Cerence Inc., a leading provider of artificial intelligence and text-to-speech technology, has filed a lawsuit against Microsoft Corp. and its subsidiary Nuance Communications Inc. in the U.S. District Court for the District of Delaware. The lawsuit alleges copyright infringement and breach of contract, accusing Microsoft and Nuance of continuing to sell licenses and use Cerence’s text-to-speech (TTS) technology without authorization.

The legal action follows the expiration of a five-year licensing agreement between Cerence and Nuance in September 2024. Despite Cerence’s clear warnings that the license would not be extended, Microsoft and Nuance have allegedly continued to sell additional licenses for Cerence’s TTS technology and use the technology without consent.

According to Cerence’s complaint, the expired license allowed Nuance to distribute products incorporating the TTS technology to third parties in object code form and use the technology internally. However, after the expiration of the license, Cerence asserted that Nuance had no right to distribute additional licenses to new or existing customers. Microsoft acquired Nuance in 2022 and subsequently indicated its intention to transition Nuance’s customers to Microsoft’s cloud-based TTS technology. Despite this transition, many Nuance customers have not migrated, leading Cerence to attempt to extend the license agreement. After unsuccessful negotiations, the license expired in September 2024.

Cerence alleges that Microsoft and Nuance have continued using the TTS technology post-expiration, including selling additional object code TTS licenses to their customers. The complaint also highlights the January 2025 announcement that Microsoft planned to transfer Nuance’s professional services business to HCLTech, which Cerence argues included certain licensed TTS technology, violating the terms of the original license.

Jennifer Salinas, Chief Administrative Officer and General Counsel at Cerence, emphasized the company’s commitment to protecting its intellectual property. "We are deeply committed to having our intellectual property rights respected and enforced, especially as we expand into new markets beyond automotive. This action against Microsoft and Nuance is necessary to protect our investments, as well as our long-standing culture of innovation."

The case, titled Cerence Inc. et al. v. Microsoft Corporation et al., is filed under case number 1:25-cv-00553. Cerence is represented by Andrew C. Mayo and Brian A. Biggs of Ashby & Geddes, along with Brian M. Daucher, Gazal Pour-Moezzi, and Edwin Komen of Sheppard Mullin Richter & Hampton LLP.

Cerence seeks to enforce its intellectual property rights and is determined to defend its interests in the ongoing dispute.