Amazon FBM (Fulfilled by Merchant) lets you ship your own Amazon orders without using FBA. Done right, it protects your margins, gives you carrier flexibility, and keeps you off the FBA fee treadmill. Done wrong, it tanks your seller metrics and gets your listing suppressed.
The three metrics that matter for FBM
- On-Time Delivery Rate (OTDR): Must stay above 95%. This is calculated from customer-reported delivery times, not just your shipping confirmation. A carrier delay on your end can hurt your OTDR even if you shipped on time.
- Late Dispatch Rate: Must stay below 4%. This is the percentage of orders where you didn't confirm shipment (upload tracking) within your stated handling time.
- Valid Tracking Rate: Must stay above 95%. Amazon requires tracking numbers that actually show carrier acceptance scans — not just numbers you made up.
The most common FBM metric mistake: Late tracking submission. If you ship on time but don't upload the tracking number to Amazon within your handling window, it counts as a late shipment. Automatic tracking submission eliminates this risk entirely.
Carrier selection for FBM
Amazon FBM allows any carrier. Your choice should be based on:
- OTDR risk: USPS has the highest delivery delay rate of the major carriers. For high-value or time-sensitive orders, FedEx or UPS reduces OTDR risk.
- Cost: USPS Ground Advantage wins for under 1 lb. UPS or FedEx Ground wins for heavier packages on Zone 5+ routes.
- Delivery promise: Amazon calculates your delivery promise based on the carrier and service you select. Choosing a slower service type than necessary increases OTDR risk.
Using Amazon Buy Shipping
Amazon Buy Shipping is the recommended approach for FBM. Labels purchased through Buy Shipping provide A-to-Z claim protection — if there's a carrier issue, Amazon covers it, not you. LogixVast connects to the Amazon Buy Shipping API directly, so you can rate shop multiple carriers within the Buy Shipping program.
The software setup
The workflow for FBM shipping should be: orders sync → rate shop → label generates → tracking submits to Amazon → done. Any manual step in that chain introduces late submission risk. LogixVast automates the entire chain via the Amazon SP-API.