Matching of e commerce supply data triggers discrepancy notices and addition to output tax liability if unrectified. Reconciliation requires matching the e commerce operator's reported state of place of supply and net taxable value with the supplier's outward supplies; matching dates follow any extension of the supplier's return deadline and may be further extended by the Commissioner. Prescribed communications must notify both parties of discrepancies, and amounts not rectified in the supplier's return or the operator's monthly statement are added to the supplier's output tax liability.