FBA prep is everything you do to a unit before it ships to an Amazon fulfillment center: labeling it, packaging it to Amazon's spec, and boxing it so it survives the trip and scans clean on arrival. Get it right and your inventory checks in fast. Get it wrong and Amazon can refuse the shipment, charge a fee to fix it, or park your units in a hold that stalls your sell-through. This checklist walks the seven steps in order, from the ASIN-level prep check to the moment your boxes leave the dock.
What FBA prep actually is Amazon receives millions of units a day, so it standardizes how every unit arrives. Prep is the work that makes a unit ready to receive: a scannable barcode, packaging that matches the product category, and a shipment plan that tells Amazon what is in each box. Some products need almost nothing. Anything fragile, liquid, sharp, or sold as a set needs specific handling before Amazon will accept it. Those requirements live in Seller Central and Amazon updates them, so treat this checklist as the shape of the work and confirm the current spec for your products before you ship.
The biggest change for 2026 is who does the work. Amazon ended its optional US FBA prep and labeling service on January 1, 2026 , so every unit now arrives prepped by you or by a prep partner you hire. If a unit shows up with missing or improper prep, Amazon staff say it gets flagged as a defect and the prep or label is applied at receiving, which is corrective handling for a flagged unit, not a service you can book.
The FBA prep checklist Here are the seven steps, in the order you do them:
Verify your ASIN's prep requirements in Seller Central Label each unit with the barcode Amazon requires Package each unit to Amazon's category spec Bundle and label multi-pack units Build the shipment plan in Seller Central Prep the cartons and apply box content labels Ship to the fulfillment center Amazon assigns Step 1: Verify your ASIN's prep requirements in Seller Central Start in Seller Central, not with the tape gun. Open the product in Manage Inventory or the Send to Amazon flow and check the prep guidance and labeling settings for that ASIN. Amazon tells you which prep category applies, such as poly bagging, bubble wrap, a suffocation label, or bundling. Applying that prep, and the FNSKU when your unit needs one, is on you or your prep partner, because Amazon no longer offers prep or labeling services for US FBA. Checking first means you buy the right materials once and prep the whole batch the same way.
Step 2: Label each unit with the barcode Amazon requires Every unit needs a scannable barcode Amazon can tie to your listing, and which barcode depends on who you are. Since commingling ended on March 31, 2026, resellers must apply an FNSKU label to every unit even when it already carries a manufacturer barcode, while brand owners with the Brand Representative role in Brand Registry can keep shipping on the manufacturer barcode when the product has one, per Amazon's announcement ending commingling . The same announcement says a product with no manufacturer barcode needs an FNSKU from either kind of seller. When you apply an FNSKU, place it over the existing manufacturer barcode so only one scannable code shows. Print on thermal or laser labels that will not smear, and set each label flat on a scannable surface. A unit with a missing or unreadable barcode label gets flagged as a defect at receiving, and Amazon staff say a unit that turns untraceable in the warehouse because of a missing or defective label is not eligible for reimbursement.
Step 3: Package each unit to Amazon's category spec How you package a unit depends on what it is. Poly-bagged items like apparel and soft goods need a transparent bag, and Amazon's prep guide makes an exception only for adult products and items Amazon specifies for opaque bagging. Any bag with an opening of 5 inches or more needs a printed suffocation warning. Fragile and glass items need enough bubble wrap to pass Amazon's drop test. Sharp items need to be covered so they cannot puncture the packaging or a person. Liquids need a secure seal. When in doubt, over-protect, because a damaged unit at check-in is a loss, not a return.
Step 4: Bundle and label multi-pack units If you sell a two-pack, a set, or a kit, Amazon has to treat it as one sellable unit. Bundle the pieces so they cannot separate in transit, then label the outside "Sold as Set" or "Do Not Separate" so a warehouse associate does not split them. Bundle before you apply the FNSKU, so the barcode lands on the finished unit and not on a loose component.
Step 5: Build the shipment plan in Seller Central Once units are labeled and packed, create the shipment in Seller Central. You tell Amazon what you are sending and how many, and Amazon assigns which fulfillment center each SKU ships to. You do not get to pick. Amazon may split a single shipment across multiple FCs, so print the shipment ID and plan for more than one destination when the tool tells you to.
Step 6: Prep the cartons and apply box content labels Pack units into sturdy shipping cartons that can take a 3-foot drop. Keep each standard carton within Amazon's FBA box limits of 36 inches on the longest side, 25 inches on the other two sides, and 50 pounds, a length cap Amazon raised from 25 inches on June 20, 2025 according to its announcement . Use a "Team Lift" label when a single oversize unit pushes a box past the weight limit. If you inbound to Amazon Warehousing and Distribution instead, Amazon staff in the same thread say AWD boxes still have to stay within 25 by 25 by 25 inches and 50 pounds. Add box content information through the Seller Central tool or a manual box-content workflow so Amazon knows what is inside each carton, then apply the FBA shipment label and the carrier label to the outside.
Step 7: Ship to the fulfillment center Amazon assigns Book the carrier through Amazon's partnered program or your own account, hand off the boxes, and keep the tracking. Receiving usually takes a few days once the shipment arrives. Watch the shipment in Seller Central for receiving discrepancies, and reconcile anything that comes up short so you are not paying to store units Amazon never logged.
What happens when prep is wrong Amazon does not quietly fix bad prep for free. A missing FNSKU, a poly bag with no suffocation label, or an unbundled set can trigger an unplanned-prep or labeling fee, a receiving delay while the unit sits in a problem queue, or a refused shipment sent back at your cost. For a seller running lean on cash flow, a shipment stuck in receiving is inventory you already paid for that you cannot sell. The checklist above exists to keep your units out of that queue.
When to use an FBA prep center Prepping a few dozen units at your kitchen table is fine. Prepping a few thousand across several categories, on a deadline, before a restock window closes, is a different job. That is when sellers hand prep to a third party.
An Amazon 3PL receives your bulk inventory, applies FNSKU labels, packages each unit to Amazon's spec, builds the shipment plans, and forwards the boxes to the assigned fulfillment centers. It can also ship your FBM and direct-to-consumer orders from the same inventory, so you are not splitting stock across two warehouses.
Simpl runs Amazon FBA prep as a core service from its Austin, TX warehouse: units labeled, packaged to category spec, and inbounded to Amazon. Orders received before 12pm CT ship the same day, and Simpl's order accuracy is 99.99%, with errors corrected at Simpl's cost, return shipping and re-fulfillment included. The same Austin warehouse offers ecommerce order fulfillment alongside FBA prep, so one 3PL can cover both. Talk to us to scope your SKUs.
