A Shipper's Letter of Instruction, commonly called an SLI, is the document exporters use to give their freight forwarder clear written instructions for handling an export shipment.
For US exports, the SLI can also carry much of the information a forwarder needs to prepare Electronic Export Information in AES, including product classification, export-control status, consignee details and licensing information.
The SLI itself is not the EEI filing.
It is the instruction and data document that helps the authorized agent prepare the shipment and, when properly authorized, file the EEI accurately.
That distinction matters because inaccurate information on the SLI can flow directly into the export filing.
What Is a Shipper's Letter of Instruction?
A Shipper's Letter of Instruction is a document provided by the exporter or other responsible party to the freight forwarder containing instructions and information needed to arrange an international shipment.
The document commonly serves two operational functions:
Transportation instructions
It tells the forwarder how the cargo should move.
Export documentation information
It provides information needed to prepare shipping documents and, where applicable, EEI.
BIS specifically identifies the SLI as a best-practice document for exporters using freight forwarders and states that an SLI provides clear and accurate instructions for filing and auditing EEI records.
Is an SLI Required for Every Export?
There is no universal requirement that every US export must use one standardized document called an SLI.
However, when a freight forwarder is acting as the exporter's authorized agent, written instructions and authorization become critical.
BIS' current freight-forwarder guidance recommends obtaining an SLI, POA or written authorization when filing EEI on behalf of the exporter and emphasizes that the forwarder should compare the commercial invoice, SLI and other authorization documents for discrepancies.
An SLI is therefore best understood as an operational compliance document rather than simply another shipping form.
Is an SLI the Same as a Power of Attorney?
Not automatically.
A power of attorney or written authorization establishes authority for an agent to act on behalf of another party.
An SLI supplies shipment instructions and data.
Depending on how the documentation is structured, an SLI may also contain appropriate authorization language.
But exporters should not assume that every generic SLI automatically creates every authorization required for the transaction.
The correct authorization is especially important for routed exports because Census requires the FPPI's authorized US agent to obtain a POA or written authorization from the FPPI.
Who Completes the SLI?
In a standard export transaction, the USPPI typically supplies the forwarder with the information needed to manage the shipment and file EEI when the forwarder is acting as the USPPI's authorized agent.
In practice, that often means the USPPI completes or approves the SLI.
In a routed export transaction, responsibility is more nuanced.
The FPPI appoints the US agent that files the EEI, while the USPPI remains responsible for providing specific required data elements to that agent.
The parties should therefore ensure that the instructions and authorization reflect the actual routed transaction rather than using a standard SLI without considering who has authority to file.
What Information Should an SLI Include?
SLI formats vary, but a well-structured export instruction should capture the information needed to move and document the shipment accurately.
Exporter / USPPI Information
Common information includes:
- Legal company name
- Address
- Contact information
- USPPI identification information
- Reference numbers
Consignee and Foreign Party Information
This may include:
- Ultimate consignee
- Intermediate consignee
- Foreign buyer
- Destination
- Contact information
These party fields matter for both freight execution and compliance review.
Shipment Information
Typical details include:
- Mode of transportation
- Origin
- Destination
- Requested routing
- Number and type of packages
- Gross weight
- Dimensions
- Cargo-ready date
- Special handling requirements
Commodity Information
The forwarder needs a clear description of what is being exported.
That can include:
- Product description
- Quantity
- Value
- Schedule B or applicable AES classification
- Country of origin where relevant to the transaction
- Internal product reference or SKU
Export-Control Information
Depending on the product, the SLI may also communicate:
- ECCN
- EAR99 designation
- License number
- License Exception
- No License Required determination
- Other applicable export-control information
BIS specifically expects exporters using forwarders to provide ECCN or EAR99 information and licensing authorization where applicable.
SLI vs Commercial Invoice vs EEI vs Power of Attorney
These documents are related, but they are not interchangeable.
Document | Primary Purpose |
|---|---|
SLI | Provides shipment and export instructions to the forwarder |
Commercial Invoice | Records the commercial transaction and goods being sold |
EEI / AES Filing | Electronic export information submitted to the US government |
POA / Written Authorization | Gives another party authority to act |
Bill of Lading / Air Waybill | Transportation document associated with carriage of the goods |
The information across these documents should agree.
If an SLI says the ultimate destination is Germany but the commercial invoice shows another destination, the discrepancy should be resolved rather than copied into the AES record.
BIS specifically recommends that freight forwarders question and resolve discrepancies between commercial invoices, SLIs, POAs and other written authorization documents before filing.
Why the SLI Matters for AES Filing
When a forwarder files EEI on behalf of an exporter, it depends heavily on the information supplied by the exporter.
That can include:
- Product classification
- Commodity description
- Value
- Quantity
- License information
- ECCN or EAR99
- Consignee information
- Routing and transport data
If the SLI is incomplete, the forwarder has three choices:
- Request the missing information
- Guess
- Delay the filing
Only the first is a defensible compliance process.
BIS specifically recommends that freight forwarders obtain missing information from the USPPI rather than silently filling gaps themselves.
How to Complete an SLI More Reliably
Step 1: Use the legal entity information
Do not populate the exporter field from an informal trading name if the filing requires the legal USPPI.
Step 2: Identify the transaction structure
Determine whether the transaction is standard or routed before completing authorization sections.
Step 3: Use controlled product descriptions
The description should clearly identify the merchandise.
Avoid vague descriptions that prevent the forwarder or government agency from understanding what is being exported.
Step 4: Provide the correct Schedule B or AES classification
Do not ask the forwarder to classify the product from a vague commercial description.
Step 5: Provide ECCN or EAR99 information where applicable
Export-control classification should come from the party with sufficient product and technical knowledge.
Step 6: State the license authorization accurately
Where applicable, specify the license, License Exception or other appropriate export authorization.
Step 7: Verify parties and destination
Confirm the ultimate consignee, destination and other transaction parties before submission.
Step 8: Compare the SLI with the commercial invoice
Descriptions, values, parties and destination should make sense together.
Step 9: Submit the information early enough
The SLI should reach the forwarder with enough time to review discrepancies before AES and carrier documentation deadlines.
Step 10: Retain the final version
The document may become part of the shipment's compliance record, particularly when it supports information reported in AES.
Common SLI Mistakes
Leaving classification blank
If the forwarder must repeatedly ask for Schedule B or ECCN information, the export process is already starting too late.
Using vague commodity descriptions
"Parts," "equipment" or "samples" may not provide enough information to support accurate filing.
Conflicting values
The SLI and commercial invoice should not report materially different transaction data without explanation.
Wrong consignee
The purchaser, intermediate consignee and ultimate consignee may be different parties.
Assuming NLR without a classification review
"No License Required" is a licensing conclusion, not a convenient default field.
Treating every shipment as non-routed
The authorization structure needs to reflect the actual transaction.
Signing without reviewing the data
The SLI may become the information source used to prepare government filings.
It should be reviewed accordingly.
What Should a Forwarder Do With an Incomplete SLI?
The correct response is to stop and request the missing information.
BIS guidance states that a freight forwarder filing EEI should obtain missing information from the exporter/USPPI and resolve discrepancies before submission.
That protects both parties.
The forwarder avoids inventing compliance information.
The exporter has an opportunity to correct the underlying data before the filing becomes a government record.
SLI and Routed Export Transactions
Routed transactions deserve additional care.
A standard export SLI from the USPPI should not automatically be treated as evidence that the USPPI controls the filing.
Under the Foreign Trade Regulations, the FPPI controls the routed filing relationship and authorizes the US agent.
The USPPI still supplies required data, but the parties should distinguish between:
Providing export data
and
Authorizing the EEI filing
Those are different functions.
Census' routed export guidance should therefore be reviewed whenever the foreign buyer controls the export movement.
How the SLI Fits Into the Export Workflow
A disciplined export process might look like:
- Sales order
- Party and transaction review
- Product classification
- License / compliance determination
- SLI completed
- Forwarder reviews instructions
- Discrepancies resolved
- EEI filed in AES
- ITN received
- Carrier documentation completed
- Cargo exported
The key is sequencing.
The SLI should carry decisions that have already been made.
It should not become the place where the company begins deciding what the product is, who the end user is or whether a license is required.
How WCM Worldwide Uses Export Instructions in the Freight Process
WCM Worldwide coordinates export documentation with the transportation workflow so the information required for EEI can be reviewed alongside the booking and shipping documentation.
A structured export process can connect:
- Shipper instructions
- Commercial documents
- Product classification
- ECCN / EAR99 information where applicable
- AES filing
- ITN
- Carrier documentation
- Export shipment records
That integration reduces the number of times the same information is manually re-entered across separate systems and teams.
For exporters reviewing the broader compliance process, WCM's AES Filing Explained guide covers EEI requirements, deadlines, penalties and filing responsibilities, while its USPPI vs FPPI guide explains how those responsibilities change in routed transactions.
Final Considerations
The Shipper's Letter of Instruction looks simple because it is often formatted like a standard shipping form.
Its importance comes from what happens next.
The information entered on the SLI can influence the booking, AES filing, carrier documentation and compliance record.
A reliable SLI should therefore answer four questions clearly:
Who is exporting?
What is being exported?
Who is receiving it?
Under what instructions and export authority should it move?
When those answers are complete before the forwarder begins filing, the entire export process becomes easier to control.
Frequently Asked Questions
What is a Shipper's Letter of Instruction?
A Shipper's Letter of Instruction, or SLI, is a document used to provide a freight forwarder with shipment and export-documentation instructions. BIS identifies the SLI as a useful tool for providing clear instructions for EEI filing and audit purposes.
Is an SLI the same as an AES filing?
No. The SLI provides information and instructions to the freight forwarder. EEI is the government export information submitted electronically through AES.
Who completes the SLI?
In a standard transaction, the USPPI commonly provides or approves the SLI for its freight forwarder. Routed transactions require additional attention because the FPPI controls the authorization of the US filing agent.
Does an SLI replace a power of attorney?
Not automatically. Authorization requirements depend on how the transaction and documentation are structured. A generic SLI should not simply be assumed to satisfy every POA or written-authorization requirement.
What information should an exporter give its freight forwarder?
The exporter should provide complete shipment and compliance data relevant to the transaction, including accurate commodity information, classification, value, consignee details, ECCN or EAR99 where applicable, licensing authorization and other information required to prepare the export correctly.
