Willful infringement may exist when a potential infringer has actual notice of another's patent rights. If such notice exists, the potential infringer has an affirmative duty to determine if he is in fact infringing. "Such an affirmative duty includes . . . the duty to seek and obtain competent legal advice from counsel before the initiation of any possible infringing activity." The infringer may be liable for willful infringement if he does not act to determine if his action constitute infringement.
Willful infringement is only relevant in determining enhanced liability in an infringement case. For example, patent infringement is a strict liability issue. As such willfulness is not necessary to prove infringement, however; if one can prove willful infringement, then one may be entitled to enhanced/punitive damages as well.