# Shipper's Letter of Instruction (SLI)

*Last updated: 2026-06-26*

> Shippers and exporters use the Shipper's Letter of Instruction (SLI) to provide their freight forwarder or airline with all the information needed to process an air cargo shipment.

Shippers and exporters use the Shipper's Letter of Instruction (SLI) to provide their freight forwarder or airline with all the information needed to process an air cargo shipment. It is the primary source document for preparing the Air Waybill (AWB), covering consignee details, commodity description, weight, declared value, and charge responsibility (prepaid or collect). Special handling requirements, insurance instructions, and hazardous goods declarations in line with IATA regulations are recorded here as well. The SLI is not a contract of carriage but an authorisation: it empowers the forwarder to act on the shipper's behalf and issue the relevant transport documents. A fully completed SLI cuts down on queries and speeds documentation turnaround considerably.

**Source:** [https://www.iata.org](https://www.iata.org)

## Quick Facts

| Property | Value |
|---|---|
| Term | Shipper's Letter of Instruction (SLI) |
| Language | EN |
| Word count | 113 |
| Last updated | 2026-06-26 |
| Source | https://www.iata.org |

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