Use compulsory extras for cleaning fees, security deposits, etc.

You can now make extras compulsory for guests booking online. So you can automatically apply things like one-time cleaning fees, security deposits and any other charge which isn't part of the room charge but you still want to make compulsory.

Under Accommodation > Extras, create an extra for the charge you wish to make, check "Bookable Online", then check "Make compulsory":

Guest booking online will now always have that extra added to their booking, and they'll see it listed on the extras page of the booking widget, along with any other optional extras you might have, like this: