Depending on your location, when selling to customers in other states, you may need to charge sales tax.
Sales taxes have various names, in different regions of the world:
VAT (Value Added Tax)
GST (Goods and Services Tax)
HST (Harmonized Sales Tax)
PST (Provincial Sales Tax)
Sales Tax (United States)
To add tax to your bookings and invoices, use the Tax brackets on the Terms > Offer tab of the bookings:
By default, taxes will be added on top of your Guarantee, however, if needed, you can use the 'Tax is inclusive' toggle to include the tax in the amount: