Table of Contents

1. What Changed: the Amazon Reimbursement Landscape since 2023
2. How does Amazon Lost Inventory Work in 2026?
3. What Types of Lost Inventory Claims can i File?
4. How do i File a Reimbursement Claim? (Step-by-step, 2026)
5. How is my Reimbursement Value Calculated in 2026?
6. What is Amazon's AI Doing to my Lost Inventory Claims?
7. What are the most Common Mistakes Sellers Make when Filing?
8. Final Thoughts

Amazon is required to reimburse FBA sellers for inventory lost or damaged while in Amazon's possession. To file a claim in 2026, go to Seller Central → Help → FBA Issue/Reimbursement.

You must file within 60 days of the close of the relevant shipping cycle for inbound shipments, or within 18 months for warehouse loss and damage claims. As of March 2025, Amazon reimburses sellers at manufacturing cost, not market value, making proactive claim management more critical than ever.

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1. What Changed: the Amazon Reimbursement Landscape since 2023

The reimbursement system sellers used in 2023 no longer exists in the same form. Three fundamental shifts have reshaped how lost inventory claims work:

• Reimbursement value methodology (March 2025): Amazon updated its FBA inventory reimbursement policy. Compensation is now calculated at the item’s manufacturing cost, which is typically lower than the fair market value previously used. This directly compresses the dollar recovery sellers receive per lost unit.
• Shortened filing windows for inbound claims: AAmazon tightened the claim window for inbound shipment discrepancies. Sellers now have 60 days from the shipment reconciliation date to dispute inbound receiving errors, down from a more lenient multi month window. Missing this deadline forfeits your claim entirely.
• Automated reimbursements (Selective): Amazon began auto issuing reimbursements for a narrow set of loss types, particularly FBA customer return shortfalls. However, automation does not cover all claim categories. Sellers who rely solely on Amazon's self correction leave significant money unclaimed.

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2. How does Amazon Lost Inventory Work in 2026?

Amazon's fulfillment network processes millions of units daily across hundreds of fulfillment centers. Inventory loss occurs at multiple points in this system. Sellers bear the financial impact unless they actively reconcile and claim.

2.1. What are the most common causes of FBA inventory loss?

One of the most frequent causes of FBA inventory loss is inbound receiving discrepancies. This occurs when Amazon receives your shipment and scans fewer units into the system than what was originally sent. Even if your shipment left your warehouse complete and properly labeled, discrepancies can arise during the receiving and check in process at the fulfillment center.

Another common cause involves FC to FC transfer losses. Amazon frequently moves inventory between fulfillment centers to optimize distribution and delivery times. During these internal transfers, units can sometimes be lost or miscounted, resulting in discrepancies within your inventory reports.

Stranded or misplaced inventory is also a significant contributor to FBA losses. In these cases, the units may physically exist within a warehouse, but they are not properly linked to your seller account due to catalog, listing, or system issues. As a result, the inventory becomes unavailable for sale even though it has not physically disappeared.

Customer return processing failures represent another source of loss. When customers return products, those units should be processed back into either sellable or unsellable inventory. However, if the return is not properly reconciled within your account, the unit may never be reflected in your inventory records.

Finally, removal order losses can occur when you request Amazon to dispose of inventory or return it to you. During this process, units may go missing before they are successfully shipped out or properly accounted for, creating additional inventory discrepancies.

External resources: FBA inventory reimbursement policy

Related: Amazon FBA Reimbursement Policy Explained

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3. What Types of Lost Inventory Claims can i File?

Understanding claim categories is essential. Each has its own documentation requirements and filing window:

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4. How do i File a Reimbursement Claim? (Step-by-step, 2026)

Before filing any reimbursement claim, it’s essential to follow a structured process. Amazon’s system is data driven, so identifying discrepancies accurately and submitting proper documentation is key to getting claims approved:

Step 1: Run your inventory reconciliation

Pull these three reports from Seller Central before filing anything:

1. Inventory Ledger Report (Fulfillment → Inventory → Inventory Ledger)
2. Manage FBA Shipments (for inbound discrepancies)
3. Returns Report (for customer return shortfalls)

Cross reference units shipped vs. units received vs. units currently in inventory. Discrepancies are your claim basis.

Step 2: Identify eligible discrepancies

Not every discrepancy is reimbursable. Amazon auto resolves some within 30 days of the event. Check the Reimbursements report to see what Amazon has already compensated. Only claim unresolved gaps.

Step 3: Open the claim in Seller Central

1. Navigate to: Help → Get Support → FBA Issue/Reimbursement.
2. Select the correct claim type. Use the table above to match your loss event to the right category. Misclassifying a claim is the fastest way to get it denied.

Step 4: Provide supporting documentation

Amazon requires evidence that:

• The inventory existed (purchase invoices, shipping records)
• Amazon took possession (inbound tracking, receiving confirmation)
• The discrepancy has not already been resolved

Short, precise documentation wins claims faster than lengthy explanations.

Step 5: Follow up within 48 hours if denied

A denial is not always final. If your claim is rejected, respond with additional documentation referencing the specific ASIN, shipment ID, and the line items in your Inventory Ledger that evidence the loss.

External resources: Inventory Defect and Reimbursement (IDR) Portal

Related: How To Get Your Money Back From Lost and Damaged FBA Inventory

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5. How is my Reimbursement Value Calculated in 2026?

This is where the March 2025 policy change has the largest practical impact:

• Pre-March 2025 method: Amazon used the item's average sale price or fair market value to calculate reimbursement.
• Post-March 2025 method: Amazon now bases reimbursement on the item's manufacturing cost, defined as the cost you paid to acquire or produce the unit. Amazon derives this estimate from your cost of goods data or its own internal assessment if no cost data exists.

External resources:

• Calculation of reimbursement value
• FBA inventory reimbursement policy: Shipment to Amazon claims

Related: Amazon Lost Inventory: How to File a Reimbursement Claim

5.1. What this means for sellers

If Amazon calculates your manufacturing cost independently, because you have no cost data on file, it will typically estimate conservatively. Sellers with documented COGS who provide invoices on file recover meaningfully more per unit.

Operator level action: Upload your supplier invoices to Seller Central, or maintain them in a format ready to submit with every claim. This single practice is the highest leverage change you can make to your reimbursement recovery rate.

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6. What is Amazon's AI Doing to my Lost Inventory Claims?

Amazon's internal systems are increasingly AI driven. Two relevant systems affect FBA inventory management in 2026:

• Rufus (Amazon's AI Shopping Assistant): Rufus influences product discoverability based on listing quality and in stock signals. Unresolved inventory discrepancies that create phantom in stock signals can suppress your listing's Rufus driven recommendations.
• COSMO Algorithm: Amazon's COSMO system governs supply chain optimization across fulfillment centers. FC to FC transfer losses often originate from COSMO directed inventory relocations. Understanding that these moves are algorithmic, not manual, helps sellers identify the right claim category when losses occur post transfer.

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7. What are the most Common Mistakes Sellers Make when Filing?

Even experienced sellers lose valid reimbursements because the process was mishandled. Most denials trace back to a small set of recurring operational mistakes. Understanding these pitfalls is just as important as knowing how to file correctly:

• Filing after the window closes: The 60 day window for inbound claims passes faster than most sellers realize. Reconcile every inbound shipment within 45 days of the expected delivery date. Build this into your weekly operations cadence.
• Accepting Amazon's first response as final: Amazon's initial case responses are often automated. A denied claim supported by clear documentation deserves a follow up. Escalate through Seller Central's case management system with specific report data.
• Miscalculating the claim amount: With the manufacturing cost methodology, sellers who estimate their own reimbursement values without referencing actual COGS data risk either under claiming or submitting inflated amounts that trigger rejections.
• Claiming for already reimbursed units: Always pull the Reimbursements report first. Duplicate claims damage your account standing and waste the finite goodwill you have with Seller Support.

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8. Final Thoughts

Prevention is more cost effective than recovery. These practices reduce loss exposure:

• Reconcile on a fixed schedule: Weekly reconciliation of your Inventory Ledger prevents discrepancies from aging past claim windows. Monthly reconciliation is the minimum viable cadence.
• Photograph outbound shipments: Before your pallets or boxes leave your facility for Amazon, photograph the exterior, labeling, and unit counts. This documentation is your first line of defense for inbound discrepancy claims.
• Use shipment tracking obsessively: Inbound FBA shipments should be tracked end to end. If a carrier confirms delivery but Amazon's receiving system shows a unit shortfall, that tracking data is the foundation of your claim.
• Audit removal orders before closing them: When Amazon processes a removal, verify that units returned to you match the removal order quantity before marking the order complete.
• Consider third-party reconciliation tools: Platforms purpose built for FBA reimbursement auditing can identify discrepancies that manual Inventory Ledger review misses. These tools work on a contingency basis, making them accessible regardless of account size.