What questions should I ask an alarm monitoring company before signing?

Ask which Alarm Receiving Centre will monitor the system and its certification, whether the company is on the NSI or SSAIB register under the exact legal entity on your quote, whether police response is achievable at your address, what the total cost is broken down by element, and what the notice and renewal terms are.

A specific list worth taking to a survey:

Which legal entity am I contracting with, and what is its company number? Are you on the NSI or SSAIB register under that entity, and for which scope? Which ARC will monitor the system, and what is its BS EN 50518 certification? Can I get police response at this address, and will you make the URN application?

What grade are you designing to, and why that grade? What signalling path or paths, and what happens — and how quickly — if a path fails? Is the communicator sold or rented, and is it locked to your ARC?

What is the total first-year cost, itemised into monitoring, maintenance, hardware and police fees? What is the contract term, the notice period, and the renewal behaviour? How can the price rise during the term? What is the early-termination charge?

If a salesperson is reluctant to put any of these in writing, that is your answer.