Different Qualifiers in Reference Identification (REF) Segment

In EDI X12, the REF segment (Reference Identification) is used to convey identifying information like account numbers, invoice numbers, customer codes, and other references that relate to the transaction set.

Each REF segment uses a qualifier to indicate what kind of reference is being provided.

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Common REF Qualifiers and Their Meanings

Qualifier	Meaning
IA	Internal Vendor Number
BT	Batch Number
CO	Customer Order Number
DP	Department Number
DO	Delivery Order Number
IV	Seller’s Invoice Number
PO	Purchase Order Number
RE	Release Number
SI	Shipper’s Identifying Number for Shipment
TN	Transaction Reference Number
MR	Master Reference (Bill of Lading, etc.)
PK	Packing List Number
ZZ	Mutually Defined
CN	Carrier’s Reference Number
VR	Vendor ID Number
SY	Social Security Number
L1	Letters or Notes Number
2U	Coupon Redemption Number
A8	Secondary Vendor Number
RZ	Returned Goods Authorization Number
AN	Associated Purchase Orders
ST	Store Number
VN	Vendor Order Number
CR	Customer Reference Number
C4	Change Number
UC	U.P.C. Case Code

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Example of a REF Segment

REF*PO*123456~

• PO = Purchase Order Number
• 123456 = The actual PO number

REF*IA*SUPP001~

• IA = Internal Vendor Number
• SUPP001 = The supplier's internal ID