What do order numbers look like?

Order numbers are numeric or alphanumeric references assigned by the buyer's or seller's order management system. A common B2B format combines a prefix, a date code, and a sequential count — for example, PO-20240315-0042. The format varies entirely by the issuing organisation. No standardised format exists in EU freight regulation or CMR documentation requirements. The only requirement is that the number is unique within the issuing party's system and consistent across every document in the same transaction.