At Precision, we see a lot of stock — and we see the aftermath of prep done incorrectly elsewhere. Some mistakes are minor inconveniences. Others cost sellers real money. Here are the most common prep errors and how to avoid every one of them.
Wrong or Missing FNSKU Labels
This is the most frequent and most consequential prep mistake. Applying the wrong FNSKU means Amazon receives a product and assigns it to the wrong listing in your inventory. You might end up selling a customer something completely different from what they ordered, resulting in returns, negative feedback, and potential account health issues.
Always double-check that the FNSKU on the label matches the product. Print labels one product at a time rather than in bulk to reduce the chance of mix-ups. If you are prepping multiple products in one session, keep them physically separated.
Scannable Original Barcodes Left Uncovered
If you are using FNSKU labelling (which you should be), the product's original UPC or EAN barcode needs to be covered with an opaque label or have your FNSKU placed directly over it. If both barcodes are scannable, the product might be received against the wrong listing or commingled with other sellers' stock.
Missing Suffocation Warnings
Poly bags with openings larger than 127mm require a printed suffocation warning. Sending products in bags without this warning violates Amazon's policy and can result in receiving issues. Use pre-printed warning bags or apply suffocation warning stickers — it takes seconds and prevents problems.
Inadequate Protection for Fragile Items
Products that arrive at Amazon damaged are marked as unfulfillable. If fragile items are not bubble-wrapped or adequately protected, they may not survive warehouse handling. Remember that Amazon's fulfilment centres are high-volume operations — products are moved on conveyor belts, stacked, and handled quickly. If your product cannot survive being dropped from waist height, it needs more protection.
Incorrect Multi-Pack or Bundle Prep
Sets and bundles must be packaged together with a "Sold as Set" sticker and a single FNSKU for the bundle. Forgetting the sticker means Amazon staff might separate the items. Using individual FNSKUs instead of a bundle FNSKU creates inventory errors. And not packaging the items securely together means they can become separated in the warehouse.
Shipping Plan Errors
Sending the wrong quantity of products (more or fewer than declared in the shipping plan), mixing products from different shipping plans in the same box, or using incorrect box content information causes delays at receiving and can trigger account warnings for repeated offences.
Poor Box Packing
Overpacking boxes beyond the 23kg weight limit, underpacking boxes so products move around and get damaged, using damaged or weak cardboard, and not using adequate void fill all cause problems at receiving. Pack boxes firmly but not beyond weight limits, use appropriate void fill, and ensure box labels are placed correctly.
Expiry Date Issues
Sending dated products with insufficient remaining shelf life, covering expiry dates with labels, or sending products without visible dates when they are required are all common errors. Always check dates before prepping dated products, and ensure dates remain visible after labelling.
The Prevention Mindset
Every prep mistake has the same root cause — rushing. Taking an extra 30 seconds per unit to verify the label, check the barcode, and confirm the packaging prevents hours of dealing with the consequences. Whether you prep yourself or use a prep centre, accuracy is more important than speed.
At Precision, we have a quality check built into every step of our prep process. Every label is verified, every bag is checked for warnings, and every product is inspected before it goes into a shipping box. It is attention to detail that prevents costly mistakes.