This incorporates overcharges and undercharges, as well as incorrect region or commitment pricing levels applied to a line item.
Download your pricing extract and make sure your customers are being invoiced correctly.
The Applied Contract Price in your report should equal the Total Amount (excl GST) divided by the Quantity Invoiced. If when looking at your sales report, there is a discrepancy in values of Total Amount divided by Quantity Invoiced to what you have entered as the Applied Contract Price, there will surely be an error. Checking this consistency in your report and then investigating such discrepancies prior to submission will greatly reduce Price Charged and Quantity Invoiced errors.