HTM 06-02/03 Permission For Disconnection of Supply
 
Whenever electrical supplies are to be made unavailable or placed at risk, including work affecting standby generators or UPS systems, the Authorised Person (LV) or Competent Person (LV) responsible must consult the person in charge of the affected area. Before any isolation occurs, a signed Permission for Disconnection of Supply form must be obtained to confirm awareness and agreement to the planned interruption