If you believe someone infringed your patent, timing matters. U.S. patent law sets firm limits on when you can file a claim. Understanding these deadlines helps you protect your rights and avoid losing potential damages.
The statute of limitations for patent infringement
Federal law controls patent infringement claims. Under U.S. law, you can file a lawsuit at any time while the patent remains valid. However, the law limits how far back you can recover damages.
You may seek damages only for infringement that occurred within six years before you file the lawsuit. If the infringement started earlier, the court will not award damages for that older conduct. This rule makes early action important once you spot unauthorized use.
Why waiting can reduce your recovery
Delays can cost you money. Even if infringement continues for many years, the six‑year limit caps the damages period. You could miss compensation for early sales, licensing fees, or lost profits.
Waiting can also weaken your position. Evidence may disappear, witnesses may forget details, and business records may become harder to obtain. Acting sooner helps preserve proof that supports your claim.
How ongoing infringement affects deadlines
Ongoing infringement resets the damages window but not the filing right. Each act of infringement creates a new opportunity to recover damages within the six‑year look‑back period. This means you can still pursue recent infringement even if earlier acts fall outside the limit.
You should also watch the patent expiration date. Once the patent expires, infringement claims stop accruing. You can still sue for past infringement, but only within the allowable damages period.
Steps to take when you discover infringement
Once you identify potential infringement, gather records that show use, sales, and timelines. Keep copies of marketing materials, product samples, and online listings. These details help establish when infringement occurred.
Tracking dates allows you to assess how much recovery may remain available. Prompt evaluation puts you in a stronger position if litigation becomes necessary.
Understanding your filing timeline
Patent infringement claims do not expire like many other lawsuits, but damages limits apply. The six‑year rule shapes how much compensation you can pursue. Knowing this timeline helps you make informed decisions about protecting your intellectual property.