Walmart EDI Requirements: The Complete 2026 Guide

Introduction: Why Walmart EDI Matters

Landing Walmart as a retail partner is a defining moment for any consumer brand. With over 4,700 U.S. stores and $611 billion in annual revenue, Walmart represents the single largest sales opportunity in American retail.

But here’s what most brands discover after the celebration: becoming a Walmart supplier and staying a profitable Walmart supplier are two very different challenges.

The difference? EDI compliance.

Walmart pioneered electronic data interchange in retail. They mandated EDI for suppliers in 1988 - decades before most retailers required it. Today, their requirements are among the most rigorous in the industry. Every purchase order, advance ship notice, and invoice must flow through EDI in precise formats. Deviations trigger chargebacks that can erode margins by 2-5% or more.

This guide covers everything you need to know about Walmart EDI requirements in 2026:

• The complete list of required EDI documents
• Step-by-step setup process from onboarding to go-live
• Retail Link integration requirements
• GS1 and GTIN compliance standards
• ASN specifications that prevent chargebacks
• Common errors and how to avoid them

Whether you’re preparing for your first Walmart purchase order or optimizing an existing supplier relationship, this guide will help you achieve and maintain full EDI compliance.

Walmart EDI Requirements Overview

What is Walmart EDI?

Walmart EDI (Electronic Data Interchange) is the standardized system Walmart uses to exchange business documents with suppliers electronically. Instead of paper purchase orders, emails, and manual invoices, all transactions flow through structured data formats that integrate directly with Walmart’s systems.

Key Point: Walmart requires ALL suppliers to be EDI-capable. There is no manual alternative for ongoing business. If you want to sell to Walmart, you must implement EDI.

Walmart EDI Standards

Walmart uses the ANSI X12 EDI standard, the dominant format in North American retail. Specifically, Walmart requires:

• Version: ANSI X12 4010 or 5010 (depending on document type)
• Communication Protocol: AS2 (Applicability Statement 2) - the secure internet-based protocol
• Testing Environment: Walmart requires successful testing in their certification environment before go-live

Supplier Types and Requirements

Walmart categorizes suppliers into different programs, each with specific EDI requirements:

Direct Import Suppliers

• Ship products directly from overseas manufacturing
• Additional customs and logistics documentation
• Extended lead times accommodated in EDI timelines

Domestic Suppliers

• Ship from U.S.-based warehouses or distribution centers
• Standard EDI document set
• Strict ASN timing requirements

DSD (Direct Store Delivery) Suppliers

• Deliver directly to individual Walmart stores
• Modified EDI requirements for store-level transactions
• Route accounting integration

Marketplace Sellers

• Walmart.com third-party sellers
• Different EDI requirements than retail suppliers
• Integration through Walmart Marketplace APIs

Required EDI Documents for Walmart Suppliers

Walmart requires suppliers to support a core set of EDI transaction sets. Here’s the complete breakdown:

Core Required Documents

EDI 850 - Purchase Order The foundation of every Walmart transaction. When Walmart wants to buy products, they send an 850.

• Contains: Item numbers, quantities, prices, ship-to locations, requested delivery dates
• Frequency: Varies by product velocity (daily to weekly)
• Response required: EDI 855 acknowledgment within 24 hours

EDI 855 - Purchase Order Acknowledgment Your confirmation that you received and can fulfill the purchase order.

• Purpose: Confirms receipt, flags any issues with quantities or items
• Timing: Must be sent within 24 hours of receiving the 850
• Critical: Failure to send triggers compliance flags

EDI 856 - Advance Ship Notice (ASN) The most chargeback-prone document. Tells Walmart exactly what’s coming, when, and how it’s packaged.

• Contains: Shipment details, carton contents, tracking numbers, SSCC labels
• Timing: Must be sent BEFORE shipment arrives (typically within 30 minutes of ship)
• Accuracy: Must match physical shipment exactly or chargebacks apply

EDI 810 - Invoice Your bill to Walmart for goods shipped.

• Contains: Line items, quantities, prices, payment terms
• Timing: Sent after shipment, typically within 24 hours
• Matching: Must reconcile with 850 and 856 or payment delays occur

Additional Document Types

EDI 846 - Inventory Inquiry/Advice

• Reports your current inventory levels
• Enables Walmart to optimize ordering patterns
• Required for some supplier programs

EDI 860 - Purchase Order Change Request

• Walmart’s modifications to original orders
• May adjust quantities, dates, or ship-to locations
• Requires acknowledgment via 865

EDI 865 - Purchase Order Change Acknowledgment

• Your response to Walmart’s change requests
• Confirms acceptance or flags issues

EDI 820 - Payment Order/Remittance Advice

• Walmart’s notification of payment
• Details deductions, chargebacks, and net payment

Document Requirements Summary Table

Walmart EDI Setup Process: Step-by-Step

Setting up EDI with Walmart involves multiple phases. Here’s what to expect:

Phase 1: Supplier Agreement and Onboarding

Step 1: Accept Supplier Agreement After Walmart’s merchandising team approves your products, you’ll receive a Supplier Agreement through Retail Link. This documents:

• Product assortment and pricing
• Payment terms
• Compliance requirements
• EDI mandate

Step 2: Complete Supplier Information Register your company details in Walmart’s systems:

• Legal entity information
• Tax identification (W-9)
• Banking details for ACH payments
• Primary and backup contacts

Step 3: Obtain Walmart Supplier Number Walmart assigns a unique supplier number that identifies you across all their systems. This number appears on every EDI transaction.

Phase 2: EDI Provider Selection and Configuration

Step 4: Choose an EDI Provider You have three options for Walmart EDI connectivity:

1. Full-Service EDI Provider (Recommended for most brands)
   • Provider handles all technical setup
   • Managed mapping and compliance
   • Faster time to go-live
2. Self-Managed EDI Software
   • You configure and maintain EDI
   • Requires technical expertise
   • Lower ongoing costs, higher complexity
3. Web EDI through Retail Link
   • Manual entry through Walmart’s portal
   • Only viable for very low volume suppliers
   • Not scalable for growth

Russ Wallace, CEO & Co-founder of Freestyle, emphasizes speed in provider selection:

“As a startup, our biggest advantage is speed of execution. Having a partner, like Crstl, who shares that same advantage and acts quickly was incredibly valuable, especially when it allowed us to get EDI set up with UNFI sooner, which in turn allowed us to secure better payment terms.”

Step 5: Configure AS2 Connection AS2 is Walmart’s required communication protocol. Configuration involves:

• Generating security certificates
• Exchanging certificates with Walmart
• Configuring encryption settings
• Testing connectivity

Step 6: Build Document Mappings Your EDI system must translate Walmart’s specific formats to your internal systems:

• Map Walmart fields to your ERP/WMS
• Configure item number cross-references
• Set up location code translations
• Define exception handling rules

Phase 3: Testing and Certification

Step 7: Complete Certification Testing Walmart requires testing before you can transact live. The certification process includes:

Document Testing

• Send test 855, 856, and 810 documents
• Walmart validates format compliance
• Correct any errors identified

Scenario Testing

• Full order-to-invoice cycle
• Partial shipment scenarios
• Cancellation handling

Step 8: Receive Production Approval

‍Once testing passes:

• Walmart enables your production connection
• You receive notification to begin live transactions
• Initial orders are monitored closely

Phase 4: Go-Live and Optimization

Step 9: Process First Live Orders

• Monitor initial transactions carefully
• Verify ASN timing and accuracy
• Confirm invoice matching
• Address any exceptions immediately

Step 10: Ongoing Compliance Management

‍EDI is not “set and forget”:

• Monitor compliance scorecards in Retail Link
• Address issues before they become patterns
• Update mappings when Walmart changes requirements
• Scale operations as volume grows

Timeline Expectations

Walmart Retail Link and EDI Integration

What is Retail Link?

Retail Link is Walmart’s supplier portal - the command center for your Walmart business. While EDI handles automated document exchange, Retail Link provides:

• Sales Data: Item-level sales, inventory, and forecasting
• Compliance Scorecards: OTIF, ASN accuracy, and other metrics
• Item Management: Product setup, images, and content
• Financial Data: Invoices, payments, and deductions
• Communication: Alerts, announcements, and buyer messaging

How EDI and Retail Link Work Together

EDI and Retail Link are complementary systems:

OTIF (On-Time In-Full) and EDI

Walmart’s OTIF program measures supplier performance on two dimensions:

On-Time: Did the shipment arrive within the delivery window?
‍In-Full: Did the shipment contain the correct quantities?

EDI directly impacts OTIF:

• ASN Timing: Late ASNs cause “not on-time” failures
• ASN Accuracy: Mismatched ASNs cause “not in-full” failures
• 855 Timing: Late acknowledgments flag potential delivery issues

OTIF failures trigger chargebacks - typically 3% of the affected order value.

GS1 and GTIN Requirements for Walmart

GS1 Company Prefix

Before selling to Walmart, you need a GS1 Company Prefix - the foundation of all your product identification.

What it is: A unique identifier assigned to your company by GS1 (the global standards organization)

What you get:

• Ability to create GTINs (UPCs) for your products
• Ability to create SSCC codes for shipping containers
• Access to GS1 US Data Hub

Cost: $250 initial fee + $50/year (for up to 10 products) to $10,500 initial + $2,100/year (for up to 100,000 products)

GTIN Requirements

GTIN (Global Trade Item Number) is what most people call a “UPC.” Walmart requires GTINs on:

Every Sellable Unit

• Consumer-facing products must have unique GTINs
• Each size, flavor, or variety needs its own GTIN
• Inner packs and cases need separate GTINs

GTIN-12 Format

• Walmart uses GTIN-12 (12-digit UPC-A format)
• Must be registered in GS1 US Data Hub
• Must match product content and images

SSCC Requirements for ASN

SSCC (Serial Shipping Container Code) identifies every carton you ship to Walmart.

Structure: 18-digit code following GS1 standards

• Extension digit (1 digit)
• GS1 Company Prefix (variable)
• Serial reference (variable)
• Check digit (1 digit)

Requirements:

• Every carton must have a unique SSCC
• SSCC must be encoded in GS1-128 barcode on shipping label
• SSCC must match ASN (856) data exactly
• Carton contents must match ASN detail

GS1-128 Label Requirements

Walmart requires GS1-128 compliant shipping labels on every carton:

Required Elements:

• SSCC barcode (Application Identifier 00)
• Ship-to postal code
• Ship-from information
• PO number
• Item description
• Quantity

Format Specifications:

• 4” x 6” label size
• Specific barcode quiet zones
• Human-readable text below barcodes
• Walmart-specified label placement on cartons

Josh Lazenby, Senior Operations Manager at KitchenSupply, highlights support importance:

“The ability and willingness of Crstl to help is night and day compared to other providers. They’re not just a vendor; they’re genuinely invested in our success.”

Walmart ASN Requirements (EDI 856)

The ASN is the most critical - and most error-prone - EDI document for Walmart suppliers. Getting it right prevents chargebacks and maintains your compliance scores.

ASN Timing Requirements

When to Send:

• ASN must be transmitted BEFORE shipment arrives at Walmart DC
• Best practice: Send within 30 minutes of carrier pickup
• Maximum: Send before carrier’s last scan en route

Why Timing Matters:

• Walmart uses ASN data to plan receiving operations
• Late ASNs cause receiving delays
• Delays impact OTIF scores and trigger chargebacks

ASN Content Requirements

Every Walmart ASN must include:

Header Level (Shipment)

• Shipment ID
• Ship date and time
• Carrier information (SCAC code)
• Bill of lading number
• Ship-from and ship-to locations

Order Level

• Purchase order number
• PO date

Pack Level (Tare)

• SSCC for each carton
• Carton weight and dimensions

Item Level

• GTIN/UPC for each item
• Quantity per carton
• Lot numbers (if applicable)
• Expiration dates (for perishables)

Hierarchical Structure

Walmart ASNs follow a specific hierarchical structure:

Shipment (HL Level 1)
└── Order (HL Level 2)
   └── Tare/Pack (HL Level 3)
       └── Item (HL Level 4)


This hierarchy must be maintained exactly. Incorrect nesting causes rejections.

Common ASN Errors

SSCC Mismatches

• ASN SSCC doesn’t match physical label
• Carton scanned at DC returns error
• Result: Chargeback + receiving delay

Quantity Discrepancies

• ASN says 24 units, carton contains 23
• Receiving count doesn’t match
• Result: Chargeback + inventory discrepancy

Missing Cartons

• Physical shipment has carton not in ASN
• Can’t be received without ASN data
• Result: Chargeback + potential return

Timing Violations

• ASN arrives after shipment
• Walmart can’t plan receiving
• Result: OTIF failure + chargeback

Common Walmart EDI Errors and Chargebacks

Understanding Walmart Chargebacks

Walmart deducts chargeback fees directly from your payments. Common categories include:

Must Arrive By Date (MABD) Violations

• Shipment arrives outside delivery window
• Typically 3% of affected PO value
• Tracked in OTIF scorecard

ASN Errors

• Late ASN transmission
• ASN content doesn’t match physical shipment
• Missing or incorrect SSCC data

Labeling Violations

• GS1-128 labels not compliant
• Labels not placed correctly
• Barcode not scannable

Packaging Violations

• Incorrect case pack quantities
• Ti-Hi (pallet configuration) doesn’t match spec
• Damaged or non-compliant packaging

Chargeback Costs

Preventing Chargebacks with AI-Powered EDI

Modern AI-powered EDI platforms prevent chargebacks through:

Pre-Transmission Validation

• Validate ASN against Walmart specifications before sending
• Flag quantity mismatches against PO
• Verify SSCC uniqueness and format

Predictive Compliance

• ML models identify patterns that historically triggered chargebacks
• Proactive alerts before issues occur
• Continuous learning from your transaction history

Real-Time Monitoring

• Track ASN transmission timing
• Alert when approaching deadlines
• Automated escalation for at-risk shipments

Ryan Chen, CFO & Co-founder of Neuro, experienced this difference:

“Crstl delivers a product that makes traditional platforms look like a protection racket. As a fast-emerging brand, Crstl enables us to adapt and scale without viewing us as another pocket to pick.”

Walmart EDI Compliance Checklist

Use this checklist to verify your Walmart EDI readiness:

Before Onboarding

• [ ]  GS1 Company Prefix obtained
• [ ]  GTINs created for all products
• [ ]  Products registered in GS1 US Data Hub
• [ ]  EDI provider selected and contracted
• [ ]  Internal team identified (operations, finance, IT contacts)

During Setup

• [ ]  Walmart Supplier Number received
• [ ]  Retail Link access configured
• [ ]  AS2 certificates exchanged with Walmart
• [ ]  AS2 connectivity tested and confirmed
• [ ]  Document mappings built (850, 855, 856, 810)
• [ ]  ERP/WMS integration configured
• [ ]  GS1-128 label templates created
• [ ]  SSCC generation process established

Certification Testing

• [ ]  Test 855 accepted by Walmart
• [ ]  Test 856 accepted by Walmart
• [ ]  Test 810 accepted by Walmart
• [ ]  Full order cycle tested (850 → 855 → 856 → 810)
• [ ]  Partial shipment scenario tested
• [ ]  Certification approval received

Go-Live Readiness

• [ ]  Operations team trained on EDI workflows
• [ ]  Exception handling procedures documented
• [ ]  Chargeback monitoring process established
• [ ]  Escalation contacts identified at EDI provider
• [ ]  Retail Link compliance dashboards bookmarked

Ongoing Compliance

• [ ]  Weekly OTIF scorecard review
• [ ]  Monthly chargeback analysis
• [ ]  Quarterly EDI mapping review
• [ ]  Annual GS1 data verification

Frequently Asked Questions

What are the basic Walmart EDI requirements?

Walmart requires all suppliers to exchange documents electronically using ANSI X12 EDI standards over AS2 protocol. The core required documents are: EDI 850 (Purchase Order), EDI 855 (PO Acknowledgment), EDI 856 (Advance Ship Notice), and EDI 810 (Invoice). Suppliers must also comply with GS1 standards for product identification (GTIN/UPC) and shipping labels (GS1-128 with SSCC).

How long does it take to set up Walmart EDI?

With legacy EDI providers, Walmart EDI setup typically takes 8-14 weeks from contract to go-live. This includes provider onboarding (2-4 weeks), AS2 configuration (1-2 weeks), document mapping (2-4 weeks), and certification testing (2-4 weeks). Modern AI-powered EDI platforms can compress this timeline to 1-3 weeks total.

What is the cost of Walmart EDI?

Walmart EDI costs vary based on your provider and transaction volume. Legacy providers typically charge setup fees ($1,000-5,000), monthly minimums ($300-1,000), and per-document fees ($0.10-0.50 per transaction). AI-powered EDI platforms often use flat subscription pricing ($500-2,000/month) without per-document fees. Additional costs include GS1 membership ($250-10,500/year) and potential integration development.

What happens if I don’t comply with Walmart EDI requirements?

Non-compliance results in chargebacks deducted directly from your payments. Common penalties include 3% of PO value for OTIF failures, $50-500 per ASN error incident, and $25-200 per labeling violation. Persistent non-compliance can result in reduced orders, removal from supplier programs, or termination of the supplier relationship.

Can I use web EDI instead of full EDI for Walmart?

Walmart offers Retail Link web EDI for very low-volume suppliers, allowing manual document entry through their portal. However, this is not practical for suppliers with more than a few orders per week. Manual entry is error-prone, time-consuming, and doesn’t scale. Most suppliers need automated EDI integration.

What is OTIF and why does it matter for EDI?

OTIF (On-Time In-Full) is Walmart’s supplier performance metric. “On-Time” measures whether shipments arrive within the delivery window. “In-Full” measures whether shipments contain correct quantities. EDI directly impacts OTIF because ASN timing and accuracy determine how Walmart measures your performance. OTIF failures below threshold (typically 98%) trigger automatic chargebacks.

How do I handle Walmart EDI chargebacks?

When you receive a chargeback, first identify the root cause using Retail Link data. Common causes include late ASNs, quantity mismatches, and labeling errors. Dispute invalid chargebacks through Retail Link’s dispute process within the allowed window (typically 30 days). For valid chargebacks, fix the underlying process issue to prevent recurrence. Track chargeback trends monthly to identify patterns.

Do I need different EDI for Walmart.com vs Walmart stores?

Walmart retail (stores) and Walmart Marketplace (walmart.com third-party sellers) have different requirements. Retail suppliers use traditional EDI as described in this guide. Marketplace sellers use Walmart’s API-based integration platform instead of EDI. If you sell through both channels, you may need both integration types.

Conclusion

Walmart EDI compliance isn’t optional - it’s the foundation of a profitable supplier relationship. The retailers who thrive with Walmart treat EDI not as a technical burden but as an operational capability that enables growth.

The key takeaways from this guide:

1. Understand the RequirementsWalmart expects EDI 850, 855, 856, and 810 documents transmitted via AS2 protocol, with strict timing and accuracy requirements. Non-compliance triggers automatic chargebacks.

2. Invest in the Right InfrastructureYour EDI provider choice determines your speed to market and ongoing compliance burden. AI-powered platforms offer dramatically faster onboarding and built-in compliance safeguards.

3. Focus on ASN AccuracyThe EDI 856 (ASN) is where most chargebacks originate. Timing, SSCC accuracy, and quantity matching must be perfect. Predictive validation catches errors before they cost you money.

4. Monitor ContinuouslyWalmart EDI is not “set and forget.” OTIF scorecards, chargeback trends, and compliance metrics need regular attention. Address issues before they become patterns.

5. Scale with ConfidenceWhen your EDI foundation is solid, Walmart growth becomes an opportunity rather than an operational nightmare. The right infrastructure lets you focus on selling more product, not managing more complexity.

The brands winning with Walmart are those who view EDI compliance as a competitive advantage - not a necessary evil. Modern, AI-powered EDI makes that advantage accessible to emerging brands, not just enterprise suppliers with dedicated EDI teams.

Ready to Simplify Walmart EDI?

Get compliant with Walmart in days, not months. See how AI-powered EDI prevents chargebacks and accelerates your retail growth.

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This guide is maintained by Crstl, the modern B2B commerce network. Crstl helps brands like KitchenSupply, Elavi, Freestyle, Neuro, and Immi achieve EDI compliance with major retailers including Walmart, Target, UNFI, and Whole Foods.