I beg to differ.  Your solution is inadequate and simply a repeat of previous instructions.  How does it work to "delete" an invoice??? That compromises the integrity of our whole accounting records.  This is not a simple fix.  I even have entries that include "no tax" and "tax exempt" qualifiers but if AT THE TIME of original entry, the sales tax feature was automatically turned on (which was the DEFAULT setting), then no amount of fiddling with settings will fix the problem because the original invoice carries some sort of history with it.  Tell your engineers that as you all try to rectify this mistake which seems to be tied to up-selling your payroll service