You are all familiar with ChatGPT, the famous AI tool developed by OpenAI that can generate text autonomously.
However, “ChatGPT” is in itself only a term describing the service offered by OpenAI, since it is a chat tool using ‘Generative Pre-trained Transformer” technology, and whose acronym is none other than “G.P.T. ”.
As a result, when OpenAI sought to protect the “GPT” sign it attaches to its “Chat” under trademark law in 2022, it encountered numerous obstacles that it had probably not anticipated.
The saga of the “GPT” trademarks began in the United States. OpenAI suffered successive refusals of its “GPT” trademark applications by the United States Patent and Trademark Office (USPTO). Admittedly, following the USPTO's latest refusal in February 2024, OpenAI asked it to reconsider its decision and the proceedings are still ongoing, but the trend towards refusal is not only national, it is more global.
In fact, on 17 October 2025, the Cancellation Division of the European Union Intellectual Property Office (EUIPO) issued four decisions (C 64 174, C 64 300, C 64 301 and C 64 175) concerning the trademarks GPT, GPT-3, GPT-4 and GPT-5 registered by OpenAI, in particular for software and computer services related to artificial intelligence (classes 9 and 42). The EUIPO declared the GPT, GPT-3 and GPT-4 trademarks to be completely invalid and the GPT-5 trademark to be partially invalid.
The EUIPO's reasoning is similar to that of the USPTO: it considers that the acronym “GPT” has become a generic technical term designating a language model (LLM) architecture based on machine learning, which has become a standard in the field of artificial intelligence.
The distinctiveness of a trademark is assessed in relation to the relevant public, i.e. those to whom the trademark is addressed.
The EUIPO refers here to an English-speaking public consisting of IT professionals and specialised users, who would perceive the sign “GPT” as describing a technical feature of the software covered by the protection of that trademark. As such, it is not a distinctive sign but a descriptive sign.
OpenAI put forward several arguments to challenge this distinctiveness, in particular by arguing that the generalisation of the term GPT (Generative Pre-trained Transformer) was subsequent to its trademark applications. However, the EUIPO points out that the term was already in use within the scientific and technical community prior to or at the same time as its trademark applications. As for numbers 3, 4 and 5, they do not have any distinctive character of their own and correspond to version numbers used in IT development.
The nuance introduced by the only partial invalidity of the “GPT-5” trademark relates to the protection of other products that are distinct from the three other trademarks and have no connection with artificial intelligence (e.g. diving equipment, etc.). The EUIPO may therefore partially cancel a trademark when it is not descriptive for some of the goods and/or services covered, which was the case with the trademark “GPT-5”.
Through these four decisions, the EUIPO thus reiterates that the role of a trademark is to identify the commercial origin of goods and services and that, as such, any attempt to include a technical description is futile.
The direct consequence of the cancellation of these “GPT” trademarks is the lack of protection for the term “GPT” used by OpenAI. As such, if these decisions become final, any competitor will be able to use the term “ChatGPT” to offer competing solutions. An appeal is still possible for OpenAI and, given what is at stake, it would be surprising if OpenAI had said its last word in the “GPT” trademark saga.
These EUIPO decisions are an opportunity to recall that, in itself, it is not too complicated to file a trademark, but it is more difficult to file a good trademark that will pass the registration stages and withstand the test of time. Once you have launched your products or services under a trademark, it is difficult to backtrack and change it. It is therefore preferable to anticipate problems as early as the trademark filing stage.