Auditing an IoT estate for UK mobile-network retirement

Network position as at September 2026, based on Ofcom's guidance updated on 1 September 2026, is that UK 3G networks have been switched off and 2G retirement is being planned on operator-specific timetables. The Ofcom advice for IoT and third-party device suppliers also highlights that roaming arrangements can change the impact on devices. Check the relevant provider's current information before setting a migration deadline; a general industry horizon is not a guarantee for an individual installation.

Build the inventory from more than the SIM bill. Reconcile procurement records, maintenance contracts, application logs and physical asset lists. Include equipment that sends data rarely or only when something goes wrong. A dormant unit can look harmless in a usage report while still carrying an important operational function.

For every asset, record location, purpose, owner, device model, modem variant, firmware, SIM supplier and current observed radio technology. Separate evidence from assumptions. A sticker saying 4G does not establish which modem is fitted, how it is configured or whether every required service uses that technology.

Netavo supplies multi-network IoT connectivity on its own mobile core. The migration question is whether the intended replacement device and service support the required operation at the actual location.

Ask what each device does besides sending telemetry. It may use SMS for configuration, a voice call for an operational function or a legacy connection mode during recovery. A successful data test does not validate those additional functions. Identify the application protocol and the receiving system, including any supplier-managed platform that must accept a replacement unit.

For equipment with voice requirements, obtain explicit confirmation of the supported voice method from the device and connectivity suppliers. Do not infer voice support from LTE data capability. Similarly, LTE-M and NB-IoT are specific technologies, not interchangeable labels for any newer IoT modem. The device, service and available radio network need to align.

Netavo's IoT SIMs support LTE-M and NB-IoT for low-power devices. They do not provide VoLTE, so a device that needs a voice path after the older networks close needs a different arrangement, such as a line on a hosted voice platform.

Record roaming dependencies separately from the names of networks that appear in a scan. Ask the service supplier which access remains permitted for that SIM and technology, and how changes are communicated. Equipment may depend on an arrangement that is not obvious from its billing brand. Keep the supplier's response with the asset record and give it a review date.

For utilities and other distributed estates, include physical access constraints. A unit on a remote site, behind a locked enclosure or dependent on a specialist maintenance visit cannot be treated like a spare router on an office desk.

Give each asset a decision, owner and acceptance test. Some may need a modem or complete device replacement; others may need supplier-approved firmware or configuration changes. Do not assume that a SIM swap changes the hardware's supported technologies. Obtain a documented compatibility position before scheduling the visit or buying replacements in volume.

Prioritise by consequence of failure, known dependency and difficulty of access. A rarely used device may deserve earlier attention than a busy one if its failure would be harder to detect or recover from. Group similar equipment for planning, but keep exceptions visible. Different modem variants inside the same enclosure can require different work.

Pilot the replacement on representative sites before committing the estate. Prove application delivery, any required voice or messaging function, remote configuration, restart recovery and behaviour when coverage is poor. Check that the monitoring platform recognises the new device and that support teams can distinguish a genuine fault from planned work.

Plan the physical change with the service owner. Record how the existing function will be maintained during the visit, what evidence allows acceptance and what happens if the replacement fails its checks. Retire the old connection only when the responsible owner confirms the new service is operating as required.

Keep the inventory alive after the programme. Record the replacement hardware, firmware, test results and next review date. Network retirement exposes gaps in ownership that otherwise persist for years; a maintained asset record makes the next technology change a planned maintenance task rather than another discovery exercise.