We now offer the 3Day Door Supervisor Level 2 course. The Door Supervisor Licence allows holders to work in the private security industry in a variety of roles. The licence is issued by the Security Industry Authority (SIA) and is valid for 3 years. SIA Door Supervisor Licence holders allow individuals to work in pubs, events, bars, shops, shopping malls, office buildings and many more. A Door Supervisor is responsible for keeping the public safe from harm and protecting private property.