The British Standard BS 5839-6: 2019 fire detection and fire alarm systems for buildings specifies that fire alarms in commercial premises should be tested on a weekly basis to ensure that they are operating effectively.
Additionally, all alarm systems should be inspected every 6 months by an independent specialist to ensure that no defects exist and to maintain the system in optimal condition, and fire drills should be performed on an ad hoc basis to ensure that building occupants know how to respond and do so effectively.