First choose the business and responsibility model, then build the marketplace

The biggest mistake of a small marketplace is starting with a catalog, cart, and payments without determining who actually sells, accepts money, packs, imports, and handles complaints. These decisions change almost every subsequent obligation.

Base model recommended for small and medium-sized operators#

In a safe starting model:

each product has a clearly indicated seller;
the buyer enters into a sales agreement directly with the seller;
the operator provides an intermediation service and does not take title to the goods;
a licensed payment provider distributes funds and conducts the KYC required for payments;
the seller is responsible for product compliance, shipping, withdrawal, complaint, and sales documentation;
the operator is responsible for the interface, information, verification required by regulations, evidence, moderation, and case referral;
the operator does not import, repackage, or apply its own brand until a separate compliance process is launched.

Actions that change the operator from an "intermediary" to an entity with greater responsibility#

If the operator…	The risk arises that…	What to do before launching
sells its own goods	becomes the seller and distributor, and sometimes the manufacturer or importer	Separate own offers from others, assign consumer, product, VAT, and EPR responsibility.
offers goods under its own brand	becomes the manufacturer, even if someone else physically produces it	Implement the full manufacturer process: risk analysis, documentation, batch identification, warnings, recalls, and product category.
imports goods from outside the EU	becomes the importer or participates in import	Verify the manufacturer, the responsible person in the EU, documentation, labeling, VAT/customs, EPR, and traceability.
stores and packs orders	may be responsible for packaging, and the scope of its influence on the product increases	Establish EPR duties for materials added during fulfillment, control of batches, returns, and recalls; include the division of roles in the agreement.
collects money itself and later pays the seller	may provide a regulated payment service	Suspend this model pending written analysis. Use a licensed PSP with marketplace services as standard.
sets the final price, sales conditions, and communication as the owner of the goods	may be considered the de facto seller in relation to the consumer	Unify communication with agreements or consciously assume the role of seller and all its obligations.

Decisions that must exist in a single “model document”#

Before inviting the first seller, the management approves a short document describing:

Who is a party to the sales agreement and where the buyer sees this information.
Who issues the receipt or invoice.
Who sets the price, promotion, delivery cost, and deadline.
Who accepts withdrawal, complaints, and refund requests.
Who packs and ships, and who accounts for packaging.
Who imports, if the product comes from outside the EU.
Who stores product documentation and handles recalls.
How the PSP accepts funds, verifies the seller, makes distributions, and handles chargebacks.
Who is the data controller in each process.
Which categories, seller countries, and delivery destinations are allowed at the start.

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