Within preferential trade frameworks, proof of origin is a critical compliance requirement that underpins tariff relief, audit defensibility, and the integrity of origin claims across supply chains.

Obtaining proof of origin is one of the key requirements under any FTA / origin rules, alongside conducting origin calculations by the suppliers. There are various legal and practical methods/forms of proof of origin known, some of which are the following:

• Certificate of origin
• Government-issued certificate (e.g. in APAC or Latin America)
• Self-issued / movement certificate EUR-MED / EUR1 / ATR / UK EUR1 / Pan-Euro-Mediterranean (PEM)
• Invoice declaration / statement on origin (usually stated on commercial invoices)
• Supplier declarations (such as LTSDs, often used for the origin calculations)
• Developing countries trading scheme / generalised system of preference / form A

Some proofs of origin serve different purposes, and it is the responsibility of traders to ensure the correct form is used when proving origin to the authorities.

One of the most commonly used forms of proof of origin among traders is the invoice declaration, which is made out on a commercial document, such as a commercial invoice.

The majority of FTAs (e.g. US-Australia, Korea-EFTA, Japan-Mexico, EU or UK FTAs) provide specific wording for the invoice declaration or statement, which must be clearly displayed, and often there are additional rulings or considerations associated. For example, in the majority of EU FTAs, the use of invoice declarations is linked to authorised exporter status under the REX system.

Once the REX number is included in the statement on origin in the commercial invoice, the value of the goods can exceed €6,000, enabling the importer to claim preferential treatment, that is paying nil duties. Without a REX registration, the exporter may still issue a statement on origin for consignments valued at €6,000 or below.

However, each FTA includes different provisions to facilitate trade, and some provide the possibility of claiming preference based on the knowledge that imported goods qualify for preferential treatment. One example is the US-Singapore FTA, the US-Morocco FTA, and the EU-UK FTA.

Looking closer at the UK and EU Trade Cooperation Agreement, this FTA includes an importer’s knowledge clause, which allows the importer to claim preference without a statement on origin on the invoice at the time of import, provided that imported goods are still eligible.

However, businesses should be very cautious when using the importer’s knowledge option, as customs authorities have the right to request full origin documentation and calculations from the supplier to verify the claim, and apply penalties for any non-compliance.

There are additional complexities associated with the misuse of importer’s knowledge. For example, origin calculations may involve highly confidential data, such as the exporter’s own suppliers’ product prices, that the exporter may be unwilling to disclose. In certain cases, administrative complications can arise, potentially leading to cooperation between the customs authorities of the exporter’s and importer’s countries, which is a lengthy and burdensome process.

As a best practice, importers should ensure that the supplier has carried out preferential origin calculations in advance and is able to provide supporting evidence promptly upon request.

Common mistakes and best practices

The process of obtaining proof of origin can be complex, depending on the supply chain and supplier relations. It also requires specialist knowledge to ensure full compliance with the regulations set out in FTAs, and compliance should be present throughout the supply chain.

When dealing with supplier declarations, common errors include text inconsistencies, expired validity periods, and incorrect origin or product information due to a lack of supplier updates. These errors may cause compliance issues upon customs audit and have knock-on effects on other actors within the supply chain.

Best practice includes verifying that LTSD wording aligns with the legal text of the relevant FTA annex upon receipt, maintaining records of document validity periods, and maintaining consistent communication with suppliers to capture sourcing changes.

Another consideration is compliance with electronic supplier declaration provisions. For example, EU supplier declaration guidance refers to LTSD signature authentication requirements, whereas in the UK, as long as the supplier’s responsible official is recognised, an electronic LTSD does not require a signature.

In certain industry cases, some EU customs authorities still request original versions of documents, making it important to consult national-level provisions governing electronic documentation.

While frameworks such as the UK’s Electronic Trade Documents Act, the UNCITRAL Model Law on Electronic Transferable Records, and the ICC Digital Standards Initiative significantly promote trade digitisation and common standards, traders must remain informed of evolving requirements. This ensures readiness to transition from paper-based to electronic documents, such as electronic bills of lading or electronic certificates of origin, and to capitalise on these developments.

For deeper insight into proof of origin requirements, preferential trade compliance, and practical implementation across jurisdictions, explore the full Exporters Guide here