To avoid double bookings it is advisable to enter the bookings you already have. You have different options:
*In CALENDAR you will find a row INVENTORY. The number shows rooms remaining to sell. They can be edited to quickly change your availability. Doubleclick to open a popup and save the changes.(it is only possible to lower the number based on the value in Settings > Properties > Rooms > Setup > Quantity of this type and any existing bookings)
*To ''Add Bookings'' manually click on the suitcase icon in the CALENDAR or on the "Add Booking" link in the BOOKINGS menu.
*If you are comfortable working with .csv you can upload bookings into Beds24 using our API (https://www.beds24.com/api/). You will see the instructions when you click on putBookingCSV (https://www.beds24.com/api/putbookingscsv.php)