What is the difference between the Viettel Post bill-of-lading code and the order ID?

The bill-of-lading code (Ma phieu gui) is the tracking number Viettel Post assigns to the physical shipment, while the order ID is the reference the shopping website uses for your purchase. They are often different. Always track with the bill-of-lading code; the order ID will usually return no result unless the store states the two are identical.