Valid tracking numbers can return nothing due to carrier routing and number reuse

Order-tracking lookups often fail even when the customer's tracking number is real, leading teams to assume a parcel is lost. One cause is that TNT, now owned by FedEx, still runs a separate tracking system, so routing by company name rather than number issuer sends queries to the wrong endpoint. Similarly named carriers, such as Team Global Express, are not renamed TNT, so fuzzy brand matching can misdirect consignments. TNT also states that its eight- or nine-digit parcel numbers are reused every three or four weeks, which can cause collisions if numbers are used as primary keys. The author recommends identifying the carrier from the number and sender, keying shipments by carrier, number and ship date, and treating scans dated before the order as belonging to an earlier shipment.