Taken from Bisac X12 v3060
| ST | Transaction Set Header | 
| BIG | Beginning Segment for Invoice | 
| REF | Reference ID | 
| N1 | Name Segment | 
| DTM | Date/Time Reference | 
| IT1 | Baseline Item Data | 
| CTP | Pricing Information | 
| TDS | Total Monetary Value Summary | 
| CTT | Transaction Total | 
| SE | Transaction Set Trailer | 
ST Transaction Set Header
| Element | Name | Value | 
| ST | Segment Identifier | ST | 
| ST01 | Transaction Set ID | 810 | 
| ST02 | Transaction Set Control Number | Assigned by Sender (unique) | 
BIG Beginning Segment for Invoice
| Element | Name | Value | 
| BIG | Segment Identifier | BIG | 
| BIG01 | Invoice Date | YYMMDD | 
| BIG02 | Invoice Number | Identifying number generated by issuer | 
| BIG04 | PO Number | Identifying number generated by the orderer | 
| BIG05 | Release/Backorder Number | 0 | 
REF Reference ID 
| Element | Name | Value | 
| REF | Segment Identifier | REF | 
| REF01 | Reference Code Identifier | BM (Bill of Lading Number) | 
| REF02 | Reference Identification | Tracking Number | 
N1 Name Segment
| Element | Name | Value | 
| N1 | Segment Identifier | N1 | 
| N101 | Name Identifier | BS = Bill and Ship To | 
| N102 | Name | Full Text Name (Optional) | 
| N103 | ID Code Qualifier | 15 = SAN | 
| N104 | SAN | SAN Number | 
DTM Date/Time Reference Segment
| Element | Name | Value | 
| DTM | Segment Identifier | DTM | 
| DTM01 | Date/Time Qualifier | 011 = Ship Date | 
| DTM02 | Date | YYMMDD | 
| DTM03 | Century Code | First two-year digits (YY, i.e. 20 for 2002) | 
IT1 Baseline Item Data
| Element | Name | Value | 
| IT1 | Segment Identifier | IT1 | 
| IT101 | Assigned Identification | Line item number | 
| IT102 | Quantity Invoiced | Number of units invoiced | 
| IT103 | Unit of Measure Code | UN = Units | 
| IT104 | Unit Price | Price per Unit | 
| IT105 | Basis of Unit Price | NT = Net | 
| IT106 | Product ID Qualifier | IB = ISBN | 
| IT107 | Product ID | ISBN# or Speedy# or EAN or UPC or Buyer# (Optional) | 
| IT108 | Product ID Qualifier |  IB =
        ISBN | 
| IT109 | Product ID | ISBN# or Speedy# or EAN or UPC or Buyer# (Optional) | 
| IT110 | Product ID Qualifier | IB = ISBN VN = Speedy # EN = EAN UP = UPC CB = Buyer�s #(contact us to use) | 
| IT111 | Product ID | ISBN# or Speedy# or EAN or UPC or Buyer# (Optional) | 
| IT112 | Product ID Qualifier | IB = ISBN VN = Speedy # EN = EAN UP = UPC CB = Buyer�s #(contact us to use) | 
| IT113 | Product ID | ISBN# or Speedy# or EAN or UPC or Buyer# (Optional) | 
| IT114 | Product ID Qualifier | IB = ISBN VN = Speedy # EN = EAN UP = UPC CB = Buyer�s #(contact us to use) | 
| IT115 | Product ID | ISBN# or Speedy# or EAN or UPC or Buyer# (Optional) | 
CTP Pricing Information
| Element | Name | Value | 
| CTP | Segment Identifier | CTP | 
| CTP02 | Price Identifier Code | SLP = Retail/List/Suggested Selling Price | 
| CTP03 | Unit Price | Retail Price | 
| CTP06 | Price Multiplier Quantifier | DIS = Discount Multiplier | 
| CTP07 | Multiplier | Discount Multiplier (discount of 20% would have .8 here) | 
TDS Total
  Monetary Value Summary
| Element | Name | Value | 
| TDS | Segment Identifier | TDS | 
| TDS01 | Total Invoice Amount | Implied decimal (39998 = 399.98) | 
CTT Transaction Totals
| Element | Name | Value | 
| CTT | Segment Identifier | CTT | 
| CTT01 | Number of line items | Number of IT1 segments | 
| CTT02 | Number of Units | Total Quantity Invoiced (sum of IT102 elements) | 
SE Transaction Set Trailer
| Element | Name | Value | 
| SE | Segment Identifier | SE | 
| SE01 | Number of Segments | Number of records in transaction | 
| SE02 | Transaction Set Control Number | Assigned by Sender (unique), (same as ST02) |