When Must I File?

The short version

Filing deadlines attach to commercial events, not to legal ones. The decision here holds that selling the output of a secret process starts the clock on patenting that process, and that the America Invents Act did not change it.

It describes something that happens inside an ordinary commercial decision, which is why it arrives earlier than legal advice usually does.

Timing questions in patent law rarely announce themselves. They attach to decisions that look purely commercial at the time: ship the product, keep the method confidential, sign the standard employment agreement, leave and start something new.

Celanese is the sharp one for a company that has not filed anything yet. Keeping a manufacturing process secret while selling what it produces feels like the cautious choice. It is the choice that forfeited the patents.

Other events can start their own clocks: a publication, a public repository, a public use, an offer for sale, a foreign filing. This section covers the decided cases we have read from the opinions, so it will grow as more land rather than list every rule in the abstract.

The Decision

Decision Court Decided In one line
Celanese v. ITC Federal Circuit 12 August 2024 You cannot sell the output of a secret process for years and then patent the process.
Celanese v. ITC Celanese sold a sweetener made by a secret process for years, then filed on the process. The patents were invalid. Secrecy plus selling the output is the combination that cost them. Read the Case

What These Pages Do Not Decide

  • When any particular clock started, or whether one did. That depends on facts nobody here has seen.
  • Whether secrecy or filing is the better strategy for a given process. That is a business and legal judgment together.

Educational, not legal advice. Every quotation is verified against the court's own opinion. Consult a qualified patent attorney early, which in this area means before the commercial decision rather than after.

Frequently Asked Questions

How long does a US patent take?

For the typical filer, about two to three years. 54.9% of US utility applications filed in 2021 were granted within 36 months, and the median granted application took 27.2 months. The field matters more than anything else: 25.7% of biotechnology filings were granted within three years against 74.7% in communications. Abandonment is counted as a competing outcome and a few 2021 filings remain pending.

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