I only work in hotels or apartments when touring and I always let my security buddy know every detail of my location, such as room number, hotel/apart name and address, their contact number, the name I booked it in etc etc.
I then tell them when to expect me to contact them and if they don't hear within 30min/1hr to start the emergency process
I know it's maybe different to working in a flat but I would do the same as above