QBO does NOT calculate sales tax correctly...even if the invoice is created in QBO (vs a 3rd party system) and the "Ship To' address is entered correctly.

This causes MAJOR issues for YOUR customers because QBO calculates and reports the sales tax incorrectly, thereby resulting in YOUR customers reporting and paying sales tax inaccurately...which could then lead to audits and penalties with the State taxing agencies.

This is definitely a huge problem for YOUR customers and therefore should be a huge problem for QBO as well.