How long do you have to oppose a US trademark?

How do you extend the US opposition deadline?

Through the TTAB’s ESTTA system, before the 30 days run out. A first 30-day extension is granted on request; further extensions can take the total to 90 days for good cause, and to 180 days with the applicant’s consent. The request must be filed inside the current window — an extension asked for on day 31 extends nothing.

Publication. Not filing, and not registration.

The application is examined first, then published. The clock starts at publication. Counting from the filing date makes you early, which is harmless. Counting from registration makes you late, which is not.

Not every office works this way.

The US opens the window at publication of the application, as most offices do. But Switzerland, Germany, Japan and Sweden register the mark first and run opposition from publication of the registration.

Applying one office’s rule to another does not shift a deadline by a few days. It invents one that never existed, and the real one may already have closed.

It is not over, but the route changed.

Once opposition lapses you are into cancellation or invalidity: a different action, different evidence, more cost, lower odds. Worth knowing early: a holder whose own book is largely lapsed or withdrawn is more vulnerable to a non-use challenge than the register first suggests.