A cooling-off right is not universal
In one group of countries distance contracts carry a statutory cooling-off right — typically two weeks, no reason required. In another there is no such right at all: returns are a matter of the trader's own policy and binding only if promised. In between sit systems that apply it to particular contracts only. Check this before ordering, not afterwards.
Cooling off and guarantees are two different things
A cooling-off right covers goods that are perfectly fine but that you no longer want: short deadline, no reason, return postage usually at your expense. A guarantee or conformity right covers goods that are defective: much longer periods, a right to repair, replacement or refund, and costs borne by the seller. Choosing the wrong route loses rights you actually had.
How you paid is your strongest lever
When a trader fails to deliver or refuses to refund, a chargeback through the card scheme is often faster and more effective than any legal claim. It runs on its own short deadlines set by the payment provider. Bank transfers carry no equivalent protection, which is the single best reason not to pay in advance to a trader you do not know.
Where the trader is established decides a lot
Buying outside your own legal area usually means different rules and much harder enforcement. Add customs duties and import taxes, which can change the price substantially, and return shipping that sometimes exceeds the value of the goods. Marketplaces are not automatically liable for the sellers trading on them, whatever the checkout page implies.
Try dispute resolution before court
Where alternative dispute resolution schemes exist, they are free or very cheap and much faster than litigation. They generally require you to have asked the trader to put things right in writing, with a deadline. That one dated email is the entry ticket to everything that follows.
The law country by country
The legal framework, the procedure, the time limits and the costs differ from one country to another. Each country below has a detailed page: governing texts, key facts, the actual procedure, costs, where to go and the traps to avoid.
Select a country to open its detailed page.