Enso Connect charges only the specific upsell amount without the taxes due to the varying global policies on taxation.
Stripe, our payment processor, allows you to set up the taxes within your Stripe account, which will be accounted for by the upsells.
Here's how:
Enable Stripe Tax (More → Tax → Get Started)
Set origin address, default tax category, and behavior
Add tax registrations in relevant jurisdictions
Turn on automatic tax for invoices and products
Export tax reports and/or schedule recurring exports
Monitor threshold alerts and maintain compliance
Contact Stripe support to know more.