Merge bookings
Guests occasionally have a reservation under one booking, followed by another reservation under a different booking number (e.g if they've decided to add another night or have been staying for work and adding another day as a personal expense). Under the current system they need to check out and get their cards recut which isn't a great customer experience, we need to manually allocate the same room for both stays, inform Housekeeping not to clear the room and if they haven't paid in advance, we need to pay extra attention to their billing as it's split over multiple bookings.
In these instances it would be very useful to be able to merge or link reservations so that they're more clearly marked and are managed more intuitively in terms of cutting keys and paying bills.