A Shipper's Letter of Instruction (SLI) is a document the U.S. Principal Party in Interest (USPPI, typically the exporter) provides to a freight forwarder, authorizing the forwarder to prepare export documentation and file the Electronic Export Information (EEI) in the Automated Export System on the exporter's behalf.
A complete SLI typically includes:
- USPPI name, address, and EIN
- Ultimate consignee and intermediate consignee, if any
- Forwarding agent designation and Power of Attorney reference
- Country of ultimate destination
- Commodity description with Schedule B or HTSUS number
- Quantity, weight, and value of the goods
- License authority (e.g., NLR, license number, license exception)
- Method of transportation and carrier identification
- Routed transaction indicator — whether the foreign buyer is selecting the carrier and is responsible for export
The SLI doubles as a written Power of Attorney authorizing the forwarder to file the EEI. Without an SLI on file, the forwarder cannot legally transmit AES data on the USPPI's behalf.
In a routed export transaction, the foreign buyer (or its U.S. agent) controls the movement of the goods and is responsible for filing the EEI. The USPPI still has to provide commodity and value data to the filer — and the SLI is how that handoff is documented.
The SLI is not filed with the U.S. government — it stays in the exporter's records and supports the filings made in AES. Errors in EEI data trace back to the SLI, so accuracy and recordkeeping matter.