The Complete FBA Shipment Guide

How an FBA shipment plan works

Every FBA shipment starts as a shipment plan inside Seller Central's Send to Amazon workflow. You select the SKUs and quantities you want to send, declare your packing approach (individual units vs. case-packed identical boxes), tell Amazon the dimensions and weight of each box, and Amazon responds with one or more shipments — each destined for a specific fulfillment center, each with its own shipment ID.

The key mental model: you create a plan, Amazon creates the shipments. A single plan for 600 units of one SKU might come back as one shipment to one FC, or as four shipments to four different FCs, depending on the placement option you pick and Amazon's current network needs. Each resulting shipment gets a unique shipment ID (format FBA followed by alphanumerics) that drives box labels, carrier booking, and later reconciliation.

There are two packing templates. Individual units (mixed SKUs and quantities per box) is flexible but labor-heavy and forces you to enter exact box contents. Case-packed products means every box of a given SKU is identical — same SKU, same quantity, same configuration — which is faster to declare, scans cleanly, and is the format Amazon rewards with the cheapest placement options. If your supplier ships you sealed master cases, case-packed is almost always the right template.

Before you build a plan, confirm the SKU is eligible: it must have a product listing, a valid barcode setting (Amazon barcode/FNSKU vs. manufacturer barcode), and must not be blocked by your restock limits or capacity limits. SellerVault surfaces these constraints next to each recommended buy so you don't build a plan Amazon will reject at submission.

The inbound placement service fee — and how to minimize it

On March 1, 2024, Amazon introduced the FBA inbound placement service fee for standard-size and large bulky-size products. The fee exists because Amazon, not you, often wants your inventory spread across multiple regional fulfillment centers so it's close to customers. When you refuse to do that spreading work yourself, Amazon does it for you and charges you per unit.

In Send to Amazon you choose one of three split options, and the option directly sets the fee:

• Amazon-optimized splits — you send to the multiple inbound locations Amazon recommends. This is the cheapest path and can reduce the fee to $0 when you spread inventory across enough destinations (sending to roughly four or more recommended centers can eliminate it). To qualify for the no-fee version, each item must ship as at least five identical cartons or pallets, every carton holding the same quantity and item mix.
• Partial splits — fewer destinations than Amazon ideally wants; a reduced per-unit fee.
• Minimal splits — you consolidate to the fewest locations (often one), and pay the highest fee in exchange for the lowest freight and labor on your end.

The per-unit fee depends on size tier, weight, and how minimal your split is. As of the current schedule, standard-size products run roughly $0.21-$0.44 per unit; large bulky items run roughly $1.50-$2.10 per unit. Effective January 15, 2025, Amazon reduced the large-bulky fee by an average of $0.58 per unit for minimal splits.

The right choice is a math problem, not a default. Minimal splits cost more in placement fees but save real money on freight (one destination, fewer LTL stops, simpler labor). For a low-cost, high-volume standard SKU, paying $0.30/unit to ship one consolidated truck can beat the freight and handling of four destinations. For a heavy bulky SKU at $2/unit, the optimized spread usually wins. Two ways to skip the fee entirely: enroll in Amazon Warehousing & Distribution (AWD), where placement is an included service, or qualify under FBA New Selection promotions that waive the fee on initial units of new ASINs. Always compare the placement-fee delta against your freight quote before you confirm the plan — the cheapest button on screen is rarely the cheapest landed cost.

Prep requirements by product category

Prep is the physical preparation a unit needs to survive Amazon's fulfillment network and reach a customer intact. Amazon publishes prep guidance across roughly a dozen product categories, and getting it wrong gets units relabeled as unfulfillable — or gets your account hit with an unplanned-prep service fee.

Poly-bagging is the most common requirement. Bags must be at least 1.5 mil thick, transparent, and sealed. Any bag with an opening of 5 inches or wider (measured flat) must carry a printed suffocation warning reading exactly: 'WARNING: To avoid danger of suffocation, keep this plastic film away from babies and children.' The barcode must remain scannable through the bag.

Fragile and liquid items need protection that passes Amazon's 3-foot drop test — five consecutive drops (flat base, top, longest side, shortest side, and a corner) with no damage. Bubble wrap should fully enclose the product with at least two layers and no exposed surface. Sharp items must be guarded so they can't cut a picker. Adult products require opaque (black) bagging.

Expiration-dated and topical/consumable products carry the strictest rules: the date must be printed clearly enough for an associate to read, in lot-coded format, and the unit must arrive with at least 105 days of remaining shelf life from the date it reaches the FC. Sets and bundles must be marked 'sold as set' so Amazon doesn't split them. When in doubt, open the SKU's prep guidance in Seller Central rather than guessing — prep mistakes are quietly expensive and compound across every unit in the shipment.

FNSKU and unit labeling

Most FBA units need an FNSKU label — the Amazon-specific barcode that ties a physical unit to your seller account and listing. You choose between two barcode modes per SKU: the Amazon barcode (FNSKU), where you cover the manufacturer barcode with an FNSKU and your inventory is stored separately (recommended for most private-label and resale sellers), or the manufacturer barcode (commingled), where Amazon uses the existing UPC/EAN and may fulfill your order from another seller's identical stock. Commingling removes the labeling step but exposes you to other sellers' inventory quality — most operators choose FNSKU labeling.

FNSKU label specs are exact. Print in black ink on a white label, sized 1-2 inches tall by 2-3 inches wide, with white space around the barcode (about 0.25 in on the sides, 0.125 in top and bottom). The label must include a scannable barcode, the FNSKU number, the product title, and the condition ('New' or used). Thermal labels are fine if they scan reliably.

Apply the FNSKU so it covers any existing manufacturer barcode — two scannable barcodes on one unit causes scan ambiguity and misrouting. On poly-bagged items, the FNSKU goes on the outside of the bag and must scan through it. For bundles and multi-packs, label the outer packaging once and mark it so the set isn't broken apart.

Get labeling right at the source. The cheapest place to apply FNSKU labels is at your supplier or 3PL prep partner before the units ever reach your hands — Amazon's own FBA Label Service charges per unit and is rarely worth it at volume. A single mislabeled SKU can strand an entire shipment in receiving while Amazon researches it.

Box content information and 2D barcodes

Amazon must know exactly what is inside every box before it arrives. Box content information — the SKU-by-SKU, quantity-by-box manifest — is mandatory, and it is the single most common reason boxes get stuck in receiving when it's missing or wrong.

You can provide box contents three ways: manual entry in Send to Amazon (or by uploading the box-content spreadsheet/flat file), an automated feed via the SP-API integration, or 2D barcodes printed on each box that encode the contents. Counterintuitively, Amazon warns that 2D barcodes can slow receiving — boxes with 2D barcodes require more processing time than boxes whose contents were uploaded ahead of arrival. For most sellers, uploading box contents in the workflow (manually or via API) is faster end-to-end than printing 2D barcodes.

Every box ends up with up to three distinct labels, and they are not interchangeable: the FBA box ID label (the shipment/box identifier Amazon generates), the carrier shipping label (UPS/FedEx/partnered carrier), and — if you didn't pre-upload contents — the box content identifier. Mixing these up, or reusing a box ID across two physical boxes, breaks reconciliation.

Accuracy here pays you back at the end. The box content manifest is the baseline Amazon receives against. If you declare 24 units in box 3 and Amazon scans 22, that two-unit gap becomes a reconciliation discrepancy you can claim. If your manifest was sloppy, you have no leg to stand on. Treat box content information as your reimbursement insurance policy, not a formality. SellerVault's shipment wizard builds the box-content manifest as you pack so the declared counts match the physical reality you can later prove.

Packing, box limits, and oversize rules

Amazon enforces hard physical limits on inbound boxes, and exceeding them triggers rejections or non-compliance fees. As of the current rules (effective June 20, 2025), a standard shipping box may be up to 36 in (L) x 25 in (W) x 25 in (H) and must weigh 50 lb or less.

The weight cap has two exceptions, both tied to single-item boxes. A box may exceed 50 lb only if it contains a single oversized item (a unit that genuinely can't be split), and it must then carry the correct lift label on at least five sides. As a practical scale: 33-50 lb boxes should carry a 'Heavy Package' label as a courtesy/safety practice; over 50 lb (single oversized item) requires a Team Lift label; over 100 lb requires a Mechanical Lift label. Likewise, a box may exceed the 36-inch length limit only when it holds a single oversized item that can't be packed smaller (a yoga mat, pole, or tripod).

Pack to protect, not just to fill. Use a sturdy double-walled corrugated box, leave no rattling void (fill with dunnage), and never let units shift. Don't mix loose units and case packs in the same box unless your plan is built for individual-unit packing. Keep heavy items low and balanced. A burst box in transit becomes damaged inventory that Amazon may refuse — and a refused unit is lost revenue plus return freight.

For pallet (LTL/FTL) shipments, stack to Amazon's pallet spec: shrink-wrapped, not overhanging the pallet, generally within the 72-inch pallet height limit, with the required pallet labels (Amazon now requires pallet labels formatted as PDF417 barcodes for US FCs). Decide early — small parcel (SPD) for individual boxes, LTL/FTL for palletized volume — because it changes your carrier choice, labels, and appointment requirements.

Partnered carrier vs. non-partnered

Once boxes are packed and weighed, you choose how they travel. The decision is between an Amazon Partnered Carrier and a non-partnered carrier you book yourself.

Partnered carrier means Amazon's negotiated UPS (small parcel) or partnered LTL rates, billed through Seller Central and deducted from your account. The advantages are real: deeply discounted shipping, labels generated inside the workflow, and tracking that ties automatically to your shipment so receiving and reconciliation are tighter. For most small-parcel FBA shipments, partnered UPS is the path of least resistance and lowest cost.

Non-partnered carrier means you arrange your own freight (your own UPS/FedEx account, a regional LTL carrier, or a freight forwarder) and enter the tracking/PRO number manually. You'd choose this when you have better-negotiated rates than Amazon's partnered program, when shipping internationally into the US, or for specialized freight. The tradeoff: you own the booking, the labels, the delivery appointment, and any failed-delivery risk. With non-partnered freight, set realistic delivery windows in Send to Amazon — understating the window creates receiving bottlenecks and can delay your inventory going live.

Whichever you pick, the carrier label and the FBA box ID label must both be on every box and must agree. Book LTL appointments where the destination FC requires them. The partnered-vs-non-partnered choice is mostly about who has the cheaper rate and who you want owning the exception handling — run the actual quote both ways for any shipment large enough to matter.

Receiving, reconciliation, and reimbursements

Your job isn't done when the boxes ship — it's done when Amazon's received quantity matches what you sent, or you've been reimbursed for the gap. After delivery, units move through Amazon's receiving process over days (sometimes weeks during peak), and the shipment's received count climbs toward your shipped count.

Watch for three failure modes. Shortages: Amazon checks in fewer units than your box content manifest declared. Lost in transit / in receiving: units scanned by the carrier but never reconciled into your inventory. Damaged on receipt: units Amazon deems unfulfillable through no fault of your packing. Each is potentially reimbursable — but only if your manifest was accurate and you file within Amazon's claim window.

Reconciliation is mechanical: compare declared vs. received at the SKU and box level, identify the discrepancy, gather the proof (box content manifest, carrier proof of delivery, supplier invoice showing unit cost), and open a reconciliation case. Amazon will often ask you to prove ownership and quantity, which is exactly why the box content information and a clean shipment manifest matter so much. Don't let cases sit — claim windows expire, and an unfiled shortage is simply money you gave Amazon.

This is where operations-first tooling pays for itself. SellerVault watches every shipment's received-vs-declared delta, flags shortages and damage automatically, assembles the evidence pack, and surfaces the reimbursement before the claim window closes — turning reconciliation from a quarterly fire drill into a standing recovery process. Combined with demand-forecasted restock planning that builds the next shipment plan from real coverage and lead times, the full loop — buy, ship, reconcile, recover — runs without you babysitting spreadsheets.