The 3PL onboarding process explained: a step-by-step checklist
Onboarding slips because of missing barcodes and unmeasured products, not because of the warehouse. Everything to have ready before your stock leaves the building.
Amazon FBA
Amazon has been closing its own prep and labelling service, and UK sellers were given 1 July 2026 as the date. Here is what FNSKU labelling actually requires in 2026, what a third-party FBA prep centre should cost, and how to pick one that will not get your shipments rejected.

Short answer: if you resell on Amazon UK, every unit you send to FBA needs an Amazon barcode (FNSKU) on it, and has done since 31 March 2026. Brands enrolled in Amazon Brand Registry are the exception. Amazon has been closing its own prep and labelling service, so the labelling falls to you or to a prep centre. Ours costs 55p per unit for receiving, inspection and the FNSKU label, with no minimum, and stock goes on to Amazon within 48 hours of arriving.
A note on spelling before we start: you will see this written as both FNSKU labelling and FNSKU labeling, and as both prep centre and prep center. British and American spellings, same service. We use the British spelling throughout, and Amazon’s own documentation uses the American one.
FNSKU stands for Fulfillment Network Stock Keeping Unit. It is a unique barcode that Amazon assigns to each of your products, and it is the thing that ties a physical unit in a fulfilment centre back to your listing rather than someone else's.
It prevents commingling. Without an FNSKU, your product can be mixed with other sellers' identical items. If their unit is counterfeit or poor quality and a customer receives it, the complaint lands on your listing.
It is mandatory for resellers. As of 31 March 2026, resellers in the UK are required to use Amazon barcodes (FNSKU) rather than manufacturer barcodes such as EAN or UPC. Brand owners enrolled in Amazon Brand Registry are the exception and can keep using their manufacturer barcodes, as GS1 UK sets out.
It keeps tracking accurate. Amazon's warehouses scan these barcodes from receipt through to shipment. A mislabelled item can mean lost stock or a rejected inbound shipment.
Amazon FBA compliance in 2026 UK terms comes down to three rules that are unglamorous and completely unforgiving:
Plan as if it does not. Amazon has been closing its own prep and labelling service one market at a time. It ended in the US on 1 January 2026 and in Canada on 1 July 2026, and both dates are in Amazon's own notices to developers. For the UK and the rest of Europe, the notice quoted by UK sellers and prep firms gives the same date, 1 July 2026, and says it covers stock arriving through Amazon Global Logistics and Amazon SEND as well.
One thing does not line up, and we would rather say so than paper over it. Amazon's rate card for Europe, effective 1 July 2026, still prints the old per-unit prices for that service: a label for 38p on an envelope, 78p on a parcel and 94p on an oversize item. So do not take any guide's word for it, ours included. Open a shipment in Seller Central and look at who is allowed to label the units. If Amazon is not on the list, the question is answered for your account.
Either way the sum is the same. Those Amazon prices were for sticking the label on and nothing else: nobody counted the delivery against your purchase order, checked the units for damage or built the cartons. That work was always yours.
If you are doing online arbitrage, wholesale or private label at small volume, handling FBA prep yourself is:
This is the gap a third-party FBA prep centre fills.
There are specialist 3PL and FBA prep centres across the UK that work specifically with small and medium sellers, rather than turning you away below a few thousand orders a month. Searching for an Amazon FBA prep near me, or an Amazon FBA prep center UK, is a reasonable starting point, but proximity matters far less than you would think: your stock arrives by courier and leaves by courier, so a prep centre two hundred miles away performs identically to one down the road.
Start with the one price list everybody can check. Amazon's Europe rate card dated 1 July 2026 lists its own label service at 38p for an envelope, 78p for a parcel and 94p for an oversize item, and that is for the label alone. Bagging is a further 53p to 86p and bubble wrap 60p to £1.31, depending on size.
A prep centre should come in under that for a parcel and do more for the money. Ours, from the FBA prep page:
| Service | 1 to 999 units | 1,000 to 2,999 | 3,000+ |
|---|---|---|---|
| Receive, inspect and FNSKU label | 55p | 45p | 40p |
| Polybag with suffocation label | +25p | +22p | +20p |
| Bubble wrap | +45p | +40p | +35p |
| Bundling and multipacks | from 50p | from 45p | from 40p |
Sending the finished cartons on to Amazon is charged at the carrier's cost plus £2.50 a carton for handling.
The mechanics are much the same wherever you go:
Two dates matter more than anything else on this page right now. Amazon's UK cut-off for stock to arrive in time for Black Friday week is 28 October 2026, according to its peak season post in Seller Central, and delivery slots get harder to book from here. Work back from that: a prep centre needs your stock in the building, counted and labelled before it can book the collection, so the real deadline for your supplier is days earlier.
The other is 1 October, when Amazon's storage price moved to its October to December rate. Not everything you own needs to sit there at that price. Our piece on Amazon FBA storage fees in the UK sets out what to send in and what to hold back.
Not as something to plan around. Amazon ended its own prep and labelling service in the US on 1 January 2026 and in Canada on 1 July 2026, and the notice quoted by UK sellers gives 1 July 2026 for its European stores, the UK included. Amazon's Europe rate card dated 1 July 2026 still prints the old label fees, so check whether Amazon is offered as the label owner in your own shipment before you rely on either answer. The work now sits with you or with a prep partner.
From 31 March 2026, resellers in the UK must use Amazon barcodes (FNSKU) rather than manufacturer barcodes such as EAN or UPC. Sellers enrolled in Amazon Brand Registry are exempt and can keep using their EAN or UPC. Beyond the rule itself, FNSKU is what stops your stock being commingled with other sellers' units.
Our published rate is 55p per unit for receiving, inspection and FNSKU labelling, falling to 45p from 1,000 units and 40p from 3,000. For comparison, Amazon's own Europe rate card dated 1 July 2026 lists its label service at 38p for an envelope, 78p for a parcel and 94p for an oversize item, for the label alone. When you compare prep centres, add any monthly membership and per-box fee to the unit rate. The full rate card is on our pricing page.
At many prep centres, yes. Ours has no minimum unit count and no minimum monthly spend, which is the specific reason small sellers end up here: the volume that gets you turned away elsewhere is the volume we were built for.
Almost never. Stock arrives by courier and leaves by courier, so a prep centre's postcode has no bearing on how fast your customers receive their orders. What matters is the cut-off time, the goods-in speed and the compliance record.
Yes, and it is worth insisting on. A centre that preps but leaves you to arrange FBA prep and shipping separately has handed the hardest part back to you. Look for one that creates the shipping plan or applies your box labels and dispatches to the fulfilment centre directly.
Finding a partner for Amazon FBA prep in the UK with FNSKU labelling does not have to be stressful. With Amazon stepping back from prep, third-party specialists have become essential for small sellers who want to stay compliant and grow without the whole thing running on their evenings.
Pick on three things: an accuracy figure in writing, pricing you can read before you commit, and a turnaround that holds when it gets busy. Everything else is detail.
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