Customs Declaration: The Guide to Securing Your Import-Export Operations

In 2024, French customs processed more than 218 million declarations. Every item of goods entering or leaving the customs territory of the European Union must be the subject of a customs declaration. This formality determines the fluidity of your logistics flows, the amount of duties and taxes you pay, and your regulatory compliance. Poorly managed, it leads to border hold-ups, unexpected extra costs, or reassessments. Well managed, it becomes a competitiveness lever.

What Is a Customs Declaration?

A customs declaration is the legal act by which an economic operator assigns a customs regime to its goods. It is defined by the Union Customs Code (UCC), the regulatory framework that harmonizes customs procedures across the 27 member states.

This declaration fulfills three functions. It serves to identify goods: their nature, origin, provenance, and destination. It is then used to calculate the applicable customs duties and taxes, based on the tariff classification and the declared value. Finally, it feeds into external trade statistics.

Whether you are importing electronic components from China, exporting food products to the United Kingdom, or transiting goods through France to another member state, the customs declaration is a mandatory step. It comes in several types depending on the operation: import declaration (IM), export declaration (EX), transit declaration (T1/T2), or release for free circulation.

Who Is Required to File a Customs Declaration?

Operators Required to Declare

Every company that imports or exports goods outside the European Union is required to file a declaration. Industrialists who import raw materials, distributors who ship finished products, freight forwarders who organize transport on behalf of their clients: all are concerned.

To operate at customs, a prerequisite is essential: having an EORI number (Economic Operators Registration and Identification). This unique number, issued by the customs administration, identifies each operator within the European Union. Without it, no declaration can be filed.

Direct and Indirect Representation

You are not required to file your declarations yourself. Two modes of representation allow this task to be entrusted to a professional.

In direct representation, the registered customs representative (RDE) acts in your name and on your behalf. You remain the declarant in the legal sense, and you bear the responsibility for the accuracy of the information declared.

In indirect representation, the RDE acts in their own name but on your behalf. They then share the customs debt liability with you. This mode is common when the importer is not established in the European Union.

For many SMEs, outsourcing customs clearance to a customs agent remains the safest solution, especially when operations are complex or infrequent.

What Information Appears in a Customs Declaration?

The declaration brings together data that allows the administration to control the goods and calculate applicable duties:

• The identification of the parties involved in the operation (importer, exporter, declarant, representative)
• The description of the goods, based on the tariff species (10-digit TARIC code) which determines the applicable customs duty rate
• The customs value, calculated according to UCC rules, incorporating the price of the goods, transport costs, insurance, and any royalties, in connection with the Incoterms in the commercial contract
• The customs regime requested (release for free circulation, customs warehouse, inward processing, transit...)
• The transport information (mode, means, route)

A major change is underway. The old Single Administrative Document (SAD), with its 56 boxes, is gradually giving way to the new customs declaration provided for by the UCC. This consists of approximately 120 data elements, organized in three segments (D for declaration data, GS for goods groups, SI for items). The transition from the paper SAD to the electronic message is now confirmed.

Documents Required to Clear Your Goods

At the time of filing the declaration, several supporting documents must be available. Their nature varies depending on the type of operation and the goods, but certain ones are systematically required:

• The commercial invoice, which establishes the value of the transaction
• The transport document (maritime bill of lading, air waybill or AWB, CMR road consignment note)
• The certificate of origin, essential for benefiting from a preferential duty rate under a trade agreement
• The packing list, which details the physical content of the shipment

Depending on the nature of the products, additional documents may be required: health or phytosanitary certificates for food products, import licenses for goods subject to quotas, specific authorizations for dual-use goods. Checking the required document list in advance avoids hold-ups at the customs checkpoint.

How to File a Customs Declaration in France?

The DELTA Systems

In France, declarations are filed electronically via the systems of the General Directorate of Customs and Indirect Taxes (DGDDI). Historically, two platforms coexisted: DELTA-G for traditional freight and DELTA-X for express freight and postal parcels.

Since 2025, the new system DELTA I/E (Import/Export) is progressively replacing these tools. It incorporates the structure of the new customs declaration and enables digitalized filing compliant with the UCC. Access is via the "Mon compte" section of the douane.gouv.fr portal. For small shipments under 150 euros in value, the DELTA-H7 system offers a simplified procedure.

Through national centralized clearance (DCN), it is possible to file a declaration with one customs office while having the goods presented at another location in the territory. Your goods can arrive at Le Havre and your declaration be processed from another point in France.

Simplified Declaration and Global Supplementary Declaration

For high-volume operators, the simplified procedure allows goods to be cleared with a reduced set of information, on condition that the declaration is completed at a later stage via a global supplementary declaration (GSD).

This procedure requires prior authorization from the customs administration. Operators holding Authorized Economic Operator (AEO) status access it more easily, as this status attests to their reliability and mastery of procedures. AEO audits, conducted every three years, verify the traceability and archiving of all operations.

The Mistakes That Cost You (and How to Avoid Them)

An incorrect tariff classification is the most common error. Assigning the wrong TARIC code to goods falsifies the customs duty calculation and exposes the operator to a reassessment during a post-clearance inspection. Using a code provided by a supplier without verifying it is a frequent risk.

An incomplete customs value is another pitfall. Declaring only the invoice amount without incorporating transport costs, insurance, or royalties amounts to understating the taxable base. The administration then performs a recalculation, with penalties.

Poorly documented origin is particularly costly. Claiming a preferential rate without having the appropriate supporting documents (supplier declaration, EUR.1 certificate, statement on origin) exposes the importer to a duty recovery, sometimes over several years of operations.

Incoterms inconsistent with the commercial contract or the declaration, or insufficient documentation at the time of filing, complete the picture of recurring errors.

French customs recognizes the "right to make mistakes" for good-faith operators. But this arrangement does not exempt from payment of any duties and taxes owed. The DGDDI has published a guide to the most frequent errors in this context.

The best prevention comes from systematically verifying tariff codes, cross-checking documents before filing, and using tools that structure data entry and reduce the risk of omission.

Simplifying Your Declarations with Digital Tools

Customeo, the platform developed by Derudder, allows customs operations (import, export, transit, T2L) to be submitted and tracked from a single interface. Each file has a tracking timeline with real-time statuses: to be prepared, taken in charge by the declarant, declaration prepared, goods cleared. Commercial documents are uploaded by the client, customs documents returned by the declarant, all centralized and accessible by simple reference search.

For exports, the exported clearance status — which constitutes the tax clearance justifying the tax-free sale — is collected automatically by Customeo. In the event of a tax inspection, the operator accesses all their declarations in a few clicks, without resorting to physical archives. During the last AEO audit conducted by customs at Derudder, this ability to instantly retrieve any file was particularly appreciated by the agents.

Reusable declaration templates, structured fields with only 4 mandatory fields to create a request, automatic alerts in the event of a hold-up, integrated messaging with the declarant: these features reduce data entry errors and save significant time for teams processing several dozen operations per month.

Conclusion

The customs declaration determines the speed of your flows, the amount of your duties and taxes, and your customs compliance. Correctly identifying the appropriate customs regime, gathering the right documents in advance, ensuring the accuracy of the tariff classification and customs value, and relying on tools that structure the process: these are the fundamentals of mastered customs clearance.