Do the UK 4G Alarm Systems have a sim card slot for cellular access?

The alarm for UK is made with 4G Europe module, in theory, as long as your local SIM card (either 2G or 4G) provides basic cellular SMS and voice call services, just like a traditional cellphone, It will work.

For Britain, by far end users reported EE, Vodafone, O2 sim cards work with their phones.