You filed your EU trademark with EUIPO. A few months later you get a publication notice. Most people file that away and move on. That is the moment the clock starts.
From the date your trademark is published in the EU Trade Marks Bulletin, any third party has 90 days to file a formal opposition. If they do, the registration process stops until the dispute is resolved. If nobody opposes, the trademark registers and you are done.
Anyone who owns an earlier trademark that they believe conflicts with yours. That includes registered EU trademarks, national trademarks in any EU member state, and in some cases unregistered marks with a reputation. They do not need to contact you first. They file with EUIPO directly.
EUIPO looks at three things: how similar the marks are visually and phonetically, how similar the goods and services are, and whether there is a likelihood of confusion in the market. A filing in a completely different industry is unlikely to succeed. A filing in the same class with a similar-sounding name is a real risk.
By the time an opposition is filed, you may have already invested months of marketing under that name. Changing course at that point is expensive. The 90-day window is your early warning system, not a formality.
The problem is that EUIPO does not send you a personal alert when someone files something similar. You have to actively check. Most small brand owners do not, because it requires knowing the bulletin exists and checking it manually.
Watch the EUIPO bulletin for new filings that are visually or phonetically similar to your mark, in the same or related Nice classes. If you spot one, you have options: file your own opposition, reach out to the applicant directly, or take no action if the conflict seems minor.
The important thing is that you know about it within the window. An opposition filed on day 91 is rejected automatically.
Sentin watches EUIPO daily and emails you if someone files a similar trademark. Free for one trademark, no credit card needed.
Start watching for free →If you want to read the official EUIPO guidance on oppositions, it is available on the EUIPO website under "Opposition procedure".
Related: Someone filed a similar trademark — what do you do?