Published June 28, 2026 · Updated June 28, 2026 · 7 min read
When you start selling on Amazon, one of the first decisions you'll make is how to fulfill orders: let Amazon handle it (FBA) or do it yourself (FBM). Both are legitimate strategies, and choosing the wrong one for your product can cost you thousands of dollars a year. Here's how to decide.
Fulfillment by Amazon (FBA) means you ship your inventory in bulk to Amazon's warehouses, and Amazon picks, packs, and ships each order to the customer. Amazon also handles customer service and returns for FBA orders.
In exchange, Amazon charges:
Fulfillment by Merchant (FBM) means you store inventory yourself (at home, in a 3PL warehouse, or a rented space) and ship each order directly to customers after a sale.
With FBM you pay:
| Factor | FBA | FBM |
|---|---|---|
| Prime badge | ✅ Automatic | ❌ Only via SFP |
| Shipping speed | 1–2 days (Prime) | Depends on your carrier |
| Customer service | Amazon handles it | You handle it |
| Returns | Amazon handles it | You handle it |
| Fulfillment fee | $3.06–$89.98+ per unit | $0 (you pay shipping) |
| Storage fee | $0.87–$2.40 per cu ft/mo | $0 (you pay warehouse) |
| Best for | Small, fast-moving items | Heavy, slow, or large items |
FBA fulfillment fees are calculated by size tier. Small standard items (under 16 oz, fitting in a 15"×12"×0.75" box) pay just $3.06–$3.33 per unit. For a $30 product, that's about 10% of selling price — often cheaper than what you'd pay a 3PL or shipping yourself.
Prime members convert at 3–4× the rate of non-Prime listings. If your competitors are on FBA and you're not, you're fighting an uphill battle on conversion rate. The Prime badge alone often justifies FBA fees for competitive categories.
Fast-selling products minimize storage fees. If you're turning over inventory every 30–60 days, storage costs are negligible. FBA shines when your product moves quickly and the fulfillment fee is a small percentage of your selling price.
FBA is the most capital-efficient way to scale. You don't need a warehouse team, shipping software, or carrier accounts. Amazon's infrastructure handles everything from receiving to delivery to returns at a per-unit cost that's hard to beat at low volumes.
FBA fulfillment fees for oversize items start at $9.61 and can exceed $89.98 per unit. For a 10 lb item you can ship via UPS Ground for $8–12, FBM is clearly cheaper. Heavy products where your own shipping rate beats Amazon's fulfillment fee are the classic FBM use case.
If your inventory sits in Amazon's warehouse for 90+ days, storage fees accumulate fast. At $0.87/cu ft/month for a slow mover, and $2.40/cu ft in Q4, a large product that sells every few weeks can rack up more in storage than it makes in profit. FBM eliminates this risk entirely.
If you're already fulfilling Shopify, Walmart, or other orders from your own warehouse, adding Amazon FBM is nearly zero marginal cost. You're already paying for the space and labor.
In highly competitive categories where margins are under 15%, FBA fees can wipe out profit entirely. FBM gives you more control over costs, especially if you have negotiated rates with UPS, FedEx, or USPS.
Many experienced sellers use both methods simultaneously:
This hybrid approach gives you Prime conversion on your main SKUs while keeping storage fees in check on the long tail.
The only way to know for certain is to run the numbers for your specific product. The key formula:
FBA Profit = Sale Price − Referral Fee − FBA Fulfillment Fee − Storage Fee − COGS − Shipping to Amazon FBM Profit = Sale Price − Referral Fee − Your Shipping Cost − Warehouse Cost − COGSCalculate your FBA profit now
Enter your sale price, COGS, and FBA fees to see your actual net profit and margin.
Open FBA Profit Calculator →Seller Fulfilled Prime lets you display the Prime badge while shipping orders yourself — but the requirements are strict:
SFP works for sellers who already have fast, reliable shipping infrastructure (large 3PLs, existing direct-to-consumer operations). For most small sellers, it's operationally demanding and FBA remains the easier path to Prime eligibility.
It depends on product size and velocity. FBA wins for small, fast-moving items where Prime eligibility drives conversion. FBM wins for heavy, oversized, or slow-moving products where FBA storage and fulfillment fees eat into margins.
Yes — a hybrid approach is common. Use FBA for your main fast-moving SKUs and FBM as a backup or for slow movers you don't want stored in Amazon's warehouse.
Standard FBM listings do not. Seller Fulfilled Prime (SFP) is the exception — it grants the Prime badge to FBM sellers who meet Amazon's strict shipping performance criteria.
FBM sellers pay the referral fee (8–17% by category) and the $39.99/month Professional plan. There are no FBA fees, but you cover your own shipping and storage costs.