Form Options Costs | How to add tax fee for the bookings ?

Such configuration possible in the Booking Calendar Business Medium or higher versions.

1) You need to add the "hidden" checkbox option, which checked by default to the booking form at WP Booking Calendar > Settings > Booking Form page. Please note, you need to edit the booking form in Advanced mode (not simple mode for the booking form configuration).

Example of the checkbox shortcode and HTML code to hide this checkbox:

<div style="display:none;">[checkbox my_tax default:on ""]</div>

2) Now you can open the WP Booking Calendar > Prices > Form Options Costs page and configure additional cost for our option. If we need to set tax as 6%, then we need to set value as 106 and selection option "% of total cost" in the selectbox.