I think for Insurance purposes that the alarm company is required to be a member of the ISIA. (Irish Security Industry Association). It may be best to check with your Insurance Company before you go down the route of using a contractor that the Insurance Co do not recognise.
Maybe Colm, but my Insurance Co insisted that the alarm was fitted by an ISIA member. It's not me making the rules, I just want my property insured.
At the time of moving home, the insurers were Chubb Insurance who clearly stipulated the terms of cover and now the current Insurers are Benchmark Insurance.