Hi.
Currently, you are able to remove a customers details one at a time, from their booking screen - this is encouraged, as it means their personal and credit card details are not held on your system.
We've now added a 'housekeeping' section, where you can now remove any customer information, and room booking information before a specified date. You can get to this from the menu Admin -> Housekeeping.
PLEASE NOTE
The system will ask you to confirm you want to proceed - if you do, the data held for customer bookings and room bookings for check-out dates of before the date you specified, will be removed permanently - and cannot be retrieved.