EU–Mercosur Trade Deal: What it Means for Cross-Border Ecommerce Sellers in Europe
24 March 2026
Barcode confusion: UPC, EAN, ASIN, FNSKU – what’s what?
24 March 2026
OUR GOAL
To provide an A-to-Z e-commerce logistics solution that would complete Amazon fulfillment network in the European Union.
At the beginning, prepping FBA shipments usually feels… pretty manageable. You get your products, print a few labels, pack the boxes, send them out. Done. It’s all under control, and honestly — it even feels good knowing everything is handled your way.
Then things start picking up. More orders. More SKUs. More shipments to prepare. And suddenly, what used to be a quick task turns into a big chunk of your day. You’re printing labels, checking requirements, fixing packaging, double-checking everything… and still wondering if Amazon will accept the shipment without issues. If you’re selling in Europe, it gets even trickier. The requirements are stricter, the margin for error is smaller, and what worked fine in the US doesn’t always hold up in FBA EU. This is the point where a lot of sellers start asking themselves the same question: Should I keep doing this myself, or is it time to outsource FBA prep to a prep center?
In the previous article, we showed how running FBA pre in-house usually looks like, with its pros and cons. Now meanwhile we'll focus on when and why you should consider switching from DYI to outsourced FBA prep.
What changes when using a prep center (3PL) for preparing your FBA inventory?
At some point, preparing FBA shipments just stops being a small task you squeeze in between other things and starts taking over your day. One shipment turns into a few, then suddenly you’re dealing with multiple SKUs, different requirements, and constant prep work that keeps piling up. What used to take a couple of hours now drags on, and instead of focusing on growing your business, you’re stuck managing labels, boxes, and deadlines. That’s usually when the thought of a prep center starts to make a lot more sense — doing everything yourself just isn’t working anymore.
So what actually changes when you decide to go that route?
The inventory can go straight from your supplier to the prep center
The first major change is that instead of ordering the products to arrive at your own warehouse, you can simply give your supplier the prep center’s address and make it the default destination for your inventory, which can already free a good part of your warehouse staff time. Based on the detailed guidelines you gave the 3PL staff earlier, when a shipment arrives, the warehouse team will receive and inspect the shipment, and if something is amiss, they will contact you immediately about the issue, so you can decide how to react - so you don't have to worry that the warehouse team will do something behind your back.
If you will feel more comfortable ordering the shipment from the manufacturer to your own warehouse, doing the inspection yourself and only sending it to the 3PL company then, that's not a problem. But think about it this way: imagine you have a particularly hectic day at the warehouse. You did schedule a worker to receive the new shipment, inspect the delivery, add it into the WMS and then hand it over to the FBA prep team...but at the moment the shipment arrives, all your workers are in the middle of other tasks.
One worker did receive the shipment, but then the cartons can sit unopened for a day or two, waiting until someone will have time to inspect and add the new delivery into WMS. And then people responsible for FBA prep are busy with other tasks, so they can't take over the FBA prep tasks yet - another day or two passes. It was unavoidable - you simply didn't have enough hands on board. But still, that significantly delayed the shipment to Amazon FBA and how quickly you can sell the products there.
3PL companies have a far larger warehouse staff, so such situations rarely happen - they can usually receive the shipment, inspect it and then move it for FBA preparing right away. Meanwhile you can see how the FBA prep process progresses on the dedicated WMS dashboard - so you stay in control, while also having less work on your shoulders. And in particularly hectic periods, knowing that products meant for Amazon aren't sitting idle in the warehouse but are processed all according to your requirements will definitely make scheduling and planning your own staff's work much easier.
They open cartons and verify what actually arrived
Once the shipment arrives, the cartons are opened and checked against what you ordered. Someone goes through the contents SKU by SKU, counts the units, and compares them with your purchase order — so you know exactly what physically arrived, not just what was declared by the supplier. Okay, this might sound like a pretty basic operation, but how many times has it happened that you or your staff didn't actually have enough time to verify what arrived and is everything in good condition?
In a prep center, the work is split between roles, so receiving doesn’t compete with other tasks in the warehouse. Receiving and inspection follow a set sequence — once a shipment is booked in, it moves to inspection as the next step, handled by the team responsible for that part of the workflow. That means cartons don’t sit unopened because the same people are busy with picking orders or packing outbound shipments. So if you ordered 500 units and only 480 show up, the prep center will call you to tell about this. If part of the shipment arrived damaged or packed inconsistently, it gets flagged before anything moves forward. And because this step connects directly to prep, there’s no gap between “we received it” and “we actually know what’s inside.”
Labeling (FNSKU and carton labels)
Once the inventory is checked, the next step is labeling. Each unit needs to be matched with the correct FNSKU and labeled in a way that Amazon can scan without issues. In a prep center, this usually happens SKU by SKU: the team takes one product, pulls up the correct label, and applies it across all units in the same way — same placement, same orientation, no mixing between batches. Okay, this might not sound like something unusual either.
In a DIY setup, labeling rarely happens in a clean, one-SKU-at-a-time flow. More often, you’re working on multiple products at once. You print labels for a few SKUs, lay them out on a table, and start applying them across different cartons. Then something interrupts the process — another shipment arrives, someone asks for help, or you need to switch to a different task. When you come back, it’s easy to lose track of where you left off. You might have two similar products next to each other or partially labeled batches that look the same at a glance.
That’s where small mix-ups happen. A few units get the wrong FNSKU, some labels end up placed in different spots, or part of the batch gets skipped entirely because it was already “in progress.” You don’t always catch it during prep but when the shipment reaches Amazon, those inconsistencies show up immediately during check-in — and that’s when fixing them becomes much more time-consuming.
With a prep center, labeling is organized so that one SKU is handled from start to finish before moving on to the next. The team pulls a specific product, checks the SKU in the system, and prints only the labels needed for that batch. Those labels stay physically with that product — they’re not mixed with labels for other SKUs on the same table. A worker applies labels to all units in that batch in one go, usually following a defined placement rule (for example, always on the same side of the packaging, not covering key product information). Once that SKU is done, it’s moved out of the labeling area before the next one comes in.
Because of that, you don’t get situations where multiple SKUs are open at the same time and labels from different products end up next to each other. There’s no need to “remember where you left off,” and no risk that partially labeled batches get mixed or finished incorrectly later.
They adjust packaging based on specific product requirements
Once labeling is done, the next step is making sure each product is packed in a way that meets specific FBA requirements. Each SKU is checked against its requirements. For example, if a product needs a polybag, they choose the correct size, seal it properly, and add a suffocation warning label if it’s required. If a product is sold as a bundle, they secure all items together so they won’t separate during handling. They also look at how the product arrived from the supplier. If the original packaging is too weak, gets easily damaged, or doesn’t protect the product well enough, they reinforce it before moving forward. That might mean adding extra protection inside the carton or repacking units so they can handle Amazon’s sorting and transport process without issues.
In a DIY setup, this is often where things become inconsistent. You might handle one batch carefully, then rush through the next one because you’re short on time, or miss a requirement because you’re working across multiple SKUs at once - and only notice the error once the shipment is on the way to Amazon. Here, those adjustments follow a defined set of requirements for each product. You’re not deciding on the spot how something should be packed — the process is already set, and each unit is prepared the same way before it moves to the next stage.
What problems a prep center actually solves
On paper, FBA prep looks simple. You receive products, pack and label them according to Amazon's guidelines, and send them out. But if you’ve ever handled it yourself, you know the real problems don’t come from not knowing what to do. They usually show up when you’re working on multiple shipments at once — labels printed for one SKU end up next to another, part of a batch gets labeled now and finished later, or cartons get packed before everything is fully checked. Those small inconsistencies tend to show up later, when something doesn’t match during check-in at Amazon.
A prep center meanwhile has both enough people and a tried-and-tested process FBA prep process to run those tasks consistently, with every shipment. And that solves quite a few problems you might come across while doing the prep work yourself:
1. Labeling errors disappear
Most labeling mistakes happen simply because the DYI process can get messy fast, especially during hectic period. You’re working on a few SKUs at once, labels are printed earlier and reused later, something interrupts the flow — and suddenly a few units end up with the wrong FNSKU or labels placed differently across the batch. It’s easy to miss in the moment as everything looks labeled and ready to go, but once the shipment reaches Amazon, those inconsistencies are flagged almost immediately.
With a prep center, labeling is organized so that one SKU is fully completed before another one is even brought to the workstation. A worker takes a single product, checks it against the system, and prints only the labels needed for that specific batch. Those labels stay with that product — they’re not placed on a shared table with labels for other SKUs.
All units for that SKU are labeled in one go. Once they’re done, they’re moved out of the labeling area — usually to a separate zone or pallet — before the next SKU is started. There’s no overlap where two similar products sit next to each other waiting to be finished.
Because of that, you don’t get situations where someone comes back to a half-labeled batch and has to figure out what’s already been done. You also don’t get labels from different SKUs ending up next to each other or being picked up by mistake. Each batch is clearly separated from start to finish, so there’s no point in the process where things can quietly get mixed up.
2. Compliance with Amazon EU requirements
If you’re used to the US, it’s easy to assume the same approach will work in Europe. Unfortunately, that's not entirely true. While some of the rules do overlap between Amazon USA and Europe, there are also plenty of new rules that are connected to EU regulations - which are just as strict as Amazon's rules. EU requirements also tend to be less forgiving when it comes to details — for example, how labels are placed on the product, whether any original barcodes are properly covered, or whether packaging includes all required elements like suffocation warnings when polybags are used. These aren’t things that usually cause issues in every shipment, which is why they’re easy to overlook. But when they do come up, it’s often at the worst moment — when the shipment is already at Amazon and something doesn’t pass their checks.
EU-based prep centers deal with these requirements every day, and so they typically have a ready process for prepping products according to the EU's regulations. Before prep starts, each SKU is usually assigned a specific set of requirements in the system — for example, whether it needs a polybag, where the FNSKU should be placed, or whether any original barcodes need to be covered. When the team starts working on that product, they follow the instructions already attached to that SKU, and so everyone knows how a given product should be processed.
This type of knowledge will be especially valuable if you sell products that have especially strict regulations in the EU, such as cosmetics or children's toys.
3. Fewer shipment rejections
Another benefit of working with a prep center is fewer shipment rejections. Since Amazon demands that each shipment meet their requirements perfectly and doesn't accept any shipment that misses even a single requirement, many shipments are rejected by the system just because of a minor oversight or accidental mistake. For example, you create a shipment in Seller Central and assign specific quantities per SKU, but when you’re packing cartons later, the actual numbers don’t match exactly — a few extra units end up in one box, a few are missing in another. Or part of the shipment was labeled earlier and the rest later, and not everything was updated consistently.
It can also happen that you pack cartons first and only then realize Amazon split the shipment across multiple fulfillment centers, so now the contents don’t match the routing plan. At that point, you either repack everything or try to adjust it manually, which increases the risk of further errors.
A regular warehouse might not pay much attention to those issues when accepting a shipment. Amazon's systems, though, are made to be as fast, efficient, and precise as possible, so once the shipment reaches Amazon, even small mismatches between what you declared and what actually arrives can lead to delays, extra checks, or the shipment being flagged altogether.
When you handle prep yourself, these steps often get split across different moments in the day — or even different days. That’s where mismatches start. The quantities in the shipment plan don’t fully match what’s packed. Some cartons contain a mix of SKUs that weren’t supposed to go together. Or part of the inventory was labeled under one shipment, but ends up being sent under another.
With a prep center, those steps are connected in one sequence. The team doesn’t label products and leave them for later — they label a SKU, move it directly into packing, and assign it to a specific shipment while everything is still in front of them. The same people handling the products also match them to the shipment plan, so there’s no gap where things can get out of sync.
Because of that, what gets packed is exactly what gets declared — and what gets declared is exactly what arrives at Amazon.
4. Faster turnaround
When you handle prep in-house, the delay between receiving the products from the manufacturer and sending it to FBA builds up across small gaps between steps. A shipment arrives in the morning, but your team is already busy, so cartons get received and moved aside for later. By the time someone actually opens them and checks what’s inside, it’s already the next day. Then labeling starts, but only part of the batch gets done before priorities shift again. The labeled units sit waiting to be packed. When someone finally comes back to them, they need to re-check what’s already been done, finish the rest, and only then start building cartons. Shipment creation in Seller Central happens at the end, based on what seems ready at that moment — not necessarily what was originally planned.
When you add it up, a process that could take a few hours ends up spread across several days — and your inventory only reaches Amazon once everything is finally stitched together.
With a prep center, these steps happen one after another, without being split across different days or competing with other warehouse tasks.
Once a shipment is received and booked into the system, it’s passed to inspection — not “later,” but as the next step handled by a different part of the team. As soon as that check is done, the same units move to labeling, and from there straight into packing and shipment preparation. There’s no point where cartons are set aside because the same people need to switch to another task. Receiving, inspection, labeling, and packing are handled by different roles, so the work keeps moving even if one part of the warehouse is busy.
In practice, that means inventory that arrives today can already be labeled, packed, and assigned to a shipment within the same working cycle — instead of being spread across several days. And the sooner that shipment leaves the warehouse, the sooner those products become available for sale on Amazon.
5. Less operational chaos
FBA prep doesn’t just add “more work” — it adds coordination between a lot of small things that all have to line up.
You need a place to put incoming cartons, and that space has to stay organized as new deliveries keep arriving. At the same time, you’re managing labeling — making sure you have the right labels printed for each SKU, keeping them separated, and making sure they don’t get mixed across batches. Then there are packaging materials: polybags, tape, warning labels — all of which need to be available exactly when the team starts prep. On top of that, different people are handling different parts of the process. Someone receives the shipment, someone else checks it, someone labels products, someone packs cartons, and someone creates shipments in Seller Central. If any of those steps get out of sync — for example, labeling is done but shipment creation is delayed, or cartons are packed before the final quantities are confirmed — things stop matching up.
With a prep center, you’re no longer the one checking whether a shipment has been opened, whether labeling has started, or whether cartons are ready to be packed. You don’t have to walk over to the warehouse to see what’s already done and what’s still waiting. You’re also not the one chasing updates — asking if the team has printed the right labels, whether a batch is finished, or why a shipment hasn’t been created yet in Seller Central. Those steps are handled within the prep center’s workflow, without you having to coordinate them manually.
Instead, you get visibility and full control without having to manage the execution. You can check the status of your inventory, see which shipments are in progress, and step in only if something needs your decision - and at any time you want.
How to know when it’s time to switch
There usually isn’t one specific moment where you decide to switch to a prep center. It’s more like this: shipments are still going out, but every one of them takes more coordination than it used to. You’re checking what’s been labeled, what’s still waiting, whether cartons match what you created in Seller Central — just to make sure everything lines up before it leaves the warehouse. And as volume grows, the same process starts taking more time, more attention, and more double-checking than before. That’s usually when the question “How long can I keep running it like this?” appears.
Here are a few situations that tend to show up around that point:
- You know a shipment needs to be labeled and sent out, but there’s always something in the way. Orders need attention, a delivery just came in, or your team is already tied up with other tasks. So prep gets pushed to “later today”, then to tomorrow, and then to whenever there’s time - simply because you don't have enough free hands on board.
You have one batch already labeled, another one partially done, and a third one just arrived and is waiting to be checked. Some products are ready to go, some still need work, and some were already assigned to a shipment — but you’re not 100% sure if everything is packed exactly the way it should be. At that point, you start double-checking things more often, because you don’t fully trust that everything still lines up.
You’ve had at least one shipment that didn’t match what you planned, for example, the quantities in Seller Central didn’t match what actually got packed, or maybe cartons were assigned incorrectly. And once something like this happened, you started being more careful with every shipment after that and that slows everything down.
People who were supposed to focus on other areas (fulfillment, inventory, operations) are now tied up with labeling, packing, and fixing issues. And when volume increases, things will take even longer, because there are not enough people to handle all tasks related to FBA.
You notice that shipments reach Amazon later than they should because when the inventory arrives, waits to be checked, then waits to be labeled, then waits to be packed. By the time everything is ready, a few extra days have passed — and your products are still not available for sale.
If you just thought "That's exactly how it looks right now at my company" and such situations are now happening more and more often, it’s usually a sign that your current setup is starting to limit how fast and how consistently you can move inventory to Amazon. That’s where a prep center starts to make a real, practical difference.
Instead of trying to push more work through the same setup, you move prep into a system where each step is already separated and handled by different people. One team receives and checks incoming shipments, another handles labeling, and another prepares cartons and assigns them to shipments.
You’re not trying to keep everything aligned manually anymore — checking if what’s labeled matches what’s packed, and if what’s packed matches what you created in Seller Central. The process is set up so those steps happen together, while the products are still in front of the same team. In practice, that means shipments move forward without you having to constantly step in — and your inventory reaches Amazon faster because it’s not waiting in between stages.
Where FLEX. Logistics fits in
At FLEX Logistics, we usually step in when FBA prep starts taking more time and coordination than it should and e-commerce brands need a bit more help with making sure the shipment made for Amazon is labeled and packaged exactly as Amazon demands it.
Here's how our FBA prep process typically looks like:
- Once your inventory arrives at our warehouse, we take over the prep process from the very beginning. We receive the shipment, open cartons, check what actually arrived, and let you know right away if something doesn’t match — whether that’s missing units, damaged products, or anything else that needs your decision before moving forward.
- From there, we move into labeling and packaging, but in a way that keeps everything organized. We work one SKU at a time, keep batches separated, and follow the exact requirements for each product, so you don’t end up with mixed labels, inconsistent packaging, or shipments that need fixing later.
We also connect prep directly with shipment creation. Instead of labeling and packing products first and figuring out the shipment later, we start with the shipment plan in Seller Central. We see how Amazon splits the inventory across fulfillment centers, what quantities are expected, and how cartons should be structured — and we prepare everything based on that from the beginning.
And if something comes back from Amazon — returns or removal orders — we can handle that too, so you’re not dealing with a separate process on your end.
You’re still the one deciding what gets sent and when. We’re just the ones making sure it actually gets done, without delays, without guesswork, and without you having to manage every step in between
If you’re starting to feel like FBA prep is taking over more of your time than it should, it might be a good moment to look at a different setup. Book a call with our team at FLEX Logistics and we’ll go through your current process together. We’ll show you where things can be simplified and how to get your inventory to Amazon faster — without adding more work on your side.
So how much is doing FBA prep in-house costing you?
At the beginning, doing FBA prep in-house just makes sense. You know what’s happening with your inventory, you keep everything under one roof, and the volume is still low enough to handle without too much friction.
But then things change — not all at once, just gradually.
There’s more inventory coming in. More shipments to prepare. More small things to keep track of. And even if everything is still technically working, it starts taking more time and more attention than it used to. You spend more time checking if everything is ready than actually moving things forward. Shipments go out, but later than planned. And every batch requires a bit more coordination than the last one. That’s usually the moment when doing it yourself stops being the “simpler option” — even if it still feels like the cheaper one.
Working with a prep center isn’t really about outsourcing for the sake of it. It’s about moving prep into a setup where things don’t depend on when you have time, who’s available, or whether everything lines up at the end. So if you’re starting to feel like prep is taking more effort than it should, it might be worth asking yourself:
Are you still choosing this setup — or just working around it?
