Trademark infringement is determined when a person uses a registered trademark as their own or part of their trademark, to deceive the consumers or to gain an advantage. To win in court, you’ll need to be able to prove that a legally recognized mark is yours. Additionally, you must show that your rights to the trademark are “senior” to those of the infringer, you have priority, and the use of the infringer’s mark will likely lead to confusion among consumers regarding the source of any goods or services sold under the contested mark.