Most sellers run a mix of FBA and FBM. The choice per SKU is usually based on cost, weight, restrictions or strategic preference. What teams underestimate is how different the data looks across the two methods — and how that affects reporting, profit calculation and Account Health.

This guide breaks down the data differences and what to track for each.

TL;DR: FBA gives Amazon control over fulfillment and reporting is centralized through FBA-specific reports. FBM puts fulfillment on you, with shipment confirmation and tracking data flowing back to Amazon. Fees, performance metrics and inventory data differ across the two. A seller running both channels needs a data layer that reconciles them into one view of true cost and performance per SKU.

How FBA data works

FBA (Fulfilled by Amazon) means Amazon stores, picks, packs and ships your product. Amazon also handles customer service and returns for FBA orders.

FBA-specific data

• FBA Inventory — units by SKU, by warehouse, by marketplace, refreshed daily.
• Fulfillment fees — charged per unit shipped, varies by size tier.
• Storage fees — monthly per cubic foot, with peak season multiplier.
• FBA Returns — Amazon-handled returns with reason codes.
• Reimbursements — lost or damaged inventory reimbursements.
• Inbound shipments — status tracking from your warehouse to FBA.

What FBA hides from you

• Customer-level data unless you have restricted PII access.
• Specific warehouse routing decisions.
• Fulfillment timing variability.

How FBM data works

FBM (Fulfilled by Merchant) means you store, ship and handle customer service yourself. You confirm shipments through SP-API and provide tracking.

FBM-specific data

• Order data — you receive customer name, address (with restricted PII approval), order details.
• Ship-by dates — Amazon assigns each order a promise date you have to meet.
• Late Shipment Rate — metric Amazon tracks based on your ship confirmations.
• Pre-Fulfillment Cancel Rate — cancellations before ship.
• Valid Tracking Rate — percentage of orders shipped with usable tracking.
• Customer feedback and A-to-z claims — you handle them, you bear the metric impact.

What FBM gives you that FBA does not

• Direct relationship with the order — customer name, address, shipping path.
• Control over packaging and presentation.
• No FBA storage or fulfillment fees — you trade those for your own fulfillment costs.
• Faster inventory updates because you control them.

Where the metrics differ

Performance metrics

FBM is responsible for shipping performance metrics (Late Shipment Rate, Valid Tracking Rate, Pre-Fulfillment Cancel Rate). FBA shields you from these. Account Health for sellers running both is calculated only on the FBM portion of orders for these metrics.

Customer service metrics

Order Defect Rate applies to both, but FBA tends to drive lower ODR because Amazon handles returns and customer service. FBM ODR is more sensitive to your own ops quality.

Inventory metrics

FBA inventory has clear units-on-hand and aging data per warehouse. FBM inventory lives in your own systems — Amazon does not store it. Reconciling FBM inventory data has to come from your warehouse software.

Profit calculation differs

True margin per SKU has different components for FBA versus FBM:

• FBA margin = Revenue − referral fee − FBA fulfillment fee − storage − ad spend − COGS − inbound shipping
• FBM margin = Revenue − referral fee − your fulfillment cost (pick, pack, ship) — ad spend — COGS

An apples-to-apples profit comparison across the two channels requires consistent fee modeling on both sides.

Running both well

Sellers running both channels successfully:

• Track FBA and FBM as separate channels in their reporting, plus a combined view.
• Use FBM for high-margin or low-velocity items where FBA storage costs would erode margin.
• Use FBA for items that benefit from Prime eligibility and faster shipping.
• Reconcile inventory across both — customers do not care which channel ships.

The bottom line

FBA and FBM are not interchangeable from a data perspective. They have different fee structures, different metrics, different inventory systems and different reporting flows. Reporting across both means joining them into one coherent view.

DataDoe’s Amazon data layer ingests FBA and FBM data into one schema so true profit and performance comparisons across channels are queryable, not Excel work.