialler up for a realistic outage by simulating loss of mains power, and should re-test after any later change to the broadband, router or alarm firmware, since a working configuration can be broken by an unrelated upgrade. Keeping a dated log of who tested what, with what result, gives leaders and governors a defensible record that emergency contact and safeguarding were preserved through the migration, and gives the next person to touch the system a clear baseline to compare against.
Frequently Asked Questions
Do schools need to migrate to VoIP?
Yes, because the analogue PSTN they rely on is being withdrawn under Openreach's all-IP migration, which the company expects to complete in 2027. After that, voice runs over a broadband connection rather than the old copper line. Schools should plan the move rather than wait to be switched, so that alarms, lifts and emergency calls keep working throughout the change.
What systems in schools use PSTN?
Beyond the main reception phones, schools often run fire alarm signalling, intruder alarm autodiallers, lift emergency phones, gate and door entry intercoms, and links to tannoy or public address systems over the analogue line. Many of these are easy to overlook because they have worked quietly for years and only reveal a problem at the moment they are needed. Each needs to be identified and tested or replaced before the line is withdrawn.
How should schools plan for PSTN switch-off?
The reliable approach is to audit every analogue line and device, confirm the broadband meets Department for Education connectivity standards, fit battery back-up for safety-critical kit and test 999 access and autodiallers end to end. Incompatible devices should be replaced before the analogue line is removed. The whole project should be costed, owned by a named lead and documented with witnessed test results.
Who pays for school VoIP migration?
Telephony and connectivity are usually operational costs met from the school or trust's own budget, with alarm autodialler replacement potentially falling into capital planning. Schools should check current Department for Education and local authority guidance for any applicable support. Budgeting early tends to cost less than a rushed, last-minute migration carried out under time pressure.
What broadband does a school need for VoIP?
VoIP depends on a stable, sufficient connection, and the Department for Education publishes connectivity and technology standards describing the broadband, switching and cabling a school should have. A site that meets those standards is better placed to carry digital voice with good call quality. Capacity should be checked under peak load before migration so that voice and data can run together reliably during the busiest part of the day.
