Packaging for Amazon FBA: FNSKU, Poly Bag and Prep Requirements

Amazon FBA (Fulfilled by Amazon) has specific packaging requirements that differ from standard retail or e-commerce packaging. Non-compliant products sent to FBA fulfilment centres are rejected, incur repackaging fees, or are disposed of at the seller's expense. This guide covers the key requirements that affect custom packaging design and labelling decisions.

FNSKU Labelling Requirements

Every FBA unit must have a scannable barcode that Amazon uses to track inventory. Options:

• Manufacturer barcode (UPC/EAN/ISBN): Amazon can co-mingle inventory with other sellers; not recommended for branded sellers
• FNSKU (Fulfillment Network SKU): Amazon-specific barcode; prevents commingling; required for new FBA sellers or any product enrolled in Label Required setting

FNSKU label specifications: minimum size 1×2 inches (25×50mm); black-on-white label; human-readable title and condition below the barcode; scannable from minimum distance of 4 inches. FNSKU labels must cover or replace any other barcodes to avoid scan confusion.

Poly Bag Requirements

Products sold as a unit in a poly bag must meet Amazon's poly bag rules:

• Poly bag must be 1.5 mil (38 microns) minimum thickness
• Bags with an opening of 5 inches (127mm) or larger must have a suffocation warning label
• Suffocation warning font size: minimum 10pt for bags under 60cm open circumference; 12pt for larger bags
• Warning text must be prominent and visible; Amazon-specified wording required
• Poly bag must be sealed (heat-sealed or tape-sealed) — not a loose cover

Set / Bundle Packaging Requirements

A "set" is multiple units packed and sold together as one SKU. Set packaging must be marked "Sold as Set" or "Do Not Separate" prominently on the packaging — either printed on the packaging or on a label that cannot be easily removed. Each component must also carry the set's FNSKU, not individual item barcodes.

Loose Product and Over-Boxing

Any product that might leak, spill or come apart during fulfilment handling must be completely enclosed in a sealed package. Liquids, creams and gels must be double-bagged or in sealed rigid packaging. Products with sharp edges must be packaged to prevent injury to fulfilment centre workers. If your product's retail packaging does not meet these requirements, an outer box or poly bag is required.

Packaging for SIOC (Ships in Own Container)

Amazon's SIOC program allows products to ship without an additional Amazon-branded outer box, reducing packaging waste and cost. To qualify, your retail packaging must pass ISTA 6 Amazon testing at a certified lab. Corrugated mailer boxes with sufficient edge crush test (ECT) rating typically qualify. SIOC-certified products earn the "Frustration-Free Packaging" badge, which can improve conversion.

Custom Packaging Design Checklist for FBA

• Barcode type confirmed (FNSKU or manufacturer code)
• Label placement area reserved on packaging design
• Poly bag requirements met if applicable (thickness, suffocation warning)
• Set labelling included if multiple components
• No protruding parts, sharp edges or loose components
• SIOC testing considered for corrugated mailer boxes
• Dimensions and weight comply with FBA size tiers to optimise storage fees