A parcel goes missing, a stranger tries the gate, or a smoke alarm chirps at 3am. Any of these pushes a homeowner to start shopping for a new system. Then the choices pile up. Wired or wireless, camera or no camera, monitored or not. This guide sorts those choices into a clear order, so the decision feels smaller. It suits anyone weighing doorbell and alarm fitting services for a house, flat, shop or office in London.