EDI Reference / segments / ISA
ISA
Interchange Control Header
The outermost envelope — sender, receiver, date, control number, and the delimiters for the whole interchange.
Key elements
| Element | Name | What it carries |
|---|---|---|
| ISA05/06 | Sender Qualifier & ID | Who sent it (e.g. ZZ + an agreed ID). |
| ISA07/08 | Receiver Qualifier & ID | Who it's for. |
| ISA13 | Interchange Control Number | Echoed by the IEA trailer; must match. |
| ISA15 | Usage Indicator | P = production, T = test. |
Key elements only — the ones that matter in retail trade, not the full element list.
Appears in
850 · Purchase Order
855 · Purchase Order Acknowledgment
856 · Advance Ship Notice (ASN)
810 · Invoice
997 · Functional Acknowledgment
860 · Purchase Order Change
865 · PO Change Acknowledgment
846 · Inventory Inquiry / Advice
832 · Price / Sales Catalog
816 · Organizational Relationships
824 · Application Advice
940 · Warehouse Shipping Order
943 · Warehouse Stock Transfer Shipment Advice
944 · Warehouse Stock Transfer Receipt Advice
945 · Warehouse Shipping Advice
947 · Warehouse Inventory Adjustment Advice
204 · Motor Carrier Load Tender
214 · Transportation Carrier Shipment Status
875 · Grocery Products Purchase Order
877 · Manufacturer Coupon Family Code Structure
880 · Grocery Products Invoice
See a real ISA in context — paste any X12 and the Inspector breaks out every segment.
Inspect an X12 free