Quick answer: Amazon's Inventory Ledger consolidates FBA inventory movements into summary and detailed views: starting balance, receipts, shipments, returns, removals, transfers, and adjustments by FNSKU and disposition. To investigate a missing unit or reversed reimbursement, trace the FNSKU over a date range wide enough to include the original loss, the reimbursement, the later "found" event, and any change in sellable or unsellable disposition.
A seller received reimbursement for 36 units Amazon had marked lost in the warehouse. Four months later, Amazon reversed the reimbursement because the units had allegedly been found. The inventory team checked available stock and found only six additional units. Finance saw a charge for all 36. Support replied that the units may have been recovered at a different time from the reversal. Everyone was looking at a different slice of the same event, finance at the Payments report, operations at available inventory, support at the reimbursement reason, and nobody had reconstructed the FNSKU across the full time window. That's what the Inventory Ledger is for.
What the Inventory Ledger can and cannot tell you
It's a movement record, helping answer how many units existed at the start of the period, what was received, what left through customer orders or removals, what adjustments changed inventory, and which disposition held the units. It doesn't always explain the warehouse reason in plain English, an adjustment code may require another report or Seller Support to interpret, and it doesn't replace the Reimbursements report or Payments report.
Summary view versus detailed view
The summary view verifies the inventory equation over a day, week, or month: ending inventory equals starting inventory plus receipts and positive events, minus customer shipments, removals, and negative events. If the equation doesn't balance, check filters, dispositions, and date boundaries first. The detailed view inspects individual events like adjustments, receipts, and transfers, filterable by Merchant SKU, FNSKU, event type, disposition, and fulfillment-center location.
Why a reimbursement reversal may not equal sellable inventory
Amazon states reimbursements can be reversed when inventory is later found or the original reimbursement was issued in error. "Found" doesn't necessarily mean available for sale today, the unit may be unsellable, in FC transfer, damaged, sold between the found event and the seller's check, or added as an overage connected to another shipment entirely. The audit must follow quantity and disposition together, not just the available count on the day someone looks.
Composite case study: 36 units and five event types
Downloading the detailed ledger for the FNSKU from 30 days before the original loss through 30 days after the reversal revealed the full picture: a warehouse loss adjustment of -36 sellable units (the original missing event), a warehouse found adjustment of +36 sellable units recorded three months later, then customer shipments of -22 sellable units sold before finance noticed the reversal, a damage adjustment of -8 units moved to unsellable, leaving 6 sellable units as the incremental available count operations actually observed. The reversal wasn't automatically wrong, the 36 found units had already split into 22 sales, eight damaged units, and six available units. Without the timeline, the seller saw six units and assumed Amazon had charged for 30 nonexistent units.
The unit-tracing workflow
Start with the financial event from the Reimbursements report: reimbursement ID, original type, reason, quantity, amount, date, and FNSKU. Set a wide date range, don't search only the reversal date, since recovered units may appear at a different time entirely, include the original loss and enough history to capture a related overage. Use Summary view first to confirm whether starting and ending balances reconcile. Use Detailed view for adjustments, filtering event type to Adjustments and searching for both positive and negative quantity events. Add disposition, since a positive quantity in unsellable inventory isn't equivalent to restored sellable stock. Add customer and removal events, since found inventory can leave quickly through sales, removals, or liquidation. Then reconcile the money using the Reimbursements and Payments reports.
Edge cases that create false discrepancies
The original reimbursement never appears in the searched period, expand the date range and search by reimbursement ID, FNSKU, and reason, and if there's genuinely no original credit, open a case with the exact report extracts. The unit was found under an overage in another shipment, Amazon may connect a later overage to an earlier missing quantity, search the shipment ID support references. The reimbursement and reversal use different amounts, changes in sourcing-cost estimates can create an amount mismatch, so reconcile quantity and money separately. Expiry makes the "found" unit economically different, a 2026 forum case argued inventory claimed as found couldn't be the original units because the original batch had already expired, worth maintaining lot and expiry evidence outside Amazon's aggregate ledger for expiry-dated goods.
A support case built from the ledger
State it precisely: "Reimbursement ID R123 for 12 units of FNSKU X was reversed on June 18 with the reason that the units were found. We reviewed the Inventory Ledger from January 1 through July 1. The only positive adjustment connected to the original loss is four units on May 3, all in unsellable disposition. There is no positive adjustment, receipt, overage, or transfer restoring the remaining eight units. Attached are the Reimbursements report, Inventory Ledger Summary, Detailed Adjustments export, and our unit reconciliation. Please identify the event IDs and locations for the eight units used to support the reversal." This asks Amazon to identify missing evidence rather than simply asserting the reversal is unfair.
Build a monthly reimbursement-reversal audit
Every month: download Reimbursements, filter for reversal types, group by FNSKU and original reason, pull Ledger events across the relevant history, confirm the restored quantity and disposition, confirm the financial amount, and open cases only for the unreconciled differences. This reduces the risk of discovering a six-month-old charge after the claim window has narrowed.
EcomSanity can flag unexpected inventory or profitability movement, but the Inventory Ledger is the evidence source for FBA unit events. The practical combination: EcomSanity identifies an ASIN whose stock or profit changed unexpectedly, Seller Central reports reconstruct the underlying events, and the seller records the final resolution in an audit log. For the reimbursement side of this same investigation, see Amazon FBA reimbursements in 2026.
Frequently asked questions
What can Amazon's Inventory Ledger tell me that other reports can't?
It consolidates FBA inventory movements into summary and detailed views showing starting balance, receipts, shipments, returns, removals, transfers, and adjustments by FNSKU and disposition. It's the movement record for reconstructing exactly what happened to specific units over a date range.
Why was my reimbursement reversed if I didn't see the units back in stock?
Found inventory doesn't necessarily mean available for sale today. The unit may have been found in unsellable condition, sold again before you checked, transferred, damaged, or recorded as an overage connected to a different shipment. Trace quantity and disposition together, not just today's available count.
How wide a date range should I use when tracing a reversed reimbursement?
Wide enough to include the original loss, the reimbursement, the later found event, and any change in disposition, sometimes months apart. Amazon guidance notes recovered units can appear at a different time from the reversal, so searching only the reversal date will often miss the actual event.