Amazon FBA businesses look simple from the outside: products ship, Amazon handles fulfilment, and revenue appears in a dashboard. Underneath, the value depends on account health, supplier relationships, product rankings, and inventory that may be worth far less than its cost. Due diligence has to cover all of them.

Start with sales and margin verification. Ask for Amazon Seller Central reports and reconcile them with bank deposits and supplier invoices. Calculate true margin after Amazon fees, fulfilment costs, advertising, refunds, and storage fees — many sellers quote margins before advertising, which can be the largest single cost. Look at the trend over 12 to 24 months, not just the last quarter.

Next, check account health. Review performance notifications, policy warnings, intellectual property complaints, and review manipulation risks. A single unresolved complaint can threaten the account, and Amazon can suspend a seller with little warning. Ask whether the brand is registered, whether listings have ever been suppressed, and whether any products face regulatory or safety restrictions.

Then examine the supply chain. Confirm supplier identities, pricing, lead times, and minimum order quantities, and check whether supplier relationships and pricing will transfer to you. Ask about product quality issues, returns, and whether the seller owns any moulds, packaging designs, or trademarks. A business whose supplier will not work with a new owner is a much weaker asset.

Finally, value the inventory honestly. Inventory is often included in the sale price, but slow-moving or seasonal stock may take months to sell, and Amazon charges storage fees all the while. Count units, check sell-through rates, and exclude damaged or stranded inventory from your valuation. An FBA deal is only as good as its inventory, its account standing, and its supplier terms — verify all three before closing.

Brand registry and listing ownership deserve their own check. If the brand is registered under the seller's name, confirm the trademark and brand registry access can be transferred, and that you will control the listings after the sale. Without brand registry control, you cannot easily protect listings from hijackers or edit key listing content — a weakness that directly affects the value of what you are buying.

Keep a written due diligence file for the deal: the reports you reviewed, the questions you asked, and the answers you received. If a problem surfaces after closing, that file turns a vague complaint into a specific, documented claim — and it helps you run the business confidently from the first week, because you already know where its strengths and weak spots lie.