That's right - you are responsible for tax in most states as soon as the sale is executed, regardless whether the customer pays at that time.
However, there is differing opinions about what happens if the customer does not pay. From what I understand, in some states (and countries for that matter) you can recoupe the sales tax if the customer never pays. Essentially, instead of simply writing off the bad account, you can "return" the sale on account which would give you negative tax, then adjust you inventory for the item the customer "stole" which writes off the value of the lost inventory. The net effect is that you do not pay for tax that you never collected.
BeanSmart website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.