You can configure your sub-blocks to be exempt from any applicable taxes or fees that have been added to your event hotels, enabling you to bill sub-blocks how you see fit, separably from the main block. 

To configure a block to be fee or tax-exempt, head to your sub-block's profile and scroll down to the "Sub-block Billing Options" section. Here, you'll find two toggles labelled under "Taxes & Fees".

Once complete, any bookings made in the front or back-ends in this sub-block will be automatically made exempt from any applicable taxes or fees.