Reference Number (Referenznummer)

A reference number — in German, Referenznummer — is an identifier that links one transaction to another: for example, your internal purchase-order number to your carrier's transport order. You will find it in the order confirmation, on the delivery note, and on the invoice. Unlike the order number, which the provider assigns, the reference number often comes from the customer or a third-party system — the PO number a company passes to its carrier so that delivery and invoice can later be matched automatically.

Where do I find the reference number?

The reference number travels on every document that belongs to a transaction. The four most common places to look:

• Order confirmation and email: Right after booking a transport, the reference appears in the confirmation email — usually next to the provider's order number, labelled "your reference" or "customer reference". Searching your inbox for exactly this number is the fastest way to retrieve the transaction.
• Delivery note and consignment note: On the delivery note, the reference sits in the header next to the delivery and order numbers. The consignment note has a dedicated field for it — on international transports, the CMR consignment note carries the sender's reference in the numbered fields at the top.
• Tracking link: Many carriers show the customer reference in their shipment tracking or even let you search by it. If you only know your own PO number, you can still locate the shipment without a tracking number.
• Invoice: The reference is stated again in the invoice header or line items — that is what allows accounting to match the invoice to the right purchase order.

If you cannot find the number anywhere: ask the sender for the reference given at booking, or ask the carrier for all numbers stored against the order.

Typical examples in logistics

• Customer reference on a transport order: The shipper provides its PO or project number; it then appears on the delivery note, invoice, and in tracking. Example: a machine builder books a direct run for a spare part and enters its maintenance order "MRO-2026-0815" as the reference — the customer's goods receipt recognises the delivery immediately.
• Payment reference: For bank transfers, the reference connects the payment to the invoice. Without it, the payment ends up in manual clearing.
• Customs and authority references: Export documents and customs declarations carry reference numbers (such as the MRN) used to match shipments during inspections.
• Returns and claims: Registering a return produces a case or RMA number — that too is a reference number, linking the return transport to the original purchase.

Why reference numbers matter

Purchasing, transport, and accounting usually run in separate systems. The reference number is the thread between them: goods receipt, invoice verification, and complaints only run smoothly when every document can be matched unambiguously. A typical example: a haulier delivers ten pallets to a central warehouse. If the recipient's PO number is on the delivery note as the reference, goods receipt books the delivery in minutes. If it is missing, the search begins — which buyer, which order, which delivery date?

So: always fill in the reference field when booking a transport — it takes seconds and saves hours later. In a transport management system, reference, order, and tracking numbers travel automatically on every document, from the order through the delivery note to the proof of delivery.

Reference vs. order vs. tracking number

Number	Assigned by	Purpose
Reference number	Customer / third-party system	Link transactions across systems
Order number	Provider	Uniquely identify the order
Tracking number	Carrier	Track the individual shipment

All three can appear on the same document — they do not conflict, they answer different questions: "Which transaction does this belong to?" (reference), "Which order is this?" (order number), "Where are the goods right now?" (tracking number).