In the UK, you are generally allowed to have visitors in your hotel room during the day, but there are strict legal and safety limitations regarding overnight stays. Most hotels follow a policy where guests are welcome in common areas like the lobby or bar, and can visit your room until a certain "cutoff" time (usually 10:00 PM or 11:00 PM). If a guest stays past this time, they are often considered an "unregistered occupant." This is primarily a fire safety and insurance issue; the hotel is legally required to have an accurate manifest of every person sleeping in the building in case of an evacuation. If you have a room booked for one person and a second person stays overnight, the hotel may charge you an "extra person" fee or require the guest to provide identification at the front desk. Budget chains like Travelodge or Premier Inn are often quite strict about this, while luxury hotels may be more discreet but still bound by the same safety laws. If you plan on having someone stay over, it is always best to book for two people from the start, as the price difference is often negligible, but the legal peace of mind for the hotel is significant.