FBA prep in the UK: Amazon's packaging and labelling rules, and what prep really costs

Prep is the least glamorous part of Amazon FBA and one of the easiest places to lose money without noticing. A missing label or a loose bag does not show up as a line in your P&L. It shows up as a shipment that takes days longer to go live, a small fee on every unit, and a product that runs out of stock while it sits in a receiving queue. This guide covers Amazon UK’s rules as they stand on 1 October 2026, and the cost of each way of meeting them. When the stock is ready, our guide to sending it with Send to Amazon takes over.

What changed in 2026

Both changes are on Amazon’s UK help pages: the end of the prep and label services on the FBA Prep Service and FBA label service pages¹², and the barcode change on the barcode FAQ⁵. Some other UK help pages still describe the old services, including the option to choose “By Amazon” as the prep owner³. Plan as if Amazon will not prep anything, because that is what its own notice says.

The barcode change is part of the end of commingling: customers who buy from you now receive units from your own stock⁵. For a brand owner that is good news twice over. You can skip stickers on eligible products, and nobody else’s stock is shipped against your listing.

Labelling: FNSKU or manufacturer barcode

Every unit needs a barcode Amazon can scan. There are two kinds: the manufacturer barcode (UPC, EAN, JAN or ISBN) and the Amazon barcode, an FNSKU label that starts with X⁸.

You can use the manufacturer barcode only if all of these are true⁶:

1. The product is new.
2. It has a single, scannable UPC, EAN or ISBN that matches a single ASIN.
3. It belongs to a brand in Amazon Brand Registry where you are the brand representative, and the product itself is registered to your brand. Enrolling the brand does not connect its products automatically.

Products with a product ID exemption cannot go stickerless, because only products with valid GTINs qualify⁵. Everyone else, including authorised resellers, must use Amazon barcodes⁵. Our Brand Registry guide covers enrolment.

If you apply FNSKU labels, Amazon’s specification is precise⁷:

• Black ink on white, non-reflective labels with removable adhesive, between 25.4 × 50.8 mm and 50.8 × 76.2 mm.
• Thermal or laser printers, at 300 dpi or more. Not inkjet. Labels must stay readable and scannable for 24 months.
• Laser label sheets from 21 to 44 labels per A4 page are supported; print at 100% scale.
• Put the label on a flat face, not a curve or corner, at least 6 mm from the edge, and on the outside of any bag or wrap.
• Cover every other visible barcode, except serial number barcodes and Transparency codes, and never cover warnings, safety information or the food information a label must show, such as ingredients, allergens and best-before date.

Each FNSKU must identify one product in one condition, so each size, colour and condition needs its own⁴.

If a unit that needs an Amazon barcode arrives without one, Amazon marks it defective, applies a sticker and records it on your Inbound Performance Dashboard⁶. For resellers there is a further cost: units without proper Amazon barcodes are not eligible for reimbursement if they are lost or damaged⁵.

Packaging requirements every unit must meet

Amazon UK’s general packaging rules⁴:

• Boxed units must be six-sided, with openings or lids that will not open on their own, and must not collapse under medium pressure. If the box has perforations or openings, the product must survive a 125 cm drop test (one drop on each side and one on a corner), or go in a poly bag with a suffocation warning.
• Sets and bundles need a label such as “Sold as set” or “This is a set. Do not separate”, and the barcodes of the individual items must face inward or be covered.
• No marketing materials: pre-priced labels, price tags, pamphlets and other non-Amazon labels are not accepted.
• Outer barcodes on shipping cartons must be covered or crossed out so the wrong code is not scanned at receiving.

Poly bags and suffocation warnings

Poly bags must be transparent, completely sealed and fit the product, extending no more than 7.5 cm beyond it, and the barcode must scan through the bag or be labelled on the outside⁴. Amazon specifies a thickness of at least 1.5 mil⁴. Its page gives the metric equivalent as 0.0254 mm, which is actually 1 mil, so we buy bags of 1.5 mil (about 0.038 mm) or thicker and meet both readings.

Every polythene bag with an opening of more than 12 cm must carry a suffocation warning, such as “Warning: To avoid danger of suffocation, keep this plastic bag away from babies and children.“⁴ Amazon’s UK page does not set a font size. Our practice is to buy bags with the warning printed on, rather than stickers that can fall off in transit. Highly scented products, such as candles, must be sealed or bagged so the scent does not transfer⁴.

Product types that need extra prep

Amazon lists the product types where prep may be required³, and its prep service list shows the treatment each one used to get¹. That treatment is now yours to provide.

Expiry-dated products

Amazon’s definition is wider than most brands expect. Anything with a shelf life, or that loses effectiveness over time, counts, even without a printed date: food and supplements, cosmetics and toiletries, cleaning products, and any product with a period-after-opening symbol⁹.

• Date format: DD-MM-YYYY or MM-YYYY, and MM-YYYY is read as the first day of that month⁹. If your packaging uses another format, Amazon’s two pages disagree: the packaging page says to cover the original with a correctly formatted sticker⁴, while the expiry page says not to conceal the original date⁹. Until Amazon reconciles them, check with Seller Support for your product, and better still, have the factory print the date in the accepted format.
• Where: on each unit and on the outer box, which needs the date in 36-point type or larger⁴. Case packs, multipacks and display boxes need it on the outer packaging and every item inside⁹.
• Shelf life on arrival: enough time to consume the product in full, plus 90 days. A tub of 240 daily servings needs 330 days left when it is checked in⁹.
• One date per ASIN per box. Units of the same ASIN with different dates go in separate boxes⁹.
• Expired on arrival means disposal, and that stock cannot be returned to you⁹.

Amazon’s guideline minimums give a sense of scale: 90 days for crisps and snacks, 180 for pet food and baby formula, 270 for drinks, 540 for sweets and canned food, 730 for supplements and 900 for cleaning, personal care and beauty products⁹. Check these against your factory’s production schedule before you book freight, not after.

Case-packed products

Case packs speed up receiving, because Amazon scans one unit and stores the whole box. The rules are strict⁴:

• Every unit in the box has the same SKU and condition and was packed together by the manufacturer.
• Every box of that product holds the same quantity: a case of 24 is always 24.
• No more than 150 units per case.
• Barcodes on the outer case are removed or covered, so the case is not received as one unit. Every unit inside still needs its own barcode⁷.
• A master carton holding several case packs is not a case pack, and must be split.

What prep mistakes cost

The direct fee is small. In the UK, Amazon’s unplanned service fee table now lists one problem, a missing Amazon barcode, at £0.15 a unit at the Standard coaching level and £0.30 at Elevated or Critical. It is charged only when Amazon provides a photo of the problem, and you can dispute it within 30 days¹⁰.

The indirect costs are larger:

• Time. Unplanned prep can delay full receipt of a shipment by up to 48 hours more than planned prep¹. For a product close to running out, that is two days of lost sales and rank.
• Coaching. Amazon measures your problem rate over 120 days for each problem group. Stay above the acceptable rate for more than 21 days and you move to Elevated; 21 more and you reach Critical, at which point Amazon may stop you choosing who preps and labels the affected products and charge a per-unit fee instead¹¹.
• Refusal. Amazon can refuse, return or repackage non-compliant stock, dispose of it, or block future shipments to the fulfilment centre⁴⁷.

Amazon tracks bagging, bubble wrap, labelling, quantity, safety, expiry and restricted-item problems on your Inbound Performance report¹². We review it after every shipment; the first repeat of a problem is the cheapest one to fix.

Prep in-house or through a prep centre: the per-unit maths

There are three ways to meet the rules, and the cheapest is usually the one that happens earliest.

1. At the factory. Ask your manufacturer to print the barcode on the packaging, apply FNSKU labels, bag with printed warnings and pack to Amazon’s case-pack rules. For brand owners, a GS1 barcode on the pack plus Brand Registry can remove labelling altogether⁶.
2. In-house, in your own warehouse.
3. A prep centre, which receives your freight, preps it and books it into Amazon.

The following worked example uses the National Living Wage of £12.71 an hour¹³; every other figure is an illustration, so use your own quotes.

At 5,000 units a month, in-house prep costs £0.25 a unit plus £600 ÷ 5,000 = £0.12 of fixed cost, so £0.37 a unit. The prep centre costs £0.48. The factory costs £0.05.

The in-house figure depends on volume, because the fixed cost is spread over fewer units when you send less. The break-even is easy to work out:

Here that is £600 ÷ (£0.48 − £0.25) = 2,609 units a month. Below that, the prep centre is cheaper; above it, in-house wins, and the gap widens as volume grows.

Two things the sum leaves out. A prep centre that also holds your overflow stock can save you storage at Amazon and help you stay inside your capacity limits, which our inventory management playbook explains. And whoever does the prep, the error rate matters more than the unit price: one rejected shipment can cost more than a year of the difference between two quotes.

A prep checklist before you book the shipment

1. Confirm each SKU’s barcode route: stickerless (eligible brand owner) or FNSKU.
2. Check each SKU’s prep category in Send to Amazon, and set your own if Amazon has not assigned one.
3. Test-scan a sample of labels through the bag.
4. Check expiry dates, formats and remaining shelf life against Amazon’s minimums.
5. Check case-pack quantities are identical and outer barcodes are covered.
6. Photograph a packed sample of each SKU. If Amazon reports a problem, the photo is your evidence.

Then move on to creating the shipment, using our Send to Amazon guide. If you are still deciding whether FBA is right for a product at all, start with what Amazon FBA costs and when it pays, and use the FBA fees guide and FBA calculator to put prep into the full cost per unit.