In the application process for trademark registration, there will be a period for opposition if the trademark office approves the trademark to let the public to oppose the registration of the trademark.
Once you notice an application for registration of a trademark that is similar to your trademark, you should consider filing an opposition to the registration of the trademark.
Likewise, your application for registering a trademark may be opposed by a third party.
The opposition process is one of the more difficult aspects of the application for trademark registration. We recommend hiring a trademark practitioner to oppose the registration of a trademark or respond to an opposition to the registration of your trademark.