The launch question is not the account
Opening a Seller Central account is a quick administrative step; verification, tax interviews and brand enrolment can take considerably longer, and none of them validate the business behind the account. Building a channel that contributes margin takes a validated product, a chosen marketplace, a fulfillment model, stock cover and honest unit economics. The order matters: an account opened before the business is ready for the demand it buys produces expensive lessons.
This guide is the pre-launch validation we run with brands before spending a euro on marketplace advertising. It applies whether you sell from Portugal, Spain or anywhere else in Europe, and it is the same checklist our team uses when we operate a channel under an annual agreement.
Product and brand readiness
Amazon is a demand capture channel. It works when there is already search demand for the category and when the product answers a question a customer is already typing. Before launch, validate three things: people search for this kind of product, your offer has a defensible difference beyond price, and you can support the product after the sale with documentation, spare parts or support where the category demands it.
- Search demand exists and is stable, not only seasonal spikes.
- The product has a review-worthy reason to be chosen: function, design, bundle or service.
- Brand assets are ready: logo, images, A+ content inputs, brand story, Brand Registry eligibility where applicable.
- Compliance documents exist for regulated categories (cosmetics, toys, electronics, food).
Seller Central or Vendor Central
As Seller (3P), you control pricing, inventory and the customer experience, and you pay referral and fulfillment fees. As Vendor (1P), Amazon buys wholesale and controls retail pricing, promotions and the customer relationship, with its own order terms and margin expectations. Most brands launching in Europe start as Seller because it keeps control and because Vendor onboarding is selective and slower. Vendor enrolment is typically by invitation and its timing is outside your control; it can make sense for established brands with strong existing demand, but it changes the economics fundamentally: you sell at wholesale prices and lose direct control of the retail price.
Which marketplace first
Do not open five marketplaces at once. Start where demand, language readiness and logistics support overlap. For a brand based in Portugal, a common first step is the marketplace where the product already sells, in a language you can support, with stock reachable in reasonable transit time. Every additional marketplace multiplies listings, localisation, customer service, tax registrations and inventory planning.
- Choose the first marketplace by existing demand and delivery capability, not by catalogue size.
- Confirm you can answer customers in the marketplace's language.
- Keep the second marketplace as a planned step with a date and an owner, not an accident.
FBA or FBM: the real trade-off
FBA moves storage, picking, delivery and customer service for fulfillment to Amazon, and makes the product eligible for Prime. In exchange you pay fulfillment and storage fees, accept stricter packaging rules and lose some control of how stock is handled. FBM keeps control and can be cheaper for slow-moving or oversized items, but you carry the delivery promise and customer experience yourself, and conversion often suffers where customers expect Prime delivery.
A pragmatic model for many European brands is FBA for the fast-moving core and FBM for the long tail, reviewed quarterly against fee changes. The decision is economic, not ideological.
Stock cover and cash
A stockout during launch can interrupt sales momentum and slow the accumulation of reviews, and it wastes advertising spend on demand you cannot serve. As an example decision framework, many brands plan a minimum cover in weeks of expected sales and check that working capital can fund replenishment before the account generates cash; the right numbers depend on lead times, capital and category seasonality. For FBA, plan the inbound shipment lead time separately from supplier lead time.
Pricing, fees and unit economics
Model the unit before setting the price. Net proceeds per unit are what remains after referral commission, fulfillment or shipping cost, storage, advertising and returns. Amazon publishes its fee schedules, and they should be checked against your exact product dimensions and weight category, not estimated from memory. A product that looks profitable at a glance often stops being profitable once returns and advertising are honestly included.
For a deeper treatment of how contribution margin works per SKU and channel, read Contribution margin: the number that runs your business.
Returns and customer experience
Returns are a cost of the channel, not an exception. Estimate the return rate for your category from your own DTC data where possible, and build it into the unit economics. For FBA, confirm how returns are processed and whether products are resellable after return. For FBM, define who handles customer messages and how quickly, because response time affects account health metrics.
Advertising readiness
Before spending on advertising, the listing, the offer, the eligibility and the unit economics should be ready: finished images, title and bullet points, a competitive price, and stock to serve the demand the ads may create. A new listing often has too little organic traffic to measure a conversion rate, and waiting for one can be slow. Once the foundation is ready, a capped pilot campaign can generate genuine search-term and conversion learning that organic data alone will not produce, with a defined test budget and explicit evaluation criteria before any scaling. Amazon Ads do not fix a fragmented operation explains the diagnostic order we use.
A staged launch checklist
The sequence below is an example decision framework, adaptable by category, capital and risk appetite rather than a rigid gate. Each stage has an exit condition that tells you when the next investment is justified.
- Stage 1, validation: demand confirmed, unit economics modelled with real fees, stock cover defined. Exit condition: the unit contributes margin after returns and advertising at a realistic conversion rate.
- Stage 2, foundation: Seller Central account healthy, first marketplace set up, listings published, FBA/FBM model chosen, Brand Registry started where eligible. Exit condition: listings live, correct and findable by search terms.
- Stage 3, first demand: organic sales observed, detail page conversion measured, reviews accumulating, customer messages answered within SLA. Exit condition: the listing converts, account health is clean, and the conversion signal is measurable, whether from organic traffic or from a capped pilot.
- Stage 4, acceleration: sponsored campaigns launched against the known conversion rate, budget scaled only while contribution holds, stock cover monitored weekly. Exit condition: advertising spend growth that does not dilute contribution per unit.
- Stage 5, expansion: second marketplace, new SKUs or new fulfillment model added only after stage 4 is stable and documented. Exit condition: each addition reviewed as its own mini-launch.
Taxes and compliance: coordinate, do not assume
Where and whether you must register for VAT depends on several facts: where your inventory is stored, where the sales are made (the place of supply), which scheme applies to the transaction, and the status of your business. If you use FBA, Amazon may store your inventory in multiple countries, and storage location is one of the factors that can create registration and reporting obligations. The European Commission operates a One Stop Shop scheme that can consolidate cross-border VAT reporting for many sellers, but it does not remove the underlying obligations, and whether it applies to you depends on your facts. We cannot give you a blanket conclusion, so we coordinate with qualified tax advisers rather than guess.
This article is general information for operators, not personalized tax or legal counsel. Verify current rules and rates with the official sources linked below and with your own advisers before committing to a structure.
Direct answers
Should we launch on Amazon or improve DTC first?
If there is proven search demand in your category on Amazon and your DTC channel already converts, Amazon can capture demand you are not reaching. If the product itself is not validated, no channel fixes that. The honest test is whether customers search for the problem your product solves and whether the unit works economically after fees, returns and advertising.
How long should a launch take before judging it?
Reviews and organic ranking build over weeks, not days. Judge a launch on a defined horizon that suits your category and capital, against the conversion rate and contribution per unit modelled before launch, and treat the horizon as a planning example rather than a rule. Judging after a few weeks of advertising usually produces the wrong conclusion.
Official references
- Amazon (EU seller portal): start selling Official Amazon Europe seller page; checked October 2026.
- Amazon (EU seller portal): selling fees Official Amazon Europe fee page; check the schedule for your category and size tier. Checked October 2026.
- Amazon (EU seller portal): Fulfillment by Amazon Official Amazon Europe FBA page; checked October 2026.
- Amazon (EU seller portal): Fulfilment by merchant Official Amazon Europe page on the seller-managed fulfilment model; checked October 2026.
- European Commission: VAT One Stop Shop Official European Commission explanation of the One Stop Shop scheme; checked October 2026.
- Portuguese Tax Authority (Autoridade Tributária e Aduaneira) Official Portuguese tax authority portal; checked October 2026.
Fee structures, compliance rules and VAT schemes change. Always confirm current figures on the official sources above before making decisions.