Please explain the 72 hours rule for transactions?

The 72 hours applies from the date of either the invoice or shipment details are available with the Economic Operator. This provides flexibility already for the economic operator that the transaction may be registered after the shipment (example invoice is generated). Once the transaction is generated, UDB will provide the PoS identifier back to the Economic Operator. The Economic Operator is able to record the emission details before the end of the 3 months balancing period or before the sale of this received consignment on UDB.