Who’s in Charge? Using the SLI to Define Liability Between Shipper and Forwarder

A Shipper's Letter of Instruction (SLI) is a document that tells a freight forwarder exactly how to handle an export shipment; it clarifies responsibilities, routing, customs instructions, and liability allocation between the shipper and the forwarder.

A Shipper's Letter of Instruction (SLI) is a written set of directions that a shipper gives to a freight forwarder or logistics provider describing how a particular export or import shipment should be handled. The SLI acts as the operational bridge between the shipper's intentions and the forwarder's actions: it sets routing, documents required, customs information, packaging or marking requirements, special handling needs, and critical clauses about responsibility and liability. For newcomers, think of the SLI as a formal checklist plus a short contract that ensures everyone understands who does what and who is accountable if something goes wrong.

Why the SLI matters for liability

Freight forwarders typically operate under their own terms and conditions and are intermediaries that arrange transport, customs clearance, and related services. The SLI documents the shipper's instructions and often contains specific language allocating risks, requiring insurance, or imposing limits on the forwarder's responsibility. Properly drafted, an SLI reduces ambiguity, helping prevent disputes over loss, damage, delays, or customs penalties by making the parties' expectations explicit.

Core contents of a practical SLI

• Shipper and consignee details: legal names, addresses, contact persons, and tax/ID numbers where required for customs.
• Shipment description: commodity details, weight, dimensions, number of packages, HS codes, and value for customs and insurance.
• Routing and mode: preferred carrier, port/airport of loading and discharge, routing instructions, and any transshipment limits.
• Documentation instructions: which documents to prepare (commercial invoice, export declaration, packing list, certificate of origin), and how many originals/copies of the bill of lading or AWB are needed.
• Customs and compliance instructions: export license details, sanctions checks, and any special regulatory declarations.
• Insurance and liability preferences: whether the shipper asks the forwarder to arrange cargo insurance and the desired coverage level; who bears the cost; and specific clauses on liability limits.
• Special handling: temperature control, hazardous materials instructions, palletization, or SKUs requiring special care.
• Payment and charges: who is responsible for freight, duties, taxes, and any third-party charges.
• Signatures and authority: an authorized shipper signature or electronic approval and a clear statement that the forwarder is authorized to act on the shipper's behalf for specified tasks.

How the SLI defines liability between shipper and forwarder

The SLI can affect liability in several practical ways:

• Instruction versus responsibility: The SLI establishes the shipper's instructions. If the forwarder follows those instructions and loss occurs due to the instruction itself (for example, improper packing requested by the shipper), liability may remain with the shipper.
• Forwarder duties: If the forwarder negligently fails to follow the SLI or performs services incompetently (misdeclares goods, fails to obtain necessary permits), the forwarder can be held liable within the limits set by its own terms and applicable law.
• Limitation of liability clauses: Forwarders commonly operate under standard terms that limit their liability per package, per kilogram, or by international rules (e.g., Warsaw/MC rules for air, CMR for road). The SLI can reference or attach those terms and should highlight any deviations requested by the shipper.
• Insurance allocation: The SLI clarifies who is responsible for arranging and paying for cargo insurance. If the shipper requires the forwarder to procure insurance, the SLI should specify coverage level, insuring clauses, deductibles, and beneficiary details.

Practical examples

Example 1: Shipper provides inadequate packing instructions. The SLI notes 'pack as per supplier instructions' and the shipper signs off. If damage occurs due to poor packing, the forwarder may be able to show it merely followed the shipper's instruction, shifting liability to the shipper unless the forwarder failed to advise or refused the unsafe instruction.

Example 2: Forwarder misdeclares HS code on customs documents. Even if the SLI listed the correct code, if the forwarder altered it or entered it incorrectly without shipper approval and customs penalties follow, liability will likely rest with the forwarder for negligence.

Best practices when preparing or receiving an SLI (beginner-friendly)

1. Be specific: Avoid vague wording. Exact addresses, commodity descriptions, and numeric values reduce misunderstanding.
2. Reference terms: Attach or reference the forwarder's standard terms and conditions and note any exceptions you require.
3. Clarify insurance: State who will arrange insurance and the coverage amount or insuring clause.
4. Document authority: Only have authorized personnel sign or submit SLIs and keep records of approvals.
5. Confirm verbal instructions: If you make a phone change, follow up with an updated SLI or written confirmation.
6. Review liability limits: If the forwarder limits liability and you need greater protection, specify commercial value and arrange additional insurance or negotiate terms.

Common mistakes to avoid

• Relying on oral instructions alone — they are hard to prove in disputes.
• Failing to provide accurate commodity descriptions, values, or HS codes — leads to customs problems, fines, and denied claims.
• Assuming the forwarder is automatically insured to full value — confirm and document insurance arrangements.
• Not checking the forwarder’s standard terms — these often contain important liability caps and time limits for claims.

Legal and practical considerations

SLIs are not a substitute for formal contracts, but they are strong evidence of intention and instruction. Different jurisdictions and transport modes impose varying limits on carrier and forwarder liability; the SLI should therefore be aligned with the chosen route and service. Also, using clear Incoterms references in the SLI helps clarify who bears risk at each point in the supply chain.

Final tip

Treat the SLI as more than paperwork. It is a communication and risk-management tool. A well-drafted SLI prevents surprise costs, speeds customs clearance, and reduces disputes by making the division of responsibility between shipper and forwarder explicit. For shippers new to international logistics, a friendly, clear SLI aligned with carrier terms and insurance cover will save time and money when something inevitably goes wrong.