What Amazon FBA Prep Actually Involves
FBA prep is everything that happens between your products arriving from a supplier and those products being accepted into Amazon's fulfillment network. It is not one task. It is a sequence of compliance steps, and each step has specific requirements published in Amazon Seller Central.
At its simplest, prep includes three things. First, every unit needs a single scannable barcode, typically an FNSKU label, placed correctly and covering any conflicting barcodes. Second, every unit needs appropriate physical protection: a sealed poly bag, bubble wrap, a rigid box, or a combination, depending on the product type. Third, every unit must be packed into a shipment carton that matches the plan created in Seller Central, with accurate box content information and the correct shipping label applied.
Beyond those basics, specific products require additional steps. Products sold as sets need "Sold as Set" or "Do Not Separate" labels. Items with expiration dates need legible date markings and sufficient remaining shelf life. Fragile products need packaging that can survive a three-foot drop test. Liquids need leak-proof containment. Each of these category-specific requirements adds a prep step that must be completed before the shipment leaves your control.
The full process also includes receiving inventory from your supplier, inspecting it for damage or defects, and verifying unit counts against your records. A unit that passes inspection but gets a wrong FNSKU label is just as non-compliant as a unit that was never prepped at all.
What Changed in 2026
Amazon Discontinued Internal Prep Services
On January 1, 2026, Amazon ended its FBA Prep Service in the United States. Before this date, sellers could pay Amazon a per-unit fee to handle labeling, poly bagging, bubble wrapping, and other prep tasks at the fulfillment center. That option no longer exists for US shipments.
The practical impact is straightforward. Every unit that previously relied on Amazon to apply an FNSKU label, bag it, or wrap it must now arrive at the fulfillment center fully prepped. Non-compliant units trigger per-unit inbound defect fees instead of being quietly corrected. Sellers who relied on Amazon's service must now either build an in-house prep operation or work with a third-party prep center.
Shipments that were created in Seller Central before January 1, 2026, could still receive prep services even if they arrived at the fulfillment center after the cutoff. That grace period has passed.
The End of Commingled Inventory
Amazon also ended its commingled inventory program, sometimes called stickerless inventory, on March 31, 2026. Under the previous system, sellers could send products to FBA using only the manufacturer barcode (UPC, EAN, or ISBN). Amazon would pool identical products from multiple sellers in the same bin and fulfill orders from the shared stock.
That system is gone. After March 31, 2026, every unit shipped into FBA must carry a seller-specific FNSKU barcode. Amazon no longer pools units from different sellers, and inventory that arrives without a properly applied FNSKU is treated as defective.
This change has the biggest impact on resellers who are not enrolled in Amazon Brand Registry. Brand owners registered in Brand Registry may still use eligible manufacturer barcodes under Amazon's current guidelines. Resellers and sellers without Brand Registry enrollment must apply an FNSKU to every unit.
How to Find Your Product's Prep Requirements
Amazon assigns prep requirements at the product level, and those requirements can change based on the category, condition, and damage history of the ASIN. The most reliable way to find what your specific products need is through the shipment creation workflow in Seller Central.
To check your requirements:
- Log into Amazon Seller Central and go to Inventory, then select Send to Amazon.
- Select the products you plan to ship and enter your quantities.
- In the shipment workflow, Amazon will display the required prep for each SKU. This includes whether the product needs poly bagging, bubble wrap, labeling, taping, or other handling.
- Confirm who is responsible for prep. Since January 2026, this defaults to the seller.
Amazon can also add prep requirements to a product retroactively based on damage-related customer returns. A product that only needed an FNSKU label last quarter may now require bubble wrap or overboxing because of reported transit damage. Checking requirements in the Send to Amazon workflow before each shipment, rather than relying on previous experience, is the reliable approach.
For products you are listing for the first time, Amazon's packaging and prep requirements page in Seller Central (help page 200141500) provides the general rules by product type. Category-specific requirements, such as apparel needing hangers removed, or supplements needing expiration dates, are listed in the same documentation.
Amazon's Prep Requirements by Product Category
Amazon's general prep rules apply to all FBA products, but several categories carry additional requirements. The table below summarizes the most common category-specific rules. Exact poly bag thickness, suffocation warning text, and drop test procedures are covered in detail in our Amazon FBA packaging requirements guide.
| Product Category | Key Prep Requirements |
|---|---|
| Apparel and soft goods | Remove hangers. Place each unit in a transparent, sealed poly bag (minimum 1.5 mil thickness). Bags with an opening of 5 inches or larger must include a suffocation warning. The FNSKU label must be scannable through the bag or applied to the outside. |
| Fragile and breakable items (glass, ceramics) | Wrap individually in bubble wrap or foam. The finished unit must survive a three-foot drop test onto a hard surface without breaking. May require overboxing. |
| Liquids, pastes, gels, and creams | Secure caps with tape or shrink wrap to prevent leaks. Place in a sealed poly bag as secondary containment. Units with flip-top or pump caps need extra attention, as pressure changes during transit can open them. |
| Products with expiration dates (supplements, food, beauty) | Print the expiration date legibly on the product and on the outside of any prep packaging. Amazon requires a minimum remaining shelf life at the time of receipt, typically 90 days or more depending on the category. Products with expiration-dated prep packaging (like poly bags) must show the date on the outside. |
| Sharp or pointed items | Fully cover the sharp edge or point so it cannot cut through outer packaging or injure a warehouse worker during handling. |
| Small or loose items | Products that could spill, scatter, or get lost during handling must be sealed in a poly bag or secured container. Loose hardware (screws, bolts, small parts) must be bagged. |
| Oversize and heavy items | Cartons containing oversize items must meet weight limits (50 lbs standard, with a "Team Lift" label required above 50 lbs). Products exceeding standard dimensions may need special palletization for LTL shipments. |
| Products sold as sets or bundles | All components must be physically grouped and secured. Label the set "Sold as Set" or "Do Not Separate." The set receives a single FNSKU. Individual items within the set should not have separate scannable barcodes. |
Amazon updates these requirements through Seller Central, and changes can happen without prominent announcements. Before a large production run, verify the current rules for your specific ASINs rather than relying on a previous shipment's settings.
FNSKU Labeling: What It Is and When You Need It
An FNSKU (Fulfillment Network Stock Keeping Unit) is a barcode that Amazon generates for your seller account and assigns to a specific product listing. It is what allows Amazon to track your inventory separately from other sellers offering the same product.
Since the end of commingled inventory in March 2026, FNSKU labeling is mandatory for nearly all FBA sellers. The exceptions are limited to brand owners enrolled in Amazon Brand Registry who are eligible to use manufacturer barcodes under Amazon's current policies.
The key labeling rules:
- Print FNSKU labels on white, non-glossy stock. Glossy surfaces cause scanner glare and receiving failures.
- Standard label size is approximately 1 inch by 2 inches or 1 inch by 3 inches.
- Place the label on a flat, non-curved surface where it will not be covered by tape, shrink wrap, or another label.
- Cover any existing manufacturer barcode (UPC, EAN, ISBN) completely so only the FNSKU is scannable.
- Each unit gets exactly one FNSKU label. Sets and bundles get one label for the entire set, not one per component.
FNSKU labels are generated through Seller Central's shipment creation workflow. You can download them as PDFs and print them on standard label sheets.
The FBA Prep Process Step by Step
Whether you handle prep yourself or use a prep center, the sequence follows the same logic. Each step depends on the one before it.
Step 1: Receiving and Inspection
Products arrive from your supplier. Count every unit against the purchase order or advance shipping notice. Inspect for damage, missing components, incorrect variants, and packaging that would not meet Amazon's standards. Flag problems before any labeling begins. A damaged unit that gets labeled and shipped will be rejected at Amazon, costing you the prep work and the return shipping.
Step 2: Labeling
Apply the FNSKU barcode to each unit, covering any existing manufacturer barcodes. For products with expiration dates, confirm the date is printed legibly on the outer packaging. For sets, apply the "Sold as Set" label and a single FNSKU for the group. This step must happen before packaging, because a label applied over a poly bag is harder to position correctly than one applied directly to the product.
Step 3: Packaging
Bag, wrap, or box each unit according to its category requirements. Apparel goes into sealed poly bags. Fragile items get bubble wrap and possibly an overbox. Liquids get leak-proof containment. Products that pass a visual inspection but would fail a drop test need additional protection.
Step 4: Bundling and Kitting
For multi-packs and kits, assemble the components, secure them together, and label the bundle as a single unit. Each bundle or kit gets its own FNSKU. Individual items inside the bundle should not have visible, scannable barcodes.
Step 5: Cartonization and Shipment Creation
Pack the prepped units into shipment cartons. Each carton must weigh under 50 lbs (unless it contains a single oversize item), and no side should exceed 25 inches for standard-size shipments. Generate box content information in Seller Central, print the shipping label and box content label for each carton, and apply both labels to flat surfaces where they will not be covered by tape or wrapping.
Step 6: Shipping to Amazon
Hand the shipment to the carrier specified in your Seller Central shipping plan. Record tracking information against the shipment. The completed cartons go directly to the Amazon fulfillment center or centers assigned in the plan. For small parcel shipments, carriers like UPS, FedEx, and the Amazon Partnered Carrier program handle the final leg. For larger volumes, LTL (less-than-truckload) or FTL (full truckload) freight moves palletized cartons.
Common FBA Prep Mistakes That Cause Rejections
Most shipment rejections come from a small number of repeated errors. These are the ones that show up most often at Amazon's receiving docks, based on industry reporting and published Seller Central guidance.
- FNSKU placed over a curve or seam. The label wrinkles, the barcode distorts, and the scanner cannot read it. Always place labels on flat surfaces.
- Old manufacturer barcode left uncovered. If Amazon's scanner picks up two barcodes, it may route the unit to the wrong inventory pool or reject it entirely. Cover every non-FNSKU barcode completely with a blank label or the FNSKU itself.
- Poly bag missing a suffocation warning. Any bag with an opening of 5 inches or larger requires the warning. Pre-printed FBA-grade bags eliminate this risk entirely. Generic bags from overseas suppliers often lack the required text.
- Poly bag below 1.5 mil thickness. Bags that are too thin tear during automated handling. Amazon will refuse units in sub-spec bags at receiving.
- Expiration-dated products with insufficient shelf life. Amazon's minimum shelf life requirement at the time of receipt is typically 90 days or more, depending on the product category. Products that clear your warehouse with 120 days remaining may arrive at Amazon with less than 90 days after transit delays. Build in a buffer.
- Carton weight exceeding 50 lbs without a heavy-item label. Standard cartons have a 50 lb limit. A carton that exceeds this without proper marking is a safety violation and gets flagged at the dock.
- Box content information missing or inaccurate. When the physical contents of a carton do not match the digital record in Seller Central, Amazon has to process the carton manually. This slows receiving and may result in additional charges.
What FBA Prep Costs
FBA prep costs vary based on whether you handle it yourself, use a prep center, or use a hybrid approach. The ranges below are general estimates based on publicly reported industry pricing, not Lite Fulfillment-specific rates.
DIY Prep Costs
If you prep in-house, your costs include materials (poly bags, FNSKU label sheets, tape, dunnage, bubble wrap), a thermal or laser printer, warehouse or storage space, and the labor time of whoever does the work. Material costs typically run between $0.15 and $0.50 per unit depending on the product type and packaging requirements. Labor is the variable that makes DIY prep expensive at scale: the time spent on labeling, bagging, inspecting, and cartonizing adds up quickly once you pass a few hundred units per shipment.
Prep Center Costs
Third-party FBA prep centers typically charge a per-unit fee that covers receiving, inspection, labeling, and basic packaging. Published industry rates generally fall in the range of $0.75 to $3.00 per unit, depending on the complexity of the prep (standard labeling on one end, multi-step bundling with poly bagging on the other). Most centers also charge receiving fees (per pallet or per carton), monthly storage fees, and outbound shipping to Amazon's fulfillment centers as separate line items.
The total cost of outsourced prep depends heavily on your SKU mix, volume, and how many prep steps each product requires. A single-SKU seller with simple products will pay less per unit than a multi-SKU seller with expiration tracking, bundling, and fragile-item handling.
When comparing options, account for the cost of rejection. A shipment that gets refused at Amazon because of a labeling error costs you the return freight, re-prep labor, and the lost selling days while inventory sits in transit. For most growing sellers, the break-even point where outsourcing becomes less expensive than doing it yourself arrives earlier than expected.
When to Outsource FBA Prep
The decision depends on your volume, the complexity of your product catalog, and whether prep is pulling time away from higher-value work like product development, sourcing, or marketing.
Self-prep works well for sellers with fewer than 10 SKUs, simple prep requirements (labeling only), available space and staff, and consistent time to dedicate to the process. Once your catalog grows, your products require poly bagging or bundling, your volume fluctuates seasonally, or you are importing goods from overseas, the operational burden of in-house prep often exceeds what a prep center would charge.
If you reach that point, our breakdown of how to choose the right FBA prep center walks through what to check on pricing, turnaround, accuracy, and communication before committing. Lite Fulfillment handles FBA prep from our warehouse in Delaware, where sellers also benefit from 0% state sales tax on inbound inventory.
Your Questions, Answered
Is Amazon FBA prep mandatory?
Yes. Every unit shipped into Amazon's FBA network must meet Amazon's packaging, labeling, and prep requirements before it arrives at the fulfillment center. Since Amazon stopped providing its own prep service in January 2026, sellers are fully responsible for compliance.
What happens if I send non-compliant inventory to Amazon?
Amazon can refuse the shipment at the receiving dock, charge per-unit inbound defect fees, quarantine the inventory, or in some cases dispose of units at the seller's cost. Listings associated with non-compliant inventory may also be temporarily suppressed.
How much does FBA prep cost per unit?
DIY prep materials typically cost between $0.15 and $0.50 per unit, plus your labor time. Third-party prep centers generally charge between $0.75 and $3.00 per unit depending on the prep complexity, with additional fees for receiving, storage, and outbound shipping. These are general industry ranges and vary by provider and product type.
Can I still prep FBA inventory myself?
Yes. There is no requirement to use a third-party prep center. Many sellers handle prep in-house successfully, especially at lower volumes with simple product types. The requirements are the same whether you prep yourself or outsource: units must arrive at Amazon fully compliant.
What is the difference between FNSKU and manufacturer barcode labeling?
An FNSKU is a seller-specific barcode generated by Amazon that tracks your inventory separately inside the fulfillment network. A manufacturer barcode (UPC, EAN, ISBN) identifies the product generically. Since March 2026, FNSKU labeling is mandatory for resellers not enrolled in Brand Registry. Brand owners with eligible manufacturer barcodes may still use them under Amazon's current policies.
How long does FBA prep take at a prep center?
Most prep centers complete standard prep within two to five business days of receiving inventory, depending on volume and complexity. Rush timelines are often available for time-sensitive shipments, typically at a premium.
Do all products require poly bagging for FBA?
No. Poly bagging is required for specific product types, including apparel, soft goods, products with loose parts, and items that could be damaged by dust or moisture. Products in manufacturer-sealed rigid packaging that would survive warehouse handling often do not need additional bagging. Check your product's specific requirements in the Send to Amazon workflow in Seller Central.
What are Amazon's inbound defect fees for non-compliant prep?
Amazon charges per-unit fees for various inbound defects, including missing or unscannable barcodes, missing prep (such as a required poly bag or suffocation warning), and box content information errors. The specific fee amounts are published in Amazon Seller Central and are subject to change. Since Amazon stopped correcting prep errors in January 2026, these fees apply to every non-compliant unit rather than being absorbed by Amazon's former correction service.