FBM (Fulfilled by Merchant)

FBM (Fulfilled by Merchant), sometimes called MFN (Merchant Fulfilled Network), is the fulfilment model where the seller handles every step from inventory storage to shipping. Amazon takes the order, collects payment, and forwards it; the seller ships it.

FBA vs. FBM trade-off

When FBM beats FBA economically

FBM is the better choice when:

• Oversize / heavy items where FBA fees consume the margin (large furniture, cast iron, dense liquids)
• Slow-moving SKUs where FBA storage fees compound month after month
• Hazmat items Amazon does not accept
• Custom or personalised products (engravings, made-to-order)
• B2B bulk pallets that ship direct from the seller's facility
• Backup inventory to keep the listing live when FBA stocks are in transit

FBM and the Buy Box

An FBM offer at the same price as an FBA offer almost always loses the Buy Box. The algorithm weights Prime eligibility heavily. To compete on Buy Box with FBM, either:

1. Enrol in Seller Fulfilled Prime (SFP) — earns the Prime badge with seller-shipped orders
2. Price below the FBA offer enough to offset the Prime preference
3. Be the only offer (private-label brand listings)

Common mistakes

• Defaulting everything to FBA. Some SKUs lose money on every FBA order due to fee structure.
• FBM without service level commitment. Late shipments crater account health.
• FBM as a "backup" without ever activating it. Build the workflow before you need it.
• Comparing FBA "all-in cost" to FBM "shipping only." Include your storage, your labour, your returns processing.