Walmart processes roughly 150,000 supplier invoices every week. Nearly all of them move through automated systems that validate, match, and pay without a human touching the document. The system does not call to clarify. It does not flag ambiguities for review. It either matches or it deducts.
An invoice that looks correct on your screen can fail at three separate checkpoints: EDI 810 validation, accounting standards, and automated three-way matching. A special character in the invoice number triggers an EDI 864 rejection. A pack size mismatch between your item file and the PO triggers a quantity claim. An invoice submitted before the freight arrives triggers a false shortage deduction. Each failure costs you money and time, and most suppliers only discover the problem when they reconcile the remittance.
This guide breaks down the exact EDI 810 requirements, the automated matching logic that determines whether you get paid in full, the timing rules that prevent false claims, and the operational habits that keep your invoices moving straight through to payment.
What Is the Walmart Invoicing Process?
Walmart processes all supplier invoices through EDI using the EDI 810 transaction set. Suppliers submit either through traditional AS2 or through WebEDI inside Retail Link. Every invoice moves through automated validation, matching, and payment systems with no manual review at the entry stage.
The process works in sequence:
- You ship product against a Walmart purchase order.
- You submit an EDI 810 invoice through AS2 or WebEDI.
- Walmart's system validates the EDI 810 against technical standards. Failures here generate an EDI 864 rejection.
- Valid invoices enter the matching system. The system compares invoice data to the PO and the receiving record.
- Invoices that match flow to payment automatically. Invoices with discrepancies generate claims or deductions.
- Payment posts to your remittance advice with any adjustments applied.
Walmart Invoice Requirements Explained
Walmart requires every EDI 810 to be a mirror image of the purchase order. The sequencing of line items should match the PO column and row for line-level matching.
Invoice number: Must contain numeric values only. No alpha characters, no special characters including hyphens, slashes, pipes, backslashes, quotes, carets, ampersands, asterisks, parentheses, dollar signs, hashes, at signs, or exclamation points. Walmart's system rejects invoices with special characters outright.
Supplier number: Must be the correct 9-digit vendor number.
Purchase order number: Must be the correct 10-digit PO number. For DSD shipments, a Walmart PO number may not exist.
Item number: Must be the Walmart item number (WIN), placed in the first column of the invoice.
UPC number: Must be the item-specific GTIN, not the case GTIN.
Quantity and cost: Must match the PO exactly. Case quantities are acceptable for DC orders only if the inner pack quantity is transmitted. Store invoice quantities must be billed in eaches.
Facility location: The ship-to GLN must be valid and must match the PO.
Payment terms: Must match the terms received on the EDI 850. Check the EDI ITD segment to ensure correct transmission.
Allowances: Must use the correct EDI allowance code that matches the PO. Using the wrong code causes the system to deduct the allowance amount again at payment.
Freight and tax: Must not be added to the invoice. Walmart's system files a claim for any overbilled freight, handling, or tax amounts.
One invoice per DC: Shipments to multiple DCs cannot be combined on a single invoice. Direct to Store shipments require a separate invoice for each individual store location.
PO type 73: For DSDC orders received at the DC and prepped for store shipment, invoice as one PO to one invoice for the initial PO. Do not invoice individual stores for a type 73 PO.
Common Reasons Walmart Invoices Fail
Invoices fail at two stages: EDI validation and automated matching. Each stage produces different outcomes.
EDI 810 validation failures
The system rejects the invoice before matching begins. You receive an EDI 864 rejection message. Common causes include:
- POC location does not match GLN
- Invalid freight indicator code
- Detail total does not match header total
- Duplicate invoice record
- Missing or invalid supplier number
- Special characters in the invoice number
Rejected invoices are not paid. You must correct the error and resubmit.
Accounting standard failures
The invoice passes EDI validation but fails Walmart's AP standards. These invoices enter manual processing, which delays payment and increases the risk of claims. Common causes include:
- Allowance amount not included
- Invalid allowance charge code
- UPC or Walmart item number missing
- Payment terms mismatch
- Quantity or cost discrepancy against the PO
Automated matching failures
The invoice passes both validation stages but does not match the PO and receiver within tolerance. The system files a claim automatically. Common causes include:
- Invoice submitted before freight arrived, triggering a shortage or POD claim
- Item file pack size mismatch causing quantity conversion errors
- Cost discrepancy between PO and invoice
- Missing or incorrect allowance codes
- Invoice lines sequenced differently from the PO
What Walmart's Automated Matching System Validates
Walmart uses two matching models depending on the shipment type.
Three-way match: Used for distribution center and Sam's Club shipments. The system compares the purchase order, the receiving record, and the invoice. All three must align within defined tolerances for automatic payment.
Two-way match: Used for direct store delivery and certain receipt-based processes. The system compares the receiving record and the invoice.
Matching occurs at the line level or summary level depending on program eligibility. The system translates all quantities to a per-each unit on both the invoice and the PO before reconciling. To eliminate conversion errors, Walmart recommends billing in eaches with an inner pack value of one.
The system also validates:
- Invoice terms against PO terms
- Item cost against PO cost
- Quantity shipped against quantity received
- Allowance codes and amounts against the PO
- Supplier number and facility GLN against the PO
If your invoice achieves a 100 percent match, Walmart calls this "The Perfect Match" and processes it automatically. If the match rate falls below 95 percent, you have a systemic problem that requires immediate correction.
Documents Required for Accurate Walmart Invoicing
Clean invoicing starts with clean upstream data. Before you submit an EDI 810, confirm these inputs are aligned:
- Purchase order (EDI 850): Verify item cost, case pack, warehouse pack, vendor stock number, UPC, payment terms, allowances, and MABD dates before shipping.
- Item file data: Confirm pack size, UPC, and cost in Walmart's system match your internal records. Item file discrepancies carry through to invoice matching.
- Advance Ship Notice (EDI 856): Must be transmitted and accepted before the trailer gates in. The ASN quantity must match what you invoice.
- EDI 997 functional acknowledgment: Confirms Walmart received your EDI 810. A rejection means the invoice was not ingested and must be resent.
- EDI 824 application advice: Identifies business rule errors in your EDI documents. Errors require correction. Warnings should be resolved proactively.
- Receiving record: Confirms what Walmart actually received. Invoice quantities must align with this record.
Suppliers who maintain alignment across these six data points achieve higher match rates and fewer claims.
How to Submit a Walmart Invoice
Log in to your EDI system or Retail Link WebEDI and follow these steps:
- Verify the PO data: Confirm item numbers, costs, quantities, terms, and allowances match your internal shipment records.
- Generate the EDI 810: Mirror the PO line sequence. Use numeric invoice numbers only. Include the 9-digit supplier number, 10-digit PO number, valid facility GLN, and correct payment terms in the ITD segment.
- Transmit via AS2 or WebEDI: Submit through your established EDI channel. Do not submit the same invoice through multiple channels.
- Check the EDI 997: Confirm acceptance within 24 hours. If rejected, correct the error and retransmit before the payment terms window closes.
For WebEDI users, generate the invoice from the PO detail view to pull data automatically. Wait one business day after PO receipt before submitting to avoid false rejections. Check the Sent Items page after 48 hours for status updates.
What to Do When Walmart Rejects Your Invoice
If your EDI 810 is rejected via EDI 864, the invoice will not enter the payment system. Correct the error and resubmit immediately.
Check the rejection reason: The EDI 864 message specifies the failure type. Common rejections include POC location mismatch, invalid freight code, detail/header total mismatch, or duplicate invoice.
Correct and resubmit: Fix the data issue in your EDI system and retransmit. Do not modify the original invoice number if the rejection was for a format issue. Use a new invoice number only if the original was a duplicate.
Monitor EDI 824 warnings: Even if the 997 shows acceptance, the 824 may flag business rule errors. Resolve warnings before they convert to errors in future system updates.
Track your match rate: Log in to Supplier One and review your payment history. If your match rate is below 95 percent, contact Walmart to identify the root cause. Common fixes include correcting item file data, aligning allowance codes, or billing in eaches instead of cases.
Why Recurring Invoice Failures Keep Happening
Patterns in consistent invoice rejections or claims point to upstream data problems, not one-off errors.
Item file mismatch: Your internal pack size, UPC, or cost does not match Walmart's item file. Every invoice inherits this error.
Allowance code errors: Using the incorrect EDI allowance code causes the system to deduct the allowance twice. Common codes include:
- C000 Defective Allowance: Code 59
- E720 New Distribution Allowance: Code 55 (Warehouse)
- E740 New Store Allowance: Code 55 (Store)
- F910 Quantity Discount: Code 57
- I570 Warehouse Allowance: Code 54
- I410 Unsaleable Merchandise Allowance
- E800 Promotional Allowance: Code 51
- I530 Volume Discount: Code 52
- D240 Freight Allowance: Code 46
Invoice timing problems: Submitting invoices on the day the PO ships often means the invoice arrives before the freight. Walmart's system files a shortage or POD claim because the receiving record does not yet exist. Submitting too late pushes payment outside the terms window.
Quantity conversion errors: Billing in cases without transmitting the inner pack quantity causes the system to miscalculate the each-level total. Walmart recommends billing in eaches with an inner pack value of one.
Recover Revenue Lost to Walmart Invoice Issues with iNymbus
A single Walmart invoice failure looks like a minor operational hiccup. An EDI 864 rejection. A quantity mismatch claim. An allowance code deduction. Across hundreds of invoices per month, those failures compound into significant revenue leakage.
Suppliers with high Walmart volume routinely write off thousands in preventable claims and deductions. They do not write them off because the claims are valid. They write them off because the manual effort to trace each failure back to its root cause exceeds the recovery value.
The break-even math flips when the per-invoice reconciliation cost drops to near zero. iNymbus monitors your EDI transmissions, payment history, and claim activity across Walmart's systems automatically. It matches each deduction to the PO, ASN, receiving record, and invoice from your systems. Then it identifies whether the claim was caused by an upstream data error, a timing mismatch, or a valid discrepancy.
The small-dollar claims that used to be uneconomical to research get resolved automatically. Item file mismatches and allowance code errors that most vendors miss because of the case-by-case labor cost become visible and fixable before the next invoice cycle.
If Walmart invoice rejections and claims are consistently hitting your remittances and you do not have the bandwidth to research them one by one, iNymbus is the direct way to flip the break-even math. The claims are already on your remittances. The EDI data is already in your systems. The only gap is the labor to connect them.
See how iNymbus automates Walmart invoice reconciliation and claim recovery to see what is recoverable in your current process.
