Why an unused EU trademark can be cancelled

Using a trademark is not a condition of registering or renewing it in the European Union. It becomes a condition of enforcing it. Five years after registration, anyone you attack can demand proof that you have used the mark, and if you cannot produce it, your registration can be cancelled for the goods you cannot evidence.

What happens after five years?

The mark becomes open to a proof of use request. That request can arrive in two ways:

During an opposition you have filed. The applicant you are opposing asks you to prove use. If you cannot, the opposition is rejected and their mark registers.
Through a cancellation action. A third party applies to revoke your registration for non-use.

Both are administrative procedures at EUIPO. Neither requires anyone to go to court.

What does "use" actually mean here?

Genuine use in the course of trade: the mark connected to the registered goods or services, in the relevant territory, during the relevant five-year period.

Token use created to defend the registration does not count. Nor does internal use, or preparation that never reached the market.

What is the worst case?

Losing the registration for everything you cannot evidence. The mark may survive for the goods you genuinely sell and disappear for the rest, which is usually the part of the specification that was filed speculatively.

The less dramatic outcome is more common and still expensive: your opposition fails, and a competitor registers an identical or similar mark that you can no longer stop.

What should you keep?

Evidence, from the day you start trading, organised by year and by country:

Dated invoices showing the mark and the goods
Catalogues, packaging, labels
Advertising, with spend and dates
Sales figures broken down by member state
Screenshots of the site and listings, dated

Assembling this five years later from nothing is where most proof of use cases are lost. It is the cheapest insurance in trademark practice, and almost nobody does it until they need it.