EDI 810: The Invoice, Explained in Depth

The EDI 810 is the Invoice - the supplier's electronic bill for goods or services delivered. It is the EDI counterpart of a paper invoice, and it normally arrives after the goods have shipped, referencing the original purchase order. For accounts-payable teams, the 810 is the document that triggers payment.

How the 810 fits the order cycle

An 810 almost always references an earlier 850 purchase order and frequently follows an 856 advance ship notice. The buyer's accounts-payable system performs what is called a three-way match:

1. The purchase order (850) - what was ordered.
2. The goods receipt - what actually arrived, often derived from the 856 ASN.
3. The invoice (810) - what is being billed.

If all three agree on quantities and prices, the invoice can be approved and paid automatically, with no human intervention. If they disagree - a price mismatch, a short shipment, an extra charge - the invoice is flagged for review. This automation is a major reason EDI invoicing exists: it turns a manual matching chore into an exception-only process.

The key segments of an 810

BIG - Beginning Segment for Invoice

Carries the invoice date and number, and references the original PO. BIG*20240225*INV-3391*20240115*PO-99831 means invoice INV-3391 dated 2024-02-25, against purchase order PO-99831 dated 2024-01-15. The invoice number and the referenced PO number are the two anchors that tie this document to the rest of the cycle.

N1 loop - Parties

Identifies the parties, such as remit-to (RI), bill-to (BT), and vendor. The remit-to tells the buyer where to send payment.

IT1 - Baseline Item Data (Invoice Line)

One per billed line, mirroring the PO1 from the order. IT1*1*100*EA*12.50**UP*012345678905 reads: line 1, quantity invoiced 100, unit of measure EA, unit price 12.50, identified by UPC. AP systems compare these lines against the original PO1 lines.

TDS - Total Monetary Summary

The invoice total, usually expressed in cents with an implied decimal. TDS*168750 means $1,687.50. This is the figure the buyer is expected to pay.

SAC - Service, Promotion, Allowance, or Charge

Optional segments for discounts, freight, handling, or other charges and allowances that adjust the total. A freight charge or an early-payment allowance appears here.

ITD - Terms of Sale

Payment terms, such as net 30 or 2% discount if paid within 10 days. These terms drive when and how much the buyer pays.

A complete worked example

ST*810*0001~
BIG*20240225*INV-3391*20240115*PO-99831~
N1*RI*ACME SUPPLY CO~
IT1*1*100*EA*12.50**UP*012345678905~
IT1*2*50*EA*8.75**UP*012345678912~
TDS*168750~
ITD*01*3*2**10**30~
SE*8*0001~

In plain English: Acme Supply Co is billing the buyer on invoice INV-3391, referencing purchase order PO-99831. There are two lines: 100 units at $12.50 and 50 units at $8.75. The invoice total is $1,687.50, with terms of 2% discount if paid within 10 days, otherwise net 30.

Why amounts look strange

New readers are often puzzled that the total appears as 168750 rather than 1687.50. Many monetary and quantity fields in X12 are transmitted without an explicit decimal point; the implied decimal position is defined in the trading-partner's implementation guide. So 168750 with two implied decimals is read as 1,687.50. Always confirm the decimal convention in the spec rather than guessing.

Common pitfalls when reading an 810

• Mismatched PO reference. If the BIG references the wrong PO number, the three-way match fails and the invoice will be rejected. This is one of the most common EDI invoice errors.
• Charges not reflected in the total. SAC charges must be consistent with the TDS total, or the invoice will not reconcile.
• Unit-of-measure differences. If the invoice bills in cases but the order was in eaches, quantities will appear to disagree even when they are correct.

Frequently asked questions