Most patent practitioners engaged in Inter Partes Review (IPR) proceedings are familiar with the “one-year rule.” The one-year rule, codified in 35 U.S.C. § 315(b), bars a party from filing an IPR petition challenging the validity of a patent’s claims “more than 1 year after the date on which the petitioner . . . is served with a complaint alleging infringement of the patent.” When a petitioner is formally served in compliance with the Federal Rules, the application of the one-year rule is straightforward. But defendants often choose to waive service. When a defendant waives service, the date triggering the one-year rule, i.e., “the date on which the petitioner . . . is served,” is not clear. However, in three decisions concerning the issue of waiver (Macauto U.S.A. v. BOS Gmbh & KG,Motorola Mobility LLC v. Arnouse, and Scotts Comp. v. Encap), the Patent Trial and Appeals Board (PTAB) has consistently held that the service date for the one-year rule is the date the patent owner files the waiver of service with the court and only the filing of the waiver of service triggers the one-year rule. 

The PTAB’s rationale in each of these decisions finds its foundation in Federal Rule of Civil Procedure 4(d)(4), which states that “[w]hen the plaintiff files a waiver . . . these rules apply as if a summons and complaint had been served at the time of filing the waiver.” Accordingly, the date triggering the one-year rule could be much later than the date the patent owner filed the complaint, or the date the patent owner and the petitioner agreed to the wavier. Also, in situations where the patent owner does not file the waiver, the PTAB has concluded that “it has not established a service date,” so in those cases the one-year rule is not triggered at all. Macauto at 16. Finally, it is important to note that the waiver must be filed to establish service, even if the petitioner signed and returned the wavier of service. See Macauto at 16.

The key lesson from the PTAB’s decisions concerning waiver is that patent owners should always file a notice of waiver with the court. By performing this quick and simple task, patent owners can start the clock on the one-year rule and establish a date certain for the closing of the defendant’s window to file an IPR petition.