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Every unit you send to Amazon needs a scannable label, either an FNSKU or an approved manufacturer barcode, plus a unique box ID label on each carton. Labels must sit on a flat surface, meet Amazon’s size and print specs, and never overlap a seam or corner. Before you print anything, check your ASIN’s barcode setting in Seller Central, generate FNSKUs where required, and print at 300 DPI on non-reflective adhesive paper.

TL;DR:

• Ensuring the correct barcode type is used for each product depends on the selling method, inventory setup, and whether the brand participates in Amazon’s Transparency program.
• Proper label placement on flat, smooth surfaces and covering any existing manufacturer barcodes reduces the risk of scan failures during receipt processing.
• Labels should be printed at 300 DPI on non-reflective adhesive paper, sized approximately 1 to 2 inches by 2 to 3 inches, and tested with a barcode scanner before shipping.
• Reusing or incorrectly applying box labels, or placing labels on curved or folded surfaces, can cause delays, rejections, and misidentification of inventory.
• Outsourcing labeling to a partner like Usiship helps maintain consistent quality, compliance, and reduces errors, especially when scaling to larger product volumes.

Table of Contents

• What Labels Does Amazon Require for FBA Products?
• What Are Amazon’s Label Size and Print Specifications?
• Where Should FBA Labels Go on Your Product?
• What Prep Rules Affect How You Label Different Products?
• How Do You Label FBA Boxes and Prepare Inbound Shipments?
• What Are the Most Common FBA Labeling Mistakes?
• How Can a Logistics Partner Handle FBA Labeling for You?
• Where to Verify Amazon’s Official Labeling Rules
• What the Research Actually Tells Sellers to Prioritize
• Let Usiship Handle FBA Labeling and Prep for You
• Sources

What Labels Does Amazon Require for FBA Products?

Amazon doesn’t use one barcode for everything. Which one your product needs depends on how you’re selling it, whether you commingle inventory, and whether your brand is enrolled in Transparency. Getting this wrong is one of the most common reasons new sellers get units flagged at receiving.

FNSKU (Fulfillment Network Stock Keeping Unit) is Amazon’s own barcode, unique to your seller account and listing. You need it whenever you’re not opted into “commingled” inventory, or whenever Amazon can’t reliably match your product to your listing using the manufacturer’s barcode alone. The FNSKU label carries the barcode itself, the FNSKU number in text, the product title, and the condition (new, used, and so on). Amazon’s own packaging and prep guidance spells out that exact content requirement.

Manufacturer barcodes (UPC, EAN, ISBN) work only if you’ve opted into Amazon’s “stickerless, commingled inventory” program for that ASIN. That setting lives on the product’s edit page in Seller Central, under the “Fulfillment” tab. If you haven’t explicitly opted in, Amazon defaults to expecting an FNSKU, so check this before you order labels for a new SKU.

Transparency barcodes apply to brand-registered sellers enrolled in Amazon’s Transparency program, which assigns a unique code to every single unit, not just every SKU. If your brand uses Transparency, that code replaces the FNSKU on the unit label and gets scanned at multiple points in the supply chain to fight counterfeiting. You apply it the same way you’d apply an FNSKU: printed clearly, on a flat surface, unobstructed.

Expiration date and lot labeling kicks in for anything perishable or regulated: supplements, food, cosmetics, and similar goods. Amazon requires the expiration date printed in a human-readable format directly on the unit (not just the case), and many categories also require a visible lot or batch number. If your product’s shelf life is under a year, Amazon may reject it outright regardless of labeling, so check category-specific rules before you commit inventory.

“Sold as set” labeling matters when you’re shipping multiple pieces that customers buy as a single unit, like a three-piece cookware set or a bundle of six candles. Each set needs one FNSKU on the outer packaging, and you should also mark the outer packaging clearly as “Sold as Set” so warehouse staff and returns processors don’t separate the pieces. Miss this step and Amazon may split your bundle into individual units during receiving, which usually creates a listing mismatch.

What Are Amazon’s Label Size and Print Specifications?

Amazon’s specs aren’t arbitrary. A label that’s too small, too glossy, or printed at low resolution will fail a scanner, and a failed scan at a fulfillment center means delays or outright refusal.

• Size: Amazon recommends labels roughly 1 to 2 inches tall and 2 to 3 inches wide. Stay inside that range and you avoid both unreadable tiny barcodes and oversized labels that won’t fit your packaging.
• Resolution: Print at a minimum of 300 DPI. Anything lower and the bars in your barcode start to blur together, which is exactly what causes mis-scans on the warehouse floor.
• Printer type: A laser printer is the standard recommendation because it produces crisp, dense black lines that hold up under handling. Inkjet can work in a pinch, but the ink tends to smear if a label gets damp or rubs against packaging.
• Material: Use non-reflective, adhesive-backed paper. Glossy label stock reflects light back at handheld scanners and causes read failures, which is a surprisingly common problem for sellers who buy generic label rolls without checking the finish.
• Ink color: Black ink only. Colored or low-contrast barcodes routinely fail to scan.

For file prep, export your label PDF at its actual print size and never let your printer “scale to fit” the page. Scaling distorts the width of the barcode’s bars just enough to break the scan, even though the label looks fine to the eye. If you’re printing in batches, use full label sheets rather than one-off single labels; it’s faster and it forces consistent sizing across a run.

Pro Tip: Print a test sheet of five labels and scan each one with a phone barcode app before you commit to a full batch. It takes two minutes and catches DPI or scaling problems before you’ve wasted three hundred labels.

Where Should FBA Labels Go on Your Product?

Placement causes more receiving headaches than almost anything else in the prep process, mostly because sellers assume “on the box somewhere” is good enough. It isn’t.

1. Put the label on a smooth, flat surface. Avoid corners, curved edges, seams, and anywhere the packaging bends, since a curved label distorts the barcode just enough to fail a scan.
2. If your product already has a manufacturer barcode visible on its packaging, cover it completely with your new label. Amazon’s guidance is explicit here: an exposed UPC or EAN next to your FNSKU creates a real risk that a scanner reads the wrong code and assigns your unit to the wrong listing.
3. For products in polybags, the label goes on the outside of the bag, never underneath it. If the bag’s opening measures more than 5 inches, it needs a printed suffocation warning in addition to the product label, a requirement detailed in Amazon’s bagging rules.
4. Shrink-wrapped items follow the same “cover the old barcode” rule, but you’ll often need to place the new label on a small flat panel you leave unwrapped, since shrink film itself can distort a scan even through clear plastic.
5. Irregular or oddly shaped items (think coiled cables or curved tools) usually need a small flat cardboard insert or backing card specifically so the label has a surface to sit on. Skipping this step is one of the more overlooked causes of receiving delays for oddly shaped inventory.

What Prep Rules Affect How You Label Different Products?

Labeling doesn’t happen in a vacuum. What you’re required to put on a unit often depends on how that unit gets packed, and Amazon updates these prep rules periodically based on damage and injury patterns it sees at scale.

• Bag versus bubble wrap comes down to fragility and choking risk. Soft goods and anything with sharp edges typically get bagged; anything breakable gets bubble wrap, and bubble-wrapped items still need the label accessible on the outside of the wrap, not buried inside it.
• Any poly bag with an opening larger than 5 inches needs a suffocation warning printed directly on the bag, worded to warn about the choking hazard to children. This applies regardless of what’s inside the bag, clothing, small parts, or accessories.
• Apparel and footwear often need size stickers visible through the packaging in addition to the FNSKU, since Amazon’s warehouse staff use that to verify against the listing during spot checks.
• Liquids and fragile items generally require additional cushioning and, in some categories, a “fragile” or “this side up” marking on the outer case, separate from the unit-level FNSKU.
• Amazon revises its prep requirements periodically based on damage and return data, so a rule that didn’t apply to your category last year might apply now. Check your specific ASIN’s prep guidance in Seller Central before every shipment, not just once when you first list the product.

How Do You Label FBA Boxes and Prepare Inbound Shipments?

Box labeling is a separate job from unit labeling, and mixing the two up causes more receiving exceptions than almost any other error.

• Generate a unique box ID label for every carton directly through the shipment workflow in Seller Central. Amazon assigns each box its own ID tied to that specific shipment plan.
• Never photocopy or reuse a box label from a previous shipment. Duplicate box IDs confuse Amazon’s receiving system and can cause your whole shipment to get flagged.
• Apply box labels to a flat side of the carton, away from any seams, tape lines, or existing shipping labels.
• For pallets or large multi-box shipments, follow Amazon’s pallet labeling requirements separately. This typically means labeling each individual box plus a pallet placard.
• Cover or remove any pre-existing external barcodes on cartons, including old shipping labels from your supplier, before your FBA box label goes on.

What Are the Most Common FBA Labeling Mistakes?

Most labeling problems come down to a short list of repeat offenders, and Amazon’s response to each one costs you time, money, or both.

1. Wrong barcode type applied. Using a manufacturer barcode on an ASIN that requires an FNSKU (or vice versa) causes a listing mismatch. Amazon may refuse the shipment or repackage it at your expense.
2. Low-quality prints. Blurry or scaled barcodes fail scans at receiving, which slows your entire shipment down while staff manually verify units.
3. Uncovered manufacturer barcodes. Leaving the original UPC visible next to your FNSKU risks a mis-scan that assigns inventory to someone else’s listing.
4. Reused or duplicate box labels. This confuses Amazon’s tracking system and can delay an entire shipment, not just the one mislabeled box.
5. Bad placement. Labels on curved surfaces, seams, or corners fail to scan and get bounced back for manual handling.

Amazon’s typical response ranges from a warehouse-level repackaging fee to outright refusal of the shipment, and either outcome eats into your margin and delays your inventory going live. The fix is a QC checklist you run before every shipment leaves your facility: confirm barcode type against Seller Central, check print quality against a sample scan, verify placement, confirm every manufacturer barcode is covered, and double-check no box label is reused from a prior shipment.

Pro Tip: Keep a printed copy of your last rejected shipment’s error notice pinned near your packing station. Recurring errors usually trace back to the same one or two steps in your process, and seeing the actual rejection reason in front of you catches repeat mistakes faster than any checklist.

How Can a Logistics Partner Handle FBA Labeling for You?

Outsourcing labeling and prep to a partner like Usiship removes the guesswork from this whole process. A dedicated fulfillment operation applies FNSKU and box ID labels at consistent 300 DPI print quality, handles bagging and suffocation-warning application on every applicable unit, and runs inbound QC before your shipment ever leaves the building.

• Label printing and application for FNSKU, Transparency, and box ID labels
• Bagging, bubble wrap, and suffocation-warning compliance handled per unit
• Denied-party screening to help prevent shipment holds before they start
• Dock and freight-classification support through resources like an NMFC checklist for larger inbound loads

For sellers shipping repeat batches, that QC layer catches the exact mistakes that cause receiving fees.

Where to Verify Amazon’s Official Labeling Rules

Amazon’s own packaging and prep guidance and Seller Central help pages are the source of truth for any labeling question. Avery’s practical labeling walkthrough and the suffocation warning reference are useful for execution details, but cross-check anything against Seller Central before you print.

What the Research Actually Tells Sellers to Prioritize

Most labeling advice online treats every rule as equally urgent, and that’s the wrong instinct. The size and print specs matter, but they’re the easy part; any competent printer setup solves them in an afternoon. What actually causes shipment delays is inconsistency across a growing catalog: one SKU set up correctly, the next one shipped with a leftover manufacturer barcode nobody covered.

The conventional advice treats FBA labeling as a one-time setup task. It isn’t. Amazon revises prep requirements based on damage and return patterns, which means a process that passed clean six months ago can start throwing errors today without you changing anything on your end. Sellers who build a repeatable QC checklist, checked against Seller Central before every shipment, catch these shifts before they cost a rejected pallet.

If you’re scaling past a handful of SKUs, the highest-value fix isn’t better labels. It’s removing the manual step where a person decides which barcode type goes where. That’s the point where errors creep in, and it’s the point where outsourcing to a partner with a standing QC process starts paying for itself.

— Akbar

Let Usiship Handle FBA Labeling and Prep for You

A logistics partner can handle label printing and application, relieving you from buying label stock, testing DPI settings, and building QC checklists, by applying necessary labels correctly.

That matters most if you’re scaling past a few SKUs a month, since the labeling mistakes that slip through usually happen when volume outpaces your in-house process. Usiship’s omnichannel fulfillment services cover label application, suffocation-warning compliance, and inbound QC as part of standard prep, backed by denied-party screening that helps keep shipments moving instead of sitting on hold. If your last few shipments got flagged for barcode or box-label issues, that’s the signal to stop DIY-ing prep. Get in touch with Usiship to talk through your next inbound shipment and see how prep and labeling would run through their network.

Sources

• FBA prep, packaging, and labeling: A beginners guide – Sell on Amazon
• Bag suffocation warning guidance – ComplianceGate
• How to label your products correctly for Amazon FBA – Avery

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• FBA Prep Services Guide