nforse wrote: I've poured through all the many-years-old threads I could find about tax calculation issues, and poked through all the various configuration screens repeatedly over the last few hours and have been unable to solve this issue.

I cannot get CBSubs 4.0.0-rc.1, under a combination of Joomla 3.3.6 and CB 2.0.4, to calculate any taxes.

Under 'Tax Rules' I have set the default to my HST rule.
Under 'Tax Rates' I have set the HST Rate at 13%, priority 1, assigned it to the HST rule, selected Buyers and Sellers everywhere for Geographic Zone, all Domestic and Export dropdowns are set to "yes" and it is published.
Under 'Geographic Zones' I've created a new zone to cover Canada, added the established country and ensured it covers all provinces and territories (Edit Entries -> New -> Canada, Canada, All, All).
In CBSubs general config I've gone to the 'Tax' tab and enabled tax computation, as well as set my System Seller Country and Province.
Then for each plan I've ensured it is using the default tax rate (HST from above) and is set to apply the taxes "valid at buying time".

When I attempt to test this all and buy a plan the total listed both in the cart and after clicking through to PayPal is the base price of the plan, no taxes whatsoever.

I'm starting to go a little loopy from confusion and frustration!

I have to imagine it will all boil down to some simple checkbox or setting I've missed but I'm out of ideas as to what that could possibly be.