This error is generated when the Invoice Register encounters an invoice and the sales tax amount in the Invoice Header record does not match the total of the sales tax amounts calculated by the system for all line items for the invoice. Two amounts are printed after this message by the report. The first number indicates the amount stored in the sales tax field of the invoice header record and the second amount is the total of the invoice line item tax amounts. The line item amounts are calculated based on the invoice line item Tax Type, Tax Code ( which stores the tax rate), and inventory taxable flag. This error can occur for several different reasons. If this error appears on the invoice register it must be corrected before sales are posted. The error indicates that sales tax information is being edited or was not correctly set up in the first place and the situation should be investigated and corrected immediately as it can cause reporting inaccuracies and possible tax liability. Some of the causes of this error and the proper way to fix them are listed below.