Retail integration
Walmart EDI integration and automation
A practical guide for suppliers connecting to Walmart, covering the documents involved, store and drop-ship workflows, connectivity choices and how to integrate Walmart orders with your ERP.
Overview
Understanding Walmart integration
Who this is for: Suppliers and brands selling to Walmart stores, clubs or Walmart.com, including drop-ship vendors and the 3PLs and EDI teams that support them.
Walmart is one of the largest retail trading partners in the world, and it relies on electronic data interchange to manage the flow of orders, shipments and invoices with its suppliers. For most suppliers, the relationship runs on a small set of core X12 documents: purchase orders from Walmart, ship notices that describe what is on the truck before it arrives, and invoices that request payment. Functional acknowledgments confirm that each document was received.
What makes Walmart integration demanding is not the number of documents but the precision expected in each one. Ship notice contents must match the cartons, pallets and labels that physically arrive, and identifiers must line up with the original purchase order. Suppliers that sell through more than one Walmart program, such as store replenishment and drop-ship fulfillment for Walmart.com, often maintain different document flows for each program.
Walmart provides onboarding resources through its supplier platforms and developer documentation. Because requirements differ by program and change over time, suppliers should treat Walmart's current specifications as the authoritative reference and build integrations that are easy to update.
Workflows
Typical Walmart business workflows
Store replenishment order-to-cash
- 1Receive 850 purchase order
- 2Acknowledge and plan fulfillment
- 3Ship with GS1-128 labels
- 4Send 856 ship notice
- 5Send 810 invoice
Drop-ship fulfillment for Walmart.com
- 1Receive customer order
- 2Confirm and fulfill
- 3Ship to the consumer
- 4Send shipment confirmation
- 5Invoice the order
Documents and APIs
Common Walmart transactions
Documents commonly exchanged with Walmart, based on the public sources listed below. Exact requirements depend on your program, so always confirm against Walmart's current implementation guide.
| Document | Name | Direction | Purpose |
|---|---|---|---|
| 850 | Purchase Order | From Walmart | Walmart orders merchandise for stores, distribution centers or online customers. |
| 855 | Purchase Order Acknowledgment | To Walmart | The supplier confirms the order where the program requires it. |
| 856 | Advance Ship Notice | To Walmart | Describes the shipment, cartons and pallets before arrival. |
| 810 | Invoice | To Walmart | Requests payment for shipped goods. |
| 820 | Payment Order/Remittance Advice | From Walmart | Explains payments and deductions applied to invoices. |
| 852 | Product Activity Data | From Walmart | Shares sales and inventory data where provided. |
| 997 | Functional Acknowledgment | Both directions | Confirms each document was received and is syntactically valid. |
Connectivity
How companies connect
AS2
A direct, encrypted internet connection between your EDI platform and Walmart is a common choice for established suppliers.
Value-added network
Some suppliers exchange documents through a VAN or an EDI service provider that maintains the connection on their behalf.
WebEDI
Smaller suppliers can handle Walmart documents in a browser through a WebEDI service instead of running EDI software.
Challenges
Common integration challenges
Ship notice accuracy
The 856 must reflect exactly what was shipped, including carton and pallet structure, or receiving and payment can be disrupted.
Program differences
Store replenishment and drop-ship programs can use different documents and rules, so maps and processes must be kept separate.
Label and data alignment
Carton and pallet labels need to carry the same identifiers as the ship notice, which requires tight integration with warehouse data.
Keeping up with changes
Requirements evolve, so integrations need to be easy to update and re-test without disrupting production.
How ECOM helps
How ECOM can support your Walmart integration
PRISM-WebEDI
Exchange Walmart documents from a browser if you do not need full ERP integration yet.
SolutionEDI Integration
Integrate Walmart orders, ship notices and invoices directly with your ERP and warehouse systems.
ProductPRISM-SCV
Monitor acknowledgments, ship-notice timing and errors across every Walmart order.
SolutionDrop-Ship Automation
Automate drop-ship order, confirmation and invoice flows for Walmart.com.
ERP integration options
ECOM can integrate Walmart documents with your ERP through APIs, IDocs, database interfaces or flat files, so purchase orders post as sales orders and ship notices and invoices are generated from ERP and warehouse data.
Visibility and exception management
PRISM-SCV, ECOM's supply chain visibility product, is designed to follow each Walmart document from receipt to response and flag late or missing documents and mismatches, so your team can resolve exceptions before they affect the relationship.
Explore PRISM-SCVWalmart integration FAQs
Which EDI documents does Walmart typically require?
Most suppliers work with the 850 purchase order, 856 advance ship notice and 810 invoice, along with 997 functional acknowledgments. Some programs add documents such as the 855, 820 or 852. Confirm the list for your program in Walmart's current supplier documentation.
Do small suppliers need EDI software to work with Walmart?
Not necessarily. A WebEDI service lets smaller suppliers receive orders and send ship notices and invoices from a browser, with the provider handling the connection to Walmart.
Is drop-ship integration with Walmart different from store replenishment?
Yes. Drop-ship programs for Walmart.com follow their own documentation and workflows, so they are usually mapped and tested separately from store and distribution center orders.
Can ECOM integrate Walmart EDI with our ERP?
Yes. ECOM integrates Walmart documents with ERP and warehouse systems so orders, ship notices and invoices flow without re-keying, and monitors the flow in PRISM-SCV.
Is ECOM a Walmart-certified provider?
This page is an integration guide. It does not indicate a certification or partnership with Walmart. ECOM builds Walmart integrations to Walmart's published requirements.
Sources and accuracy
This guide summarizes publicly available information as of October 2026. Walmart sets its own requirements and can change them at any time; your Walmart implementation guide, supplier portal or account contact is the authoritative source for your program.
- Walmart Developer Portal, supplier documentation Official Walmart source
- SPS Commerce, How suppliers can connect with Walmart Third-party source
Walmart is a trademark of its owner. Its mention does not imply endorsement of, or a partnership with, ECOM Specialist.
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Request Walmart integration assistance
Tell us about your Walmart program, documents and ERP. We will outline the connection, mapping and testing plan.