--- title: Anthropic Is Sued Over Five AI Patents Days Before Its IPO, Adding to Copyright, Antitrust and Consumer Cases description: Flinn AI Technologies sued Anthropic over five AI patents on November 12, six days before its IPO prices. Copyright, antitrust and consumer cases are also open. author: Darie Nani (Editor-in-Chief) date: 2026-11-13T18:19:58.889Z updated: 2026-11-13T18:19:58.896Z canonical: https://www.sovereignmagazine.com/article/anthropic-patent-lawsuit-ipo-court-cases image: https://cdn.nanimediahouse.com/dario-amodei-anthropic-patent-lawsuit.webp categories: Artificial Intelligence, Legal content_type: News region: United States publication: Sovereign Magazine about: - type: Organization name: Anthropic description: American artificial intelligence company that develops the Claude models. --- Anthropic was sued for patent infringement on Thursday, six days before the Claude maker is expected to price an initial public offering that would value it at as much as $1.02 trillion. Flinn Artificial Intelligence (AI) Technologies, a Texas company, filed the case in federal court in Delaware on November 12 and a separate one against OpenAI the same day. Each complaint asserts five patents on attention-based neural network technology, issued to the co-inventors Steven Flinn and Naomi Moneypenny. It is the second patent case filed against Anthropic in four months, after one from the University of Tennessee Research Foundation in July. Also on Thursday, four nonprofits named Anthropic and four other companies in a California lawsuit that [asks a court to freeze the development of more capable AI models](https://www.sovereignmagazine.com/article/ai-labs-sued-slowing-down-not-stopping). Anthropic [began marketing its shares at $70 to $78 each](https://www.sovereignmagazine.com/article/anthropic-ipo-price-range-roadshow) on November 10. Pricing is expected on November 18, with trading on Nasdaq under the ticker ANT starting the next day. ## The Flinn Patents Trace Back to Applications Filed in 2015 and 2016 All five patents carry the title "Iterative attention-based neural network training and processing" and were granted between February and December 2025, according to US patent records. They trace back to applications filed in late 2015 and early 2016, and the complaints say the technology they describe is now used in important functions of generative AI systems. The transformer, the design on which Claude, ChatGPT and other large language models are based, was set out by Google researchers in a 2017 paper titled "Attention Is All You Need." Patent records list ManyWorlds Inc. as the original owner of other patents by the same two inventors. A separate company that now holds some of those, Many Worlds 2T Innovations, sued OpenAI in federal court in Texas on August 31 over five patents covering retrieval, personalization and content generation, IPWatchdog reported. ## Anthropic Tells Investors to Expect More Patent Claims > "We also face patent infringement claims, which may seek substantial damages or injunctive relief limiting our ability to use certain technologies, and we expect such claims may increasingly be asserted as our public profile grows." > — Anthropic, amended prospectus, November 10, 2026 The warning appears among the risk factors in the [amended prospectus](https://www.sec.gov/Archives/edgar/data/2130357/000162828026072484/anthropicpbc-sx1ax2.htm) Anthropic filed two days before the Flinn case. The company adds that some of its competitors "hold substantially larger patent portfolios than we do," which could limit its ability to answer a claim with patents of its own, and that "non-practicing entities and individuals" may claim to own rights relating to its technology. The filing also says certain agreements require the company to defend and indemnify the other party, "without a cap on our liability," against claims that its models or their outputs infringe someone else's intellectual property. The prospectus does not name any patent case. In the first, filed in Delaware in July, the University of Tennessee Research Foundation asserts two patents on neural network technology developed by its researchers and accuses Claude Code, Anthropic's coding tool. It asks for damages and an injunction, The Next Web reported, citing Bloomberg Law. Anthropic has asked the court to dismiss that case, according to AI Lawsuit Tracker, a site that follows the dockets. Facebook was sued over patents at the same stage. Yahoo filed a case over 10 patents in March 2012, weeks after Facebook filed to go public, and the two settled that July with a licensing and advertising agreement and no payment. ## Copyright Cases Make Up Most of Anthropic's Court List Before Thursday, AI Lawsuit Tracker counted 21 cases filed against Anthropic, 17 of them over copyright. Anthropic agreed in September 2025 to pay $1.5 billion to settle the largest of them, the Bartz class action brought by authors, and the district court approved the settlement in July 2026. The company paid $300 million of that in 2025 and still carried $450 million as a liability on September 30, its prospectus shows. The music publishers' cases are continuing. Concord Music Group filed first, in October 2023, and the prospectus lists further complaints between January and October 2026 from publishers including Universal Music Publishing Group, BMG, Round Hill Music, Sony Music Publishing and Warner Chappell Music. They allege that Anthropic copied song lyrics and compositions to train its models. Reddit is suing separately in a California state court over the collection of posts from its platform. "In each of the actions, we believe we have meritorious defenses and dispute any allegation of wrongdoing," Anthropic says in the filing. Jason Winmill of Buying Legal Council told Bloomberg that the prospectus's legal risks, "while logically grouped and well organized, are daunting and sobering." ## Anthropic Also Discloses an Antitrust Class Action and an FTC Demand The prospectus describes a class action filed in September in federal court in San Francisco, in which subscribers allege that Anthropic and other AI developers agreed to slow the pace at which they improve their models, in breach of the Sherman Act. The plaintiffs want triple damages and an injunction. "We disagree with the claims and intend to defend the matter vigorously," Anthropic wrote, while warning that "the outcome of this and any similar proceeding is inherently uncertain." In October the Federal Trade Commission sent Anthropic a civil investigative demand for information about its consumer protection, data protection and privacy practices and the safety and security of its products. The filing says the demand "does not assert any claims against us." Subscribers are also suing over the usage limits on Claude Max plans, and on November 6 a federal judge [allowed three of their claims to go ahead](https://www.sovereignmagazine.com/article/claude-max-lawsuit-ruling). The plaintiffs have until December 2 to amend their complaint. Anthropic is the plaintiff in one of the disclosed cases. It sued the Department of War after the department designated it a supply-chain risk, and won most of that case in a California federal court in August. In September a federal appeals court in Washington upheld one of the designations by two votes to one, and Anthropic has asked the full court to rehear it. The nonprofits' lawsuit and the Flinn case were both filed after the November 10 prospectus, so neither appears in it. Find out more at [anthropic.com](https://www.anthropic.com). ## FAQ **Q: Is the Anthropic lawsuit real?** There are several. The newest is a patent case filed by Flinn AI Technologies in federal court in Delaware on November 12, alongside a separate one against OpenAI. Anthropic also faces copyright cases from music publishers, an antitrust class action, a class action over Claude Max usage limits and a lawsuit from four nonprofits that want AI development frozen. Its prospectus says it disputes any allegation of wrongdoing. **Q: What is happening with the Anthropic settlement?** Anthropic agreed in September 2025 to pay $1.5 billion to settle Bartz, a class action brought by authors over the use of their books, and the district court approved the settlement in July 2026. The company paid $300 million in 2025 and still recorded $450 million as a liability on September 30, 2026. The settlement does not cover the music publishers' cases, which continue. **Q: Is Anthropic going IPO?** Yes. Anthropic is marketing its shares at $70 to $78 each, which would value it at between $916 billion and $1.02 trillion. Pricing is expected on November 18 and the shares are due to begin trading on Nasdaq under the ticker ANT on November 19. The prospectus lists litigation among the risks, including patent claims the company expects to increase.