FBA vs. FBM: Which Fulfillment Method Is Best for Your Business?
If you sell on Amazon, you have faced the same fork in the road: fulfil orders yourself, or hand inventory over to Amazon and let them do it. The decision affects your margin, your Prime badge, your cash flow, and how much of your week you spend at the post office. This guide gives you the numbers and the logic to make the right call for your specific products — especially as a Canadian seller shipping cross-border.
What FBA and FBM Actually Mean
FBA (Fulfilled by Amazon) means you send your inventory to Amazon's fulfillment centres (FCs) in bulk. When a customer orders, Amazon picks, packs, ships, and handles returns — you never touch the parcel. Your listings automatically qualify for Prime two-day delivery.
FBM (Fulfilled by Merchant) means you keep stock at your own location (or a third-party warehouse), and ship each order yourself when it comes in. You control packaging, carriers, and the customer experience. Prime is available through Seller Fulfilled Prime (SFP), but the performance bar is extremely high.
The Cost Breakdown
Neither model is universally cheaper. The math changes with product size, weight, velocity, and your storage duration.
| Cost Factor | FBA | FBM |
|---|---|---|
| Fulfillment fee | Amazon charges per unit (~$3–$6+ for standard size) | You pay postage + packaging materials |
| Storage | Monthly fee per cubic foot; surcharges Oct–Dec | Your warehouse / your home / 3PL cost |
| Labour | Included in Amazon fees | Your time or staff wages |
| Returns | Amazon handles; some items get disposed | You inspect and restock yourself |
| Prep costs | Required (FNSKU labels, poly bags, etc.) | Minimal — only standard carrier packaging |
The honest takeaway: FBA fees look high in isolation, but they replace real labour, real warehouse rent, and real shipping account overhead. For most sellers moving more than 100 units per month, FBA delivers better unit economics once you stop counting only Amazon's line items.
The Prime Badge: Why It Moves the Needle
Prime members (the majority of Amazon's highest-spending customers) filter by Prime by default. A listing without the Prime badge is invisible to a large slice of buyers before you even compete on price. Studies consistently put the Prime conversion lift at 20–30% on equivalent listings.
FBA gives you Prime automatically. FBM sellers can apply for Seller Fulfilled Prime, but you must maintain a 99%+ on-time shipment rate, same-day handling, and national carrier coverage — requirements most small operations cannot sustain without significant investment.
When FBM Actually Wins
FBM is the right call in specific situations:
- Oversized or heavy items — Amazon's FBA fees scale steeply with size and weight. A 100 lb. piece of furniture may be far cheaper to ship direct to the customer via freight than to pay FBA's oversize fees plus monthly storage.
- Slow-moving inventory — If a SKU sells fewer than 5 units per month, long-term storage fees (charged after 365 days) can destroy margin faster than any other cost line.
- Hazardous or restricted goods — Many products are restricted at Amazon FCs. FBM is often the only option.
- Custom or made-to-order products — If every order is unique, central inventory holding does not make sense.
- High-volume, low-competition niches — If your niche has loyal buyers who search specifically for you, the Prime premium matters less.
The Canadian Seller Angle
Selling from Canada adds a layer of complexity. Amazon.ca's FC network is smaller than the US network, so inventory often needs to ship cross-border to US FCs for .com listings. That means:
- Customs brokerage on inbound shipments to US FCs
- Currency conversion on fees and payouts
- GST/HST registration requirements as your volume grows
This is where an Ottawa-based prep center changes the equation. Rather than managing US customs on every inbound shipment yourself, a prep center like Nectar Prep receives your goods domestically, handles all Amazon prep requirements (FNSKU labelling, poly bagging, inspection), and ships compliant pallets or cartons directly to Amazon FCs — US or Canadian — on your behalf.
A Practical Decision Framework
- Run the FBA revenue calculator on your top 5 SKUs. Amazon's free tool gives you an exact fee breakdown. Compare against your current shipping + storage + labour cost per unit.
- Check your sell-through rate. If inventory regularly sits more than 6 months, the storage fee math shifts toward FBM.
- Assess your operational bandwidth. If you or your team are spending more than 10 hours per week on packing and shipping, FBA frees that time for sourcing, marketing, and growth.
- Consider a hybrid approach. Many experienced sellers use FBA for their top 20% of SKUs (fast movers that benefit most from Prime) and FBM for the long tail.
The Bottom Line
FBA is not right for every product, but it is right for most fast-moving standard-size SKUs where Prime conversion and hands-off fulfilment outweigh the fee structure. FBM is right for oversized, slow-moving, or restricted goods. The best sellers run both — and use a prep center to make sure every inbound shipment to Amazon is compliant, accurate, and processed in days rather than weeks.
If you are a Canadian seller trying to work out the math for your catalogue, our team at Nectar Prep can walk you through it. We have prepped thousands of shipments and know exactly where the FBA/FBM break-even sits for different product categories.