Where the EPOS / PMS interface supports an account limit, Caterbook can make this available to the POS.
From Settings / Property / Property list click to edit the Property.
From the Other tab, set your Default EPOS room account limit.
This can then be over ridden at Room level within the booking before the guest is checked in.
(It is possible to change the room level limit after a guest is checked in, but you would need to Refresh rooms from the Cloudhook menu link for it to be sent to the POS.)
We would strongly recommend that you test this feature before relying on it, as different POS vendors may not support this or implement this in different ways.