The PSTN Switch-Off and Alarm Signalling: What Buyers Check

The analogue telephone network that has carried alarm signals for decades is being retired. Openreach has confirmed 31 January 2027 as the deadline for switching off the analogue Public Switched Telephone Network, a date delayed once from December 2025. Legacy intruder alarms, fire systems, and CCTV that still signal over copper telephone lines will stop reporting after migration, and they tend to fail quietly rather than with an obvious alarm.

For owners of monitored alarm and alarm receiving centre businesses, this is both a risk and an opportunity, and it has become a question that buyers ask early in due diligence. Understanding your own position before you go to market is well worth the effort.

What the Switch-Off Actually Changes

The move is to an all-IP network, where voice and data run over internet protocol rather than the old copper telephone lines. Any signalling path that relied on a dial-up connection or an analogue line to reach a monitoring centre needs to move to internet or cellular signalling, ideally on a dual-path basis so that a single failure does not leave a site unmonitored. The relevant transmission standard, EN 50136, and the monitoring centre standard, EN 50518, set out what a compliant, resilient signalling and monitoring arrangement looks like.

In practice, this means a large installed base of accounts up and down the country will need to be visited, assessed, and upgraded before the deadline. For a business with a book of monitored accounts, that is a known and dated piece of work, and a buyer will want to know how much of it is still outstanding.

Why This Matters to a Buyer

Recurring monitoring revenue is the single most valuable element of an electronic security business. Monitoring and alarm receiving centre books are frequently valued on a multiple of monthly recurring revenue, commonly in the region of thirty to forty-five times, rather than on EBITDA alone. That makes the integrity of the monitored base a central question in any acquisition.

A book of accounts still signalling over copper is a liability hiding inside that recurring revenue. It carries the risk of silent failures, customer loss, and the cost of a rushed migration close to the deadline. A buyer will look at what proportion of the monitored base is already on IP or dual-path signalling, what remains on legacy lines, and whether there is a credible plan and the engineering capacity to complete the work in time.

From Compliance Deadline to Recurring Revenue

The more constructive way to see the switch-off is as a structural reason to upgrade. Migrating an account from a copper line to a modern signalling device converts a one-off compliance task into an upgraded, often higher-value, recurring signalling contract. A business that has already moved its base across, or is part-way through with a clear schedule, protects its recurring monitoring revenue and presents a much cleaner acquisition than one that has left the work untouched.

This is one of the clearer examples of how a regulatory change can strengthen rather than threaten a well-run security business. The owners who get ahead of it turn a deadline into additional contracted income and a more defensible valuation.

What to Document Before You Sell

If you are thinking about a sale in the next couple of years, it is worth preparing a clear view of your signalling position now: the proportion of monitored accounts by signalling type, the migration plan and timeline, your alarm receiving centre connectivity, and the level of dual-path coverage across the base. Presenting this proactively removes a question mark that would otherwise sit over the recurring revenue, which is exactly the income a buyer is paying the most for. Our notes on recurring monitoring revenue and on preparing your security business for sale go into more detail.

If you run a monitored alarm or alarm receiving centre business and want to understand how your signalling position affects your value to a buyer, that is a sensible conversation to have, in confidence and with no obligation.