The consignment note, carriage order, cost statement and communications about delivery belong in one file. The acknowledgement of receipt, delivery record, payment records and, where relevant, the statement offering security should be preserved as well.
Each cost item should be linked to the specific consignment. For a collective invoice or charges added later, explain which amount is shown by the consignment note and which item was requested only later. This makes the scope of the payment duty under Article 13 paragraph 2 CMR reviewable.
For a possible loss, add the consignment data, search communications and records showing the scheduled delivery period. The file should distinguish the evidence of the carriage sequence, the loss status and the later legal assessment.