What is FBA prep? Everything Amazon sellers need to know

If you have ever searched for what is FBA prep and ended up more confused than when you started, well, you are not alone.

Amazon makes it sound simple. Get your products ready, send them in, and start selling. But what Amazon does not tell you upfront is that getting your products “ready” suggests meeting a very specific set of requirements.

After months of research, you finally found a winning product, placed a bulk order, and sent it straight to Amazon. You’re already running the numbers in your head when the email arrives that the shipment was rejected.

Or worse, Amazon accepted it, shoved it into stranded inventory, and is now charging you storage fees on stock you can’t even sell.

This is what happens when FBA prep goes wrong. Most sellers learn this the hard way. This guide exists so you don’t have to. Let’s break down exactly what is Amazon FBA prep service, where sellers trip up, and how to make sure your inventory lands on Amazon’s shelves, not back on a truck to your garage.

Quick Guide:

• What is FBA prep?
• What are the FBA prep requirements you should make a note of
• What are the three ways to handle FBA prep?
• What DIY sellers consistently underestimate
• Which Option Is Right for You
• Pros and Cons of FBA Prep
• 8 Common FBA Prep Mistakes That Cost Sellers Money
• Final thoughts

What is FBA prep?

FBA prep is everything that needs to happen to your products before Amazon accepts them into its fulfillment center.

When you sell through Amazon FBA, you’re not shipping orders yourself. You send your inventory to Amazon’s fulfillment centers, and Amazon handles storage, packing, and shipping to the customer.

That’s the deal. But what happens before sending your products to the FBA center? Let’s figure it out.

What are the FBA prep requirements you should make a note of

Here is the list of FBA prep requirements you need to know.

Requirement 1: FNSKU Labeling

Every unit needs a scannable barcode generated specifically for your product and seller account by Amazon. This is the FNSKU, and it’s not interchangeable with your UPC or manufacturer barcode.

The rule is simple: one scannable barcode, on a flat surface, readable without repositioning the unit. Where sellers go wrong:

• Sending units with the manufacturer barcode still visible alongside the FNSKU. Amazon’s scanner picks up two codes and flags the unit immediately.
• When printing labels below 300 DPI, they scan inconsistently, causing receiving delays.
• Placing labels on curved surfaces, seams, or edges where the scanner can’t get a clean read.

Generate your FNSKU in, print on a 1″x2″ or 2″x3″ label, and cover every other barcode on the unit. That’s the standard.

Requirement 2: Poly Bagging

Required for soft goods, loose parts, plush items, and anything that could spill, scatter, or collect dust in transit. Amazon’s specs are specific:

• Transparent bags only
• Minimum 1.5 mil thickness
• Heat-sealed, not tape, not folded over
• If the opening is 5 inches or wider, a suffocation warning must be printed directly on the bag, not on a sticker, on the bag itself
• The FNSKU barcode must be scannable through the bag without opening it

Requirement 3: Bubble Wrap and Dunnage

If your product is fragile, it needs protection, but Amazon is specific about what kind. Allowed inside cartons: bubble wrap, full sheets of paper, inflatable air pillows, and foam padding.

Prohibited: packing peanuts, crinkle wrap, shredded paper, and foam strips. They escape from boxes and jam fulfillment center equipment. Amazon won’t just reject the shipment; they’ll note the violation against your account.

Requirement 4: Bundling and Kitting

Selling two or more items as a single ASIN? Every bundle must be packaged and labeled as a single unit. The requirements:

• Outer packaging must be clearly labeled “Sold as Set Do Not Separate.”
• Individual barcodes on items inside the bundle must not be visible or scannable through the outer packaging cover, or black them out
• The bundle FNSKU goes on the outside, and that’s the only barcode Amazon should be able to scan

Requirement 5: Custom Packaging

For fragile products, beauty, skincare, glass, and supplements in bottles, standard bubble wrap often isn’t enough. Amazon’s receiving process isn’t gentle. Units get conveyor-belted, stacked, and sorted at speed.

Requirement 6: Expiration Date Labeling

Applies to: food, supplements, vitamins, beverages, cosmetics, baby products, anything with a shelf life.

Requirement 7: Carton Labeling and Forwarding

Requirement 8: Palletization

Requirement 9: Pick and Pack

Requirement 10: Product Inspection

What are the three ways to handle FBA prep?

1. Do It Yourself

This will make sense when you, as a seller, are testing a product, working with low volumes, or just starting out.

Option 2: Amazon’s Built-In Prep Service

Sellers note that this service is no longer available.

Option 3: Use a Third-Party FBA Prep Center

A prep center receives your inventory from your supplier, inspects it, preps it to Amazon’s spec, and ships it in. You never touch the product.

Which Option Is Right for You

Pros and Cons of FBA Prep

The Pros

1. It keeps your inventory moving.
2. It protects your account health.
3. It acts as a quality control layer.
4. It gives you inventory flexibility.
5. It makes you a better operator.

The Cons

1. It adds cost at every stage.
2. It adds time to your inbound timeline.
3. Mistakes still land on you.
4. Amazon’s requirements change without much warning.
5. It’s one more thing that can break at scale.

8 Common FBA Prep Mistakes That Cost Sellers Money

Mistake 1: Sending units with manufacturer barcodes when FNSKU is required

Mistake 2: Polybags that are the right type but the wrong size

Mistake 3: Bundles where individual item barcodes are visible through packaging

Mistake 4: Expiration dates in the wrong format

Mistake 5: Shipping boxes that exceed Amazon’s limits

Mistake 6: Not removing price stickers from retail arbitrage products

Mistake 7: Not accounting for packaged dimensions in size tier classification

Mistake 8: Ignoring Amazon’s shelf-life minimums

Final thoughts

If you’ve been trying to understand what FBA prep is and why it matters so much, here’s the simplest way to think about it: it’s the difference between inventory that sells and inventory that sits in limbo, costing you money.

The FBA prep process isn’t the exciting part of selling on Amazon. No one gets into e-commerce because they love labeling requirements and polybag specs. But it’s the part that determines whether everything else you’ve built, right from the sourcing, the listing, and the PPC, actually pays off.