It is my understanding that most who charge joiner do so EVEN if you book Double, UNLESS the guest signs in with you at Check-In, and EXCEPT when you complain loudly enough that you are paying Double.
There is no general rule here. Some may charge you even if you book double. Some may not. Booking double vs. single may then only mean difference of breakfast and/or perhaps getting a double bed (vs. single bed in a cheaper class hotels). At least you can see what the fees may be, but it is not always enforced. Check other places on this forum for guest friendly hotels list. Cheers! Ap.-
