Amazon FBA FNSKU labels — the complete guide

What is an FNSKU?

FNSKU (Fulfilment Network SKU) is Amazon's internal ID for a specific product from a specific seller — it looks like X001AB2CDE. Every FBA inbound unit needs one stuck on the outside, and it must scan clean.

Approved FNSKU sizes

• 30-up sheet — 1 × 2 5/8 inches per label (Avery 5160 equivalent). Most common.
• 21-up sheet — 2.5 × 3 cm European (Avery L7160).
• Thermal roll — 2 × 3 inches or 1.5 × 2.5 inches. Faster if you have a Zebra.

Amazon rejects anything smaller than 1 × 2 inches. Do not shrink to save labels — a rejected shipment costs you far more than a roll.

Where to download FNSKU PDFs

1. Seller Central → Inventory → Manage FBA Inventory.
2. Select the SKU → Print item labels.
3. Choose label size and quantity. Download PDF.

Cropping the sheet

Amazon's PDF is a full 30-up sheet. If you have a thermal printer, drop the file into the FNSKU generator or the Amazon cropper — both will convert a 30-up A4 sheet into a thermal-roll-friendly single-column PDF you can print one label at a time.

The three rules for a scannable FNSKU

1. Vector source only. Never rasterize; barcode edges must stay sharp.
2. Print at 100% scale. No "fit to page" — the barcode width must stay exactly 1× or 1.5×.
3. Contrast matters. Cheap thermal rolls fade under UV and heat. Use archival-grade rolls if inbound stays in a warehouse for weeks.

Common Amazon FNSKU rejections

• "Label is unscannable" — usually a JPEG-to-PDF conversion. Re-download vector PDF.
• "Wrong FNSKU" — you reprinted an old label after Amazon reassigned the FNSKU.
• "Label covered by tape" — never tape over the barcode.