A stock discrepancy is difficult to explain when the report starts halfway through the story. For brands using Walmart Fulfillment Services on Walmart Marketplace, a recent documentation update makes the available inventory-history windows clearer.
Our recommendation is to check the coverage of your inventory records before treating an unexplained difference as an operational loss. A missing period in a report and a missing unit in fulfillment are different problems.
What Walmart clarified on October 12
In its October 12, 2026 WFS inventory logs update, Walmart clarified the US retrieval rules for its inventory activity API. When the start date is omitted, the default is the most recent 90 days. The API supports up to 365 days of US activity. For older US records, Walmart directs users to the Create report request API with WFS_INVENTORY_LOG as the report type.
These are documented retrieval rules. The announcement does not establish a new stock policy or say that older inventory activity has disappeared. The specified date behavior applies to the US market.
Start with the question and the period
Before asking your team to explain a difference, define the product, the inventory measure, and the dates under review. Are you checking a recent receipt, reconciling a quarter, or investigating activity that began much earlier?
Then confirm that the supporting extract covers that entire period. Ask your reporting owner or integration provider to show the requested dates and the dates actually returned. Do not assume that an automated report includes all history simply because it has always arrived on schedule.
Keep missing data separate from zero activity
Our recommended reporting convention is simple: make unavailable periods visible. A blank, failed retrieval, or incomplete extract should not silently become a zero in a spreadsheet or dashboard.
Keep the original file and the retrieval date alongside the working analysis. If the team reruns a report, preserve both versions until the difference is understood. That makes it easier to determine whether a changed result reflects new information, a different reporting window, or an error in the analysis.
Build a timeline before assigning a cause
Review the relevant shipment, receipt, order, return, and adjustment records available to your business. Align product identifiers and dates before comparing totals. Where records use different definitions or timing, document that difference instead of forcing them to match.
We recommend working through a small set of affected products first. For each gap, write down what is known, what is missing, and which record would resolve the uncertainty. An inventory activity log can support an investigation, but it should not be treated as proof of a cause without the surrounding evidence.
Give unresolved items an owner
Assign one person to obtain missing records and another clear owner for any resulting operational action. Keep a review date and a short explanation with each open issue. If a support case is needed, provide a focused timeline and the relevant identifiers rather than an unexplained total.
For Walmart Marketplace ecommerce operations, useful inventory reporting means more than receiving a file. It means knowing what the file covers, preserving the evidence, and turning an unexplained difference into a specific next step. Check the history first. Then decide what needs to change.