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Free tool · beta · Amazon US · runs in your browser

Amazon FBA lost & damaged inventory finder

Since November 2024 Amazon reimburses most units it loses or damages in its warehouses automatically — but not always, and you have only 60 days to claim what it misses. Open your inventory ledger and reimbursements report here and check that it paid for everything: the tool finds units marked lost or damaged, nets off units later found and units already reimbursed, and shows any left over with its own deadline. No login, and your files never leave your browser.

By Vedant Agarwal, who builds WidenMargin's toolsUpdated

1. Inventory ledger (required)
Seller Central → Reports → Fulfillment → Inventory Ledger → Detailed view → download. Pick a range covering the last 60+ days.
2. Reimbursements (optional)
Reports → Fulfillment → Reimbursements → download, same dates. Without it, nothing is subtracted as already paid.

Both files are read on this device and never uploaded.

Free for the first 50 sellers

Want this checked for you every month? Free during early access

No report to hand right now? I'm building WidenMargin to run this check on its own each month and flag lost or damaged units that look unpaid while they are still inside the claim window. Join the early-access list and we'll email you when it is ready for Amazon US sellers. Files you open on this page are never uploaded.

We only use your email to contact you about WidenMargin early access. Never sold or shared. Ask us to delete it any time. Privacy

How to download the two reports

  1. Inventory ledger: in Seller Central open Reports → Fulfillment, then Inventory Ledger. Choose the Detailed view (not Summary), all event types, and a date range covering at least the last 90 days. Generate the report, then download it as CSV.
  2. Reimbursements: Reports → Fulfillment → Reimbursements (under Payments). Pick the same date range and download it.
  3. Open both files above. If the ledger reads wrong, the "How your ledger was read" table will show which reason codes it found.

Checking once a month keeps every lost unit inside Amazon's 60-day window.

How it works

  • Lost and damaged units come from the ledger's reason codes— Amazon's own labels, not guesses from wording.
  • Found units cancel losses. A unit marked missing and later found is not claimable, so it is subtracted.
  • Only matching reimbursements are subtracted. A reimbursement for an inbound shipment or a customer return is for a different loss, so it does not cancel a warehouse one.
  • Every unit keeps its own date. Reimbursements are matched to the oldest losses first, and the 60-day window is checked per unit — so an old, expired loss never hides a recent one.

What the reason codes mean

M, 5 — missing
A unit Amazon cannot find in its bin. Counted as lost.
F, N — found
A missing unit found again, or transferred back from a wrong FNSKU. Subtracted from that SKU's lost units, oldest first.
E — warehouse damaged
Amazon damaged the unit in its fulfillment center. Counted as damaged.
6 — carrier damaged
Damaged in transit. Only sometimes Amazon's liability, so it is shown for review but not counted.
D — disposed
Amazon disposed of units. Shown for review but not counted.
H, K, U, 7 — not Amazon's fault
Customer-damaged, defective, distributor-damaged, expired. Ignored.
Q, P — disposition change
A unit moved between conditions. P re-adds what Q or E removed, so it is ignored to avoid counting twice.

Filing a claim

For a unit still inside 60 days, check first that Amazon has not reimbursed it automatically in the last few days. If not, open a case in Seller Central under Help → Get support → Fulfillment by Amazon, and give the FNSKU, the date and the reference ID from the ledger row. Keep claims factual and one issue per case.

Questions sellers ask about lost and damaged FBA inventory

Which reports do I need?

The Inventory Ledger in its Detailed view (Seller Central → Reports → Fulfillment → Inventory Ledger), and optionally the Reimbursements report for the same dates. The ledger shows every unit Amazon marked lost, found or damaged; the reimbursements report shows what it already paid for. Without the second file the tool cannot subtract what was already reimbursed, so treat its numbers as an upper bound.

Doesn't Amazon reimburse lost and damaged units automatically now?

Mostly, yes — since November 2024 Amazon reimburses most units it loses or damages in its fulfillment centers without a claim. But sellers still report units that were never paid, and anything it misses has to be claimed within 60 days. This tool is a check that the automatic payments actually happened. If it finds nothing, that is the good outcome: your reimbursements look complete for that period.

How long do I have to file a claim?

Since 23 October 2024, Amazon requires claims for units lost or damaged in a fulfillment center to be filed within 60 days of the loss being reported in its systems — down from 18 months. That is why the tool shows, for each SKU, how many units are still inside 60 days, and dates every unit on its own rather than by the oldest event.

Does this tell me how much Amazon owes me?

No. It shows units worth investigating. Amazon reimburses many warehouse losses automatically, sometimes finds units later, and decides the reimbursement value itself. If you enter an average unit cost, the tool multiplies it out as a rough guide only.

What do the reason codes like M, F and E mean?

They are Amazon's inventory-adjustment codes in the ledger's Reason column. M and 5 mean a unit is missing (lost); F and N mean a missing unit was found or transferred back; E means Amazon damaged it in the warehouse; 6 is carrier damage; D is disposal; H, K and U are customer, defective and distributor damage; Q and P are disposition changes. The tool lists every code in your file with what it did with it.

Is my data uploaded?

No. Both files are read by your own browser and cross-checked on your device. Nothing from them is sent anywhere — close the tab and it is gone.

Why is this marked beta?

It is built from Amazon's published report format and reason-code definitions and tested against realistic files, but not yet against many real sellers' ledgers. If your file does not read right, the reason breakdown will show it — and an email with just your header row (never the whole file) to hello@widenmargin.com helps fix it.

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