What should I do if someone else has already applied for or registered the trademark I want?

If you find out that another company has already applied for or registered a trademark, and they offer similar products or services as you, they have the rights to the trademark. You'll likely need to choose a different trademark to register.

In countries with 'common law' systems (like the U.S.), if they used the trademark before you filed yours, they might have legal rights to it based on how extensively they've used it.

If the other company has only used their trademark for a short time or in a small area, you might be able to apply again with the Trademark Office. However, be aware that your application is very likely to be rejected.