SIA licence
An SIA licence is a licence issued by the UK's Security Industry Authority, required to work in certain private security roles such as door supervision, CCTV public space surveillance and close protection. It is held by individuals, not by companies, though a guarding company will typically only deploy licensed staff to a licensable role.
Not every security-adjacent role needs one. In-house security staff and roles that do not fall under the licensable activities the SIA has defined can operate without a licence, which is part of why buyers and job listings are specific about which roles are licensed.
For a buyer comparing guarding or monitoring companies, staff holding a current SIA licence for the role they are doing is a baseline regulatory fact worth asking about directly, rather than assuming.
Camzify is software, not a guarding company, and does not hold or require an SIA licence itself. The licence applies to the individuals a guarding company, monitoring company or ARC employs in licensable roles, which can include the people who respond to what Camzify's rounds and detections raise.