The United States Copyright Act sets a relatively brief window of time for copyright owners to file infringement complaints, namely three years. But when does the clock start running? If you are a copyright owner who has recently discovered an infringement on your copyright, but the infringement happened more than three years ago and has not been repeated, what are your options?

The statute bars claims outside of three years after the claim accrued. See 17 U.S.C. § 507(b). But the statute does not clarify what it means for a claim to accrue. In general, statutes of limitations can start running from moment of the “injury” or from the moment the injured discovers the injury. Thus, courts generally use the “injury rule” or the “discovery rule,” depending on the established rules for different bodies of law. So in a copyright situation, the question is whether the infringement itself starts the clock, or if the clock is “tolled” until the copyright owner discovers the infringement.

The answer is very important; practically speaking, if a court uses the discovery rule when a plaintiff was in the dark about an infringement for five years, a suit will not be barred at the time of discovery. But if the court prefers the injury rule, there is nothing the plaintiff can do against a five-year-old infringement.

Unfortunately for both copyright owners and lawyers, the courts have yet to present a completely unified standard. While the US Supreme Court has not explicitly decided the matter, the US Circuit Courts of Appeal seem to be mostly embracing the discovery rule. Relevant to Michigan residents, the 6th Circuit has preferred the discovery rule over the course of several cases, for instance see Bridgeport Music, Inc. v. Diamond Time, Ltd., 371 F.3d 883 at 889 (6th Cir. 2004), or Frank Betz Associates, Inc. v. J.O. Clark Const., L.L.C., 3-08-0159, 2009 WL 47143 at 2 (M.D. Tenn. 2009).

Therefore, if you just discovered an infringement on your copyright that happened more than three years ago, it is likely that your claim will be allowed to go forward, but be sure to consult with an experienced intellectual property lawyer who is aware of the current trends within your jurisdiction. Above all, however, if you are a copyright owner, know that vigilance pays off. Be alert to copyright infringements. In the courts’ eyes, “should have known” is the same thing as knowing, and so even in a discovery rule jurisdiction, the clock starts running when the infringement is reasonably discoverable. In an injury rule jurisdiction, vigilance is even more important; the copyright owner must always be on guard.