UCR vs MRN: Understanding Trade Identification Numbers in International Trade

In international trade, customs authorities rely on reference numbers to identify and track shipments moving across borders. Two of the most important identifiers used in global trade are the Unique Consignment Reference (UCR) and the Movement Reference Number (MRN).

Although both numbers are used to monitor shipments and facilitate customs procedures, they serve different purposes within the international trade system. Understanding the difference between a UCR and an MRN is essential for exporters, importers, and customs brokers who need to ensure accurate documentation and smooth border clearance.

This guide explains what UCR and MRN numbers are, how they are used in customs declarations, and the key differences between them in international trade.

Table of Contents

1. What Is a Unique Consignment Reference (UCR)?
2. What Is a Movement Reference Number (MRN)?
3. Key Differences Between UCR and MRN
4. Why Trade Identification Numbers Are Important
5. Consequences of Incorrect or Missing Reference Numbers
6. Frequently Asked Questions About UCR and MRN

What is a Unique Consignment Reference (UCR)?

A Unique Consignment Reference (UCR) is a globally recognised shipment identifier used to track an international consignment from its origin to its final destination.

The UCR is typically generated by the exporter and remains associated with the shipment throughout its journey, even if the goods cross multiple borders or pass through several customs jurisdictions. The purpose of the UCR is to create a single reference that links all documentation, data, and activities associated with a specific shipment.

Customs authorities and trade participants use the UCR to:

• Track shipments across international borders
• Link export declarations with import declarations
• Facilitate customs audits and compliance checks
• Consolidate shipment data across different systems
• Reconcile customs payments and documentation

Because international trade involves multiple customs authorities, the UCR allows data relating to a shipment to be connected between different countries and systems. This makes it easier for authorities processing customs declarations to connect export data with import data.

UCR Number Structure

Each country determines its own structure for a UCR number. However, most UCR formats contain the following elements:

• the year of export
• the country where the goods were exported
• the exporter’s registration or export code
• a unique company-generated reference number (such as an invoice or purchase order number)

In South Africa, the UCR number typically follows a structured format defined by local customs regulations.

What is a Movement Reference Number (MRN)?

A Movement Reference Number (MRN) is a unique identification number issued by customs authorities when an electronic declaration is submitted for importing, exporting, or transiting goods.

Unlike the UCR, which is generated by the exporter, the MRN is automatically generated by the customs authority once a declaration is successfully lodged within the customs system.

Every time a shipment is declared at a border, the customs authority responsible for that declaration generates an MRN. This reference number allows authorities to monitor the progress and status of the customs declaration.

The MRN is commonly used to:

• track customs declarations
• monitor shipment clearance status
• manage import, export, and transit procedures
• identify the declaration within customs systems

If a shipment passes through multiple countries, each customs declaration submitted in those countries may generate its own MRN. These identifiers help authorities manage import documentation and maintain accurate records of goods moving across borders.

MRN Number Structure

The structure of an MRN varies between customs authorities. In South Africa, an MRN generated by SARS follows a specific format determined by the customs declaration system.

Key Differences Between UCR and MRN

Although the UCR and MRN are both used to identify shipments within international trade systems, they serve distinct functions within the customs process.

In simple terms, the UCR identifies the shipment itself, while the MRN identifies a specific customs declaration related to that shipment.

Why Trade Identification Numbers Are Important

Trade identification numbers such as UCR and MRN play an important role in maintaining efficient international trade operations.

These identifiers allow customs authorities to:

• improve border security
• verify shipment documentation
• track goods moving across borders
• ensure compliance with trade regulations
• facilitate the exchange of information between customs authorities

Accurate reference numbers help ensure that shipments can move efficiently through customs processes while maintaining regulatory oversight. Proper identification numbers are also important when working with tariff codes and other regulatory requirements associated with cross-border trade.

Consequences of Incorrect or Missing Reference Numbers

Providing incorrect customs reference numbers can lead to significant complications during the import or export process.

Potential consequences include:

• shipment delays at customs
• rejected customs declarations
• increased inspection or compliance checks
• financial penalties or administrative sanctions
• suspension or cancellation of trade privileges

Ensuring that the correct UCR and MRN numbers are recorded on shipment documentation helps prevent these issues and contributes to a smoother customs clearance process. Businesses that frequently trade internationally often rely on customs compliance services to reduce these risks.

Conclusion

In conclusion, Unique Consignment Reference (UCR) numbers are a mandatory number that is generated by the exporter and is used in tracking and tracing a shipment and its data from end-to-end. The number follows a particular format that is often according to individual country regulations, but generally contains information relating to the year and country from which a consignment is coming, as well as a number connecting to the exporter. A Movement Reference Number (MRN) is a customs-generated number after a shipment has been declared at a border, and is also used for the purpose of tracing and tracking a shipment and its information. Both of these figures are necessary to have on all documentation relating to a shipment, and must be correctly shown in order to prevent any negative implications on the exporter.

References: 

South African Reserve Bank.  Manual Section B.5 – Import Verification System.

SARS. 2024. SC-CF-55-A01 – Completion of Goods Declarations – External Annexure. 

WCO. Unique Consignment Reference (UCR).

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