Walmart EDI Integration Made Simple: A Step-by-Step Supplier Guide

Walmart’s EDI system can feel like a wall of paperwork and complicated jargon. But it’s not just filling out forms or checking boxes—it’s the backbone of getting your products into one of the world’s biggest retail networks.

At CrossBridge, we’ve helped countless suppliers make it through. It’s not easy, but it’s doable—with the proper guidance. We’ll walk you through every step, showing you what matters, what to avoid, and how to set yourself up for long-term success.

Too busy or just want it handled? Book a quick call. We’ll take the EDI load off your plate.

Let’s get into it.

1. Understanding Walmart’s EDI Requirements

Alright, before you start stressing over codes and protocols, let’s take a step back and understand what EDI with Walmart actually means. 

We’re not going to hit you with a bunch of technical jargon (well, maybe just a little), but let’s be real—Walmart’s system is a big deal for suppliers.

The good news? Once you understand the key pieces, it all starts to make sense.

EDI Format: The ANSI X12 Standard & AS2 Protocol

When you think of EDI, think of it like the language your computer uses to talk to Walmart’s system. 

The language Walmart speaks is based on ANSI X12, a specific data format that allows information like purchase orders (POs), invoices, and advance shipping notices (ASNs) to be shared between systems.

Now, to actually send this info securely and on time, Walmart uses AS2—think of it as the courier that gets your EDI messages to Walmart’s doorstep.

You’re probably wondering, “Is this really necessary?” 

Yes. Yes, it is. Without AS2, your information won’t get through the door. 

Required Documents: POs, Invoices, and ASNs

Okay, so now we know how the data gets there, but what exactly are you sending Walmart? Three key documents:

• Purchase Orders (POs): These are Walmart’s orders to you. When they need something, they send a PO, and you confirm it.
• Advance Ship Notices (ASNs): Once you ship the products, you’ll need to let Walmart know with an ASN. This is Walmart’s way of tracking exactly what’s coming in and when.
• Invoices (810): After shipping the products, you’ll send Walmart an invoice, detailing how much you’re charging.

However, there are several others that may come into play depending on your supplier type, volume, and fulfillment model.

Here’s a breakdown of the most relevant codes:

EDI Code	Document Name	Purpose	Sender
850	Purchase Order	Order from Walmart specifying SKUs, quantity, and terms	Walmart
856	Advance Ship Notice (ASN)	Shipping details: what’s been sent, how, and when it’s arriving	Supplier
810	Invoice	Billing details for the shipped goods	Supplier
997	Functional Acknowledgment	Confirms receipt of EDI documents	Supplier
855	Purchase Order Acknowledgment	Confirms acceptance or proposed changes to a PO	Supplier
820	Remittance Advice	Details of payments made by Walmart	Walmart
864	Text Message	Used to send invoice error messages or other non-structured updates	Walmart/Supplier
812	Credit/Debit Adjustment	Financial adjustments due to returns, pricing errors, etc.	Walmart
816	Organizational Relationships	Provides address and location identifiers	Walmart
990	Response to Load Tender	Used in logistics workflows (e.g., carrier responses to shipping requests)	Carrier/Supplier

Not all of these are required for every supplier, but if you’re in a high-volume or specialized category (like DSV, grocery, or international), expect several of these to come into play.

CrossBridge Tip: If you’re only seeing 3 documents today, it doesn’t mean your setup is complete. Check with your Walmart buyer or EDI provider if additional transaction codes should be supported to prevent disruption.

Global Data Synchronization (GDSN) & GS1 Standards

Now let’s talk about barcodes.

I know, I know. You’re thinking: “I just sell products, why do I need to worry about barcodes?” 

Here’s why: Walmart is a massive operation, and without a standardized way of tracking products, things would fall apart fast. That’s where GS1-128 barcodes come in. Walmart requires these codes to keep track of your products as they move through their network.

These aren’t just any barcodes. They’re GS1-128, which means they meet Walmart’s exact standards for data tracking and synchronization. Think of them as the product’s passport through the supply chain.

Who Needs to Be EDI-Ready?

If you’re selling to Walmart, you need to be EDI-ready. But here’s the kicker—Walmart’s not just for the big guys. Yes, Walmart works with large suppliers, but they also have solutions for smaller vendors, too.

If you’re a smaller supplier, don’t panic. Walmart offers a Web EDI tool for companies just getting started. It allows you to manually enter data into Walmart’s system, which is a great starting point if you don’t yet have a full EDI setup.

But—and this is important—Web EDI won’t last forever. Once you start processing more invoices, you’ll need to step up your game and switch to a more scalable EDI solution. 

At CrossBridge, we work with suppliers of all sizes. We’ve seen smaller businesses start with Web EDI, then evolve into full EDI integrations as they grow. It’s all part of the journey. And guess what? We’re right here with you every step of the way.

2. Trading Partner Setup Process

Alright, you’ve got the basics down—now let’s dive into the Trading Partner Setup Process. 

Once you understand what Walmart expects, the real work begins: setting up your systems to speak their language. This is where configuration, credentials, and testing come into play.

Step 1: Getting Into Walmart's RetailLink

The first thing you’ll need to do is get access to Walmart’s RetailLink portal. Think of RetailLink as Walmart’s central hub for all things supplier-related. It’s where you’ll manage your products, monitor orders, and—most importantly—set up your EDI connection.

New to it? Expect a learning curve. But once you’re in, it becomes your control center.

CrossBridge Tip: Ensure your RetailLink account is fully activated before doing anything else. Access issues can delay the whole setup.

Step 2: Setting Up the AS2 Connection

Now that you're in RetailLink, it’s time to set up your AS2 connection. 

This is the technical bit.

AS2 is the secure, real-time communication protocol that will allow your system to talk directly to Walmart’s system. Without this, no data will be able to transfer back and forth between you and Walmart.

You’ll need to:

1. Generate the necessary credentials for the AS2 connection.
2. Work with your IT team (or an EDI provider if you’re outsourcing this) to configure the AS2 connection.
3. Test the connection to make sure everything is secure and functional.

This part is non-negotiable. If AS2 isn’t configured properly, none of your documents will transmit.

Don’t Skip the Certificate Exchange

Setting up AS2 isn't just about enabling the protocol—it requires a formal certificate exchange and mailbox registration with Walmart’s internal systems. Miss this, and your connection will silently fail.

Here’s what’s involved:

• Generate your AS2 certificate (includes your public key, AS2 ID, and endpoint URL).
• Submit your certificate to Walmart via their onboarding team or portal instructions.
• Receive Walmart’s AS2 certificate and import it into your system.
• Register your GEM mailbox—this is Walmart’s internal routing mechanism for supplier EDI documents.

You’ll also need to provide:

• Company AS2 ID
• AS2 endpoint URL (server that receives messages)
• Contact email for EDI support issues

Once both sides have exchanged certificates, you’ll be cleared to start AS2 connectivity testing.

CrossBridge Tips: Keep a backup of your private AS2 certificate in a secure place. Expired or lost certs are a top reason suppliers go dark in production and miss PO windows.

Many suppliers hit roadblocks here. If you’re not confident, bring in an EDI provider early to avoid wasted cycles.

Step 3: Requesting EDI Transactions

Once your AS2 connection is up and running, you’ll need to request the specific EDI transactions that you’ll be using. Walmart requires you to send and receive several types of EDI documents, like the:

• 850 PO (purchase order)
• 856 ASN (advance ship notice)
• 810 Invoice.

Walmart provides implementation guides for each document. These outline the required fields, accepted formats, and data validation rules.

CrossBridge Tip: Take it slow when reading through the transaction guides. They’re dense, but you don’t want to miss a crucial detail that could delay your testing.

Step 4: The Testing Process

Testing is the critical part of this process. This is where you’ll send and receive test documents through the RetailLink portal.

Here’s how it works:

• Phase 1: Pending: You send test data to Walmart, but nothing is validated yet.
• Phase 2: Not Started: Walmart reviews the data you’ve sent and ensures it’s formatted correctly.
• Phase 3: Testing: This is the “real” testing phase, where you’ll send actual test orders, invoices, and ASNs. You’ll get feedback from Walmart on any issues, and you’ll need to fix them.
• Phase 4: Parallel: At this point, you and Walmart are fully synced. You’re exchanging documents, but nothing is “live” yet. This is a final test before you go into full production.

If you’re new to this, the testing process can feel like a never-ending cycle of sending, receiving, and tweaking. But here’s the silver lining: once you pass all tests and go live, your order fulfillment will be faster, more accurate, and much easier to manage.

CrossBridge Tip: Don’t get discouraged by failed tests. Most suppliers go through multiple rounds before approval. Fix, resubmit, repeat.

3. Navigating Walmart's EDI Network

You’re almost there! Now that your connection is set up and you’re ready to start sending live data, let’s talk about the EDI network and how to navigate it.

RetailLink Portal: Your Command Center

As a Walmart supplier, RetailLink is going to become your best friend. It’s the portal where you’ll manage your orders, monitor the status of your EDI transactions, and handle any issues that come up.

Here’s the cool part: Walmart’s EDI system is designed to be user-friendly (once you’re familiar with it). You’ll be able to see exactly where your documents are in the system, track testing progress, and receive feedback on any errors that occur. All of this is crucial to ensure everything is running smoothly.

When you log into RetailLink, you’ll see options for both item setup and EDI testing. From here, you can monitor your transactions, confirm the status of test documents, and see if anything needs attention.

CrossBridge Tip: Make RetailLink part of your daily ops routine. Delays often happen not because of broken systems, but because no one’s checking the portal.

AS2 vs VAN

Walmart’s preferred method for EDI is a direct AS2 connection. This is the most efficient way to transmit data back and forth, but what if you’re not set up for that?

Don’t worry. Walmart also works with Value-Added Networks (VANs), which are third-party services that can help route your EDI transactions. You don’t have to use a specific VAN, but you do need to make sure your VAN is compatible with Walmart’s AS2 requirements.

CrossBridge Tip: If you’re using a VAN, make sure it’s AS2-compliant and that it’s set up correctly. We’ve seen suppliers hit roadblocks when their VAN fails Walmart’s security or formatting checks.

Other EDI Connection Types: SFTP & VAN

While Walmart prefers a direct AS2 connection for most suppliers, there are a few exceptions and alternatives depending on your fulfillment model and capabilities.

1. SFTP (SSH File Transfer Protocol)

Walmart supports SFTP connections in specific cases—primarily with Drop Ship Vendors (DSVs). This allows you to transfer files over a secure channel without AS2 encryption, using account-based authentication instead.

• Used when: You’re a DSV with Walmart and cannot support AS2 due to legacy systems or internal constraints.
• Pros: Easier to set up for some IT environments.
• Cons: Not Walmart’s preferred method and may have reduced support long-term.

2. VAN (Value-Added Network)

A VAN acts as an intermediary—think of it like a post office that routes EDI documents between you and Walmart.

• Used when: You lack in-house AS2 capabilities or want a simplified, outsourced solution.
• Pros: Lower technical overhead, easier onboarding for smaller suppliers.
• Cons: Higher monthly fees, more moving parts, and sometimes slower data delivery.

CrossBridge Tip: We only recommend SFTP or VAN setups if AS2 is truly not feasible. AS2 gives you direct control and reduces latency, which is critical for high-volume or time-sensitive workflows.

Web EDI for Small Suppliers (Temporary Solution)

For low-volume suppliers, Walmart offers Web EDI—a browser-based tool where you manually enter EDI data.

It’s slow, error-prone, and unsustainable as you scale. It exists to lower the barrier of entry, not to support long-term growth.

CrossBridge Note: We set up all our clients with automated EDI immediately and don’t rely on manual day-to-day work that creates costly mistakes. We don’t think you can be too small for a fully automated system, but you can definitely be too big for a manual one.

4. Cost and Timeline Expectations for Walmart EDI Integration

How much does Walmart EDI integration cost? It depends on your setup. Smaller suppliers can get started with minimal investment, while larger operations integrating multiple systems should expect a more significant budget.

Estimated Cost Ranges

Scenario	Estimated Cost
Manual Web EDI setup	$0–$500 (Walmart-provided tool)
Basic EDI integration with a provider	$1,000–$5,000 setup + monthly fees
Mid-size supplier integrating ERP/3PL	$5,000–$25,000+ depending on complexity
Large/global suppliers with full automation	$25,000–$100,000+ (including testing, monitoring, and compliance tools)

Ongoing Costs: Expect recurring monthly fees if using a managed EDI provider or VAN (Value-Added Network). AS2 setups typically incur lower ongoing costs than VANs.

Timeline to Integrate

The Walmart EDI onboarding process takes time, especially for full automation. Here's what to expect:

Stage	Typical Duration
Internal readiness & planning	1–2 weeks
RetailLink access & AS2 setup	1–3 weeks
Document mapping & test preparation	2–4 weeks
EDI Testing with Walmart	2–6 weeks (max allowed)
Total integration time	~4–12 weeks (on average)

Important: Walmart expects suppliers to complete testing within 6 weeks. If not, they may be removed from EDI onboarding and forced to reapply.

CrossBridge Tip: Start early, plan realistically. Suppliers that underestimate setup time often lose weeks fixing issues mid-stream. Automate what you can, and avoid cutting corners in testing—it always costs more later.

5. EDI Providers and Tools

By now, you’ve got a good understanding of how to set up your EDI connection with Walmart and navigate their systems. But here's the truth: no one really does this alone. You’re going to need a little help, and that’s where EDI providers and tools come in.

Choosing the Right EDI Provider

Here’s where it gets a bit easier: Walmart doesn't require you to use a specific EDI provider, but it does require that your EDI system uses the AS2 protocol and meets Walmart’s specific document mapping standards.

When you're looking for an EDI provider, think of them as your EDI partner—they’ll provide the software and infrastructure to handle all your electronic transactions with Walmart. They’ll also ensure your system is compliant with Walmart's strict standards.

Some of the most popular EDI providers that are already pre-configured to work with Walmart’s system include:

• TrueCommerce
• SPS Commerce
• OpenText

These providers have extensive experience working with Walmart's requirements, so they can save you a lot of headaches. They handle everything from setting up the AS2 connection to ensuring that your documents are properly formatted for Walmart’s system.

CrossBridge Tip: Unless you have a strong internal tech team, go with an established provider. It saves time, avoids errors, and accelerates approval.

Web EDI vs Full Automation

For small suppliers, Walmart’s Web EDI tool can be a useful stopgap. It’s web-based and lets you manually input POs, invoices, and ASNs without needing full-fledged EDI software.

But here’s the catch: Web EDI has limitations. It’s great for getting your feet wet, but as your order volume increases, Web EDI can’t keep up. You’ll need to transition to full EDI software, and this is where tools like TrueCommerce, SPS Commerce, and OpenText really shine.

These full EDI systems allow you to automate the entire process, reducing manual data entry and the risk of human error. They integrate with your ERP and 3PL systems, meaning everything—from order entry to shipping notices—can happen automatically, saving you time and effort.

CrossBridge Tip: Don’t wait until you’re overwhelmed. Set up automation early—scaling is smoother when your foundation is already solid.

6. What EDI Doesn’t Cover

EDI is powerful—but it’s not magic. It streamlines document exchange, but it doesn’t handle everything suppliers assume it might.

Here are two key limitations to understand:

Catalog Management

EDI doesn’t let you create, edit, or upload your product catalog. All item setup must still be done manually inside RetailLink or through Walmart’s Item 360 tool. EDI only transmits transactional data—orders, invoices, shipment notices—not item creation or maintenance.

Inventory Updates

Your available stock levels are not updated in real time via EDI. Walmart systems only allow one stock status update every 24 hours, and that too typically via separate processes (e.g., API or RetailLink input). If you rely on rapid inventory updates, EDI won’t help here.

CrossBridge Tip: We see this mistake all the time—suppliers expecting EDI to manage product listings or daily stock feeds. Build separate workflows for item setup and inventory sync, especially if you're selling across Walmart’s online and in-store channels.

7. EDI Requirements by Supplier Type

Walmart doesn’t treat all suppliers the same, and your EDI setup will depend on what kind of supplier you are. The three most common categories are:

1. Warehouse Suppliers

These suppliers ship bulk inventory to Walmart’s distribution centers (DCs). This is the most common model for general merchandise and grocery.

• Required EDI Documents: 850 (PO), 856 (ASN), 810 (Invoice), 997 (Ack)
• Fulfillment Speed: Walmart expects tight delivery windows and barcode accuracy
• System Expectations: Full AS2 connection and automation recommended

2. Drop Ship Vendors (DSVs)

DSVs ship directly to Walmart customers on behalf of Walmart. You don’t handle store/DC fulfillment—you're fulfilling eCommerce orders.

• Required EDI Documents: Same core set (850, 856, 810) + possible 855 (PO Ack) and 990 (Load Tender Response)
• Connection Type: May use AS2 or SFTP, depending on technical readiness
• Additional Compliance: Packing slips and routing instructions often enforced

3. Walmart Marketplace Sellers

You sell on Walmart.com but are responsible for your own order fulfillment and customer service.

• EDI Use: Optional, and in most cases not required
• Platform: Most sellers use Walmart’s Seller Center portal or third-party tools, not EDI

CrossBridge Tip: Know your category before starting integration. We've seen Marketplace sellers waste time on a full EDI setup they didn't need, and DSVs get chargebacks for not following routing guides tied to their EDI documents.

8. Penalties for Non-Compliance

Walmart enforces EDI standards through automated chargebacks. Mistakes aren’t just annoying—they’re expensive.

Chargebacks for Missing or Incorrect Documents

Some examples of chargebacks include:

• Missing or late ASNs: If your advance ship notice (ASN) doesn’t arrive on time or contains incorrect information, Walmart can charge a fine. This can range from a flat fee of $5 to $150, depending on the nature of the error.
• Delayed PO Acknowledgments: If you don’t acknowledge a purchase order (PO) within the required time frame, you could be charged up to 1% of the invoice cost.
• Incorrect Barcodes or Labels: If the labels or barcodes on your shipments aren’t readable, or if they’re missing entirely, Walmart can slap you with additional fines. Not only that, but delayed shipments could lead to penalties, too.

These add up fast. Walmart’s systems expect clean, timely, perfectly formatted data every time.

CrossBridge Tip: Most fines are avoidable. Automate what you can, validate before sending, and double-check barcode specs.

Staying Compliant Over Time

Here’s the good news: once you’ve set up your EDI connection and automated your transactions, compliance gets much easier. Your EDI provider and Walmart’s system will send you feedback on any errors, giving you the chance to correct them before they become issues.

But Walmart updates specs—new document versions, label changes, or formatting tweaks. You’re responsible for staying updated.

CrossBridge Tip: Monitor bulletins inside RetailLink. Good EDI providers will also notify you of updates and roll out fixes, but verify they’re doing so.

Conclusion

Walmart’s EDI system is strict, but not impossible. With the right setup—AS2 connection, mapped documents, a tested provider—you’ll reduce friction, avoid chargebacks, and stay compliant at scale.

CrossBridge has helped suppliers across industries navigate this process. Whether you're starting from scratch or refining an existing setup, we can step in at any stage.

Need help implementing or managing EDI for Walmart?

Schedule a call. We’ll get it done—so you can focus on your business, not backend paperwork.