Business device audit checklist
Why you need to audit your devices
Most businesses know they have phones. Fewer realise how many other devices quietly use the phone line in the background: card terminals, alarm communicators, lift emergency phones, door entry systems, fire alarm diallers, franking machines.
When the analogue phone network is switched off, any device that dials out or receives calls over that line may stop working. Some failures are obvious (a phone that goes silent). Others are invisible until something goes wrong (an alarm that no longer reaches the monitoring centre).
This checklist helps you find everything before the switch catches you off guard. DESNZ guidance recommends that organisations audit their phone-line-dependent systems as part of migration planning.
How to use this checklist
Work through your premises area by area. For each device you find, record:
- What it is (make and model if visible)
- How it connects (phone socket, ISDN, broadband, mobile/SIM)
- Who supplies or maintains it (company name, contract reference)
- Whether it has been confirmed as compatible with digital voice
If you manage multiple sites, repeat for each location. Print this page and take it with you as you walk the building.
Reception and front desk
- Desk phones and cordless handsets. Note make and model. Corded phones plugged into the wall socket will usually work through the adaptor your provider supplies. Phones connected via a PBX system may need that system to be upgraded first.
- Door entry buzzer or intercom. If the door release is wired to the phone line (visitor presses a button, it rings a phone inside, you press a key to unlock), this uses the PSTN. See our door entry and intercoms guide.
- Fax machine. If there is a fax machine at reception, it will be affected. See our fax machines and analogue devices guide.
Back office
- Fax machine. Check printer rooms and admin areas. Some multifunction printers have a fax module connected to the phone line.
- Franking machine. Check whether it downloads postage rates via the phone line or via broadband/Wi-Fi. The label on the back or the supplier can confirm.
- EPOS (electronic point-of-sale) system. If your till or stock system dials out over the phone line, it is affected. Most modern EPOS uses broadband, but older systems may not. See our EPOS and phone-line devices guide.
Security
- Burglar alarm communicator. Open the alarm panel (usually a metal box in a cupboard or utility area). Follow the cables. If one goes to a phone socket, the alarm reports to the monitoring centre via the phone line. Contact your alarm company.
- CCTV uplink. Some CCTV systems send alerts or footage to a monitoring centre via the phone line. Check with your CCTV installer.
- Panic or hold-up alarm. Retail premises sometimes have a panic button that dials a monitoring centre. Check whether this uses the phone line.
For more detail, see our security and fire alarms guide and monitoring and alarm signalling guide.
Fire safety
- Fire alarm communicator. If your fire alarm system reports activations to a monitoring centre, check how it communicates. A phone-line communicator is at risk. This is a compliance matter. Contact your fire alarm maintenance company.
- Sprinkler or suppression system monitor. Some suppression systems have a communicator that dials out on activation. Check with your maintenance provider.
Building services
- Lift emergency phone. Passenger lifts are required to have an emergency communication device. Many use the phone line. If yours does, the lift company needs to install an alternative (typically a 4G communicator). See our lifts and emergency lines guide.
- Gate or barrier entry system. Intercom systems at vehicle gates or barriers sometimes use the phone line to call a number inside the building. Check the connection.
- Building management system (BMS). Some older BMS setups use a phone line for remote access or fault reporting. Check with your facilities management provider.
Payment
- Card payment terminals (PDQ machines). If the terminal dials out over the phone line to process transactions (you can hear it), it will stop working. Contact your payment provider for a broadband or 4G replacement. Most providers have been issuing replacements already. See our payment terminals and business lines guide.
Next steps
- Compile your list. Write down every device you found, its connection type, and the supplier or installer responsible for it.
- Contact each supplier. Ask whether the device is compatible with digital voice. If not, ask about the upgrade or replacement path, the cost, and the lead time.
- Prioritise by risk. A card machine that fails costs you revenue. An alarm communicator that fails could mean you are uninsured or non-compliant. A lift phone that fails is a safety obligation. Start with the highest-consequence items.
- Run the device risk checker. Use our device risk checker to get a quick assessment of each device type.
- Test after migration. Once your line has been switched, test every device on your list. Do not assume they all survived the change.