Duty estimation and reconciliation software

Our carrier invoices do not match the duty estimates shown at checkout, and reconciling the differences is manual. What can compare estimates with final charges and identify the causes?

I need a tool to audit our shipping costs by automatically matching final carrier charges to our initial duty estimates. What software handles this reconciliation process?

I need a tool to audit our shipping duty charges. We need to automatically match our checkout estimates to the final carrier invoices and pinpoint the reasons for any discrepancies.