Does a notice letter guarantee a waiting period before suit?
No. Some owners sue the same week. Others negotiate for months. Treat any reply deadline in the letter as real for planning, but do not assume you have a fixed statutory pause before a complaint can be filed.
What clocks still matter for money even if suit can come soon?
Section 287 marking and actual notice rules can limit pre-suit damages when marking duties apply. Separately, 35 U.S.C. 286 generally limits recovery to six years before the complaint. Those rules affect damages windows; they do not freeze the owner's ability to file.
What if I am in a Hatch-Waxman or biosimilar path?
Drug and biologic statutes can create special notice and suit-timing structures (for example, Paragraph IV notice and related 45-day suit patterns in ANDA practice). See the Paragraph IV FAQ if that is your setting.
How should I plan while the letter is pending?
Assume suit is possible on short notice: preserve documents, map products, align insurers and suppliers, and decide whether PTAB, design-around, or license talks belong in the plan before papers land.