New: Multi-Line Multi-Quantity (MLMQ) Migration Guide

Date: April 8, 2026

We have published a new Multi-Line Multi-Quantity (MLMQ) Migration Guide for Walmart Marketplace APIs. The guide provides instructions for updating your integration from the legacy Multi-Line Single Quantity (MLSQ) model to MLMQ and outlines required changes across Orders, Returns, and Refunds APIs.

What changed

Added: MLMQ Migration Guide for Walmart Marketplace APIs
Documented: Required API updates across Orders, Returns, and Refunds
Clarified: Differences between MLSQ (legacy) and MLMQ (required) models

Why it matters

Provides guidance for migrating existing integrations to MLMQ
Helps prevent errors in order processing, especially for partial operations
Required for bundle and pack-based fulfillment capabilities

Next steps

Review the MLMQ Migration Guide
Update your integration to support MLMQ
Test changes in a sandbox environment
Request MLMQ enablement after updates are complete

Refer to the MLMQ Migration Guide for full implementation details.