Amazon FBA Shipping, Explained With Real Numbers

Two shipping questions hiding inside one search term

"Amazon FBA shipping" is usually two different cost lines, and mixing them up is why sellers get surprised by their bill.

• Shipping to FBA (inbound): getting your inventory from your supplier or warehouse into Amazon's fulfillment centers. You pay this — to a carrier, a freight forwarder, or through Amazon's own partnered carrier program.
• FBA shipping (outbound): Amazon picking, packing and delivering the order once it sells. This is the fulfillment fee, and Amazon sets it based on the product's size tier and weight, not on distance to the customer.

The two move independently. You can lock in cheap inbound freight and still get hit by a fulfillment fee increase because a product got reclassified into a bigger size tier during a packaging change. The rest of this page covers both, in the order a new shipment actually goes through them.

How inbound shipping to FBA actually works, step by step

The mechanics don't change much whether you're shipping one pallet or fifty:

• Create a shipping plan in Seller Central — the SKUs, quantities, and where you're shipping from.
• Prep and label — Amazon assigns prep requirements per product (poly bags, suffocation warnings) and every unit needs an FNSKU label before it ships, unless you're enrolled in a labeling exemption.
• Amazon assigns the destination — by default your shipment may get split across multiple fulfillment centers. You can pay for the inbound placement service to send everything to one location instead, trading a fee for less handling on your end.
• Choose a carrier — Amazon's Partnered Carrier program (discounted UPS or freight rates booked through Seller Central) or your own carrier or freight forwarder.
• Reconcile on receipt — Amazon logs units as they're checked in, box by box. This is where discrepancies between what you shipped and what Amazon says it received show up.

A worked example: what a shipment actually costs

These numbers are illustrative, not Amazon's live rate card — fees vary by category and change over time, so run your own SKU through the Revenue Calculator for a real figure. But the mechanics below are accurate and they're the part most explainer pages skip.

Say you sell a kitchen tool, 500 units a month, boxed at 12 x 9 x 3 inches and 14 oz — inside the standard-size tier, fulfillment fee roughly $4.00/unit. Your supplier switches to a slightly thicker retail box: 12 x 9 x 4 inches. That crosses into the next size bracket, and the fulfillment fee moves to roughly $6.50/unit. Nobody changed the product. Nobody changed the price. The box got half an inch deeper.

On 500 units a month, that's an extra $1,250 a month — about $15,000 a year — sitting inside a fee line most sellers only glance at once a quarter. Storage cost moves too, since it's billed on the cubic feet the inventory occupies, not the unit count.

The mistake that costs the most: dimensional weight misclassification

Of everything in this article, this is the one worth remembering: a size-tier reclassification is silent. Amazon doesn't send an alert saying "your box got bigger, your fee changed." It just charges the new rate starting with the next shipment that measures into it, and it stays that way until someone checks.

Full Circle has managed more than $500M in revenue across 100+ brands, and this is one of the recurring findings when we open a fee review — a packaging change, a supplier swap, or a repack for a bundle that nudged a product's measured dimensions across a tier boundary months earlier, still billing at the new rate with nobody having gone back to look.

The honest caveat: this happens to people running fee audits professionally too, including us. The fix isn't a one-time check — it's a standing habit of re-measuring anything that's had a packaging change, a supplier switch, or a bundle added, before assuming last quarter's fee is still this quarter's fee.

When the received quantity doesn't match what you shipped

If Amazon's fulfillment center reports receiving fewer units than your carrier's bill of lading or your own count, that's a shipment discrepancy — not automatically a lost cause, but it does have a filing window, and Amazon won't chase it down for you.

• Pull the shipment reconciliation report in Seller Central and compare box-by-box, not just the total.
• Keep the paper trail — carrier proof of delivery, packing lists, photos of the sealed shipment before pickup. Without it, a discrepancy claim is a guess against Amazon's count.
• File before you're told it's closed — reimbursement and discrepancy claims work on a clock, and the window closes whether or not you've noticed the shortfall yet.

If the shortfall turns out to be a demand-planning problem instead — you keep running out before the next shipment lands, and rank drops mid-campaign as a result — that's a different fix, and it's worth separating the two before you spend time on either.

Where this fits: 3PLs, freight forwarders, and the fee side

Worth being precise about what each of these actually is, because the terms get used loosely. A 3PL physically stores your inventory and ships it — either to Amazon as your inbound partner, or direct-to-consumer outside Amazon. A freight forwarder moves goods internationally and gets them to a port or to Amazon's dock; that's a different job again. Neither one watches your fee lines for you, and neither one is what Dr. Stock does.

Dr. Stock doesn't move boxes. It's a managed service, run by Fable 5 out of Full Circle, that watches the numbers around the boxes: reorder timing before a stockout kills rank, cash trapped in slow SKUs, storage and aged-inventory surcharges, the removal-versus-liquidation call, fulfillment fee errors like the dimensional-weight case above, and reimbursement recovery on shipment discrepancies. Purchasing decisions always go through a human, whatever autonomy level a client sets, and Orbit — inventory, finance, and ASIN-level trackers — comes with it at no extra cost. If the leak you're chasing is in the ad account rather than the warehouse, that's a job for Dr. PPC, not this. There's no published price; it's a demo and a 30-day free window, priced on the call.