The problem
Imagine you are a small startup. You have spent years building a wearable AI device, you have filed a federal trademark application for your brand name, and your product is finally gaining traction. Then one of the most heavily funded technology companies on earth acquires a competitor, announces a product line under a name that sounds exactly like yours, and begins preparing a global launch. What do you do?
That is not a hypothetical. It is exactly what happened to IYO Inc., a Silicon Valley wearable-tech company that makes a screenless audio computer it calls the IYO One. IYO sued OpenAI, its CEO Sam Altman, Io Products Inc., and its founder Jony Ive in June 2025, one month after OpenAI acquired Io Products for $6.5 billion. The core allegation was straightforward: the name IO, used by OpenAI's new hardware subsidiary, was confusingly similar to IYO's registered mark.
The case moved fast. A federal district court granted IYO a temporary restraining order. The Ninth Circuit affirmed it in December 2025. OpenAI was banned from using "io" branding for AI-powered devices while the trademark infringement lawsuit moved forward. Then, in February 2026, OpenAI announced it was dropping the "io" branding for AI-enabled devices. By late July 2026, it was over: OpenAI Inc. and its hardware company Io Products Inc. settled the trademark infringement lawsuit brought by wearable tech-maker IYO Inc. The details of the settlement were not disclosed in the filing.
For startup founders evaluating a new brand name right now, this case is a masterclass in why a trademark availability check is not optional. It is urgent.
Analysis
The legal engine that drove this entire dispute is the concept of likelihood of confusion, and specifically its phonetic dimension. When courts evaluate whether two marks are confusingly similar, they do not just compare how the marks look on a page. They ask how consumers actually experience them: in conversation, in a podcast ad, in a retail environment, or in a voice search.
The court found that both the similarity of the marks and the relatedness of the goods favored IYO, as the marks IO and IYO "only differ by one letter and are pronounced identically." That is the crux. On paper, "IO" and "IYO" look different. Spoken aloud, they are homophones. IYO and IO are homophones, each pronounced "EYE-OH." A consumer hearing either name in an advertisement, a tech podcast, or a store demo would have no way to distinguish them by sound alone.
This is precisely what trademark lawyers call a phonetic trademark search or a sound-alike trademark check. It is one of the most commonly skipped steps when founders do a quick, free trademark search on their own. Most people type their proposed mark into the USPTO's search system and look for exact or near-exact spelling matches. But the law requires a much broader view. The likelihood-of-confusion analysis considers marks that are similar in appearance, sound, meaning, or commercial impression. Sound alone can be enough to block registration or trigger an infringement claim.
The district court found that IYO was likely to prove OpenAI infringes its trademark, and granted IYO's motion for a preliminary injunction barring OpenAI from using in commerce any mark confusingly similar to IYO's. That injunction carried real operational weight. It did not just threaten future liability. It stopped a $6.5-billion acquisition's flagship product from launching under its chosen name.
IYO, which creates devices that allow users to interact with smartphones, artificial intelligence, and the internet without screens, claimed Altman and OpenAI were aware of its brand since at least 2022 because the parties had discussed the possibility of collaboration. That detail matters enormously. The court's analysis was not purely about the marks in isolation. Evidence that the larger party had actual knowledge of the smaller brand strengthened the case for bad faith and made settlement far more likely than a drawn-out trial.
The goods-relatedness factor was equally decisive. The court concluded that the infringement was "sufficiently imminent" because IO had a working prototype, planned to compete with IYO, would market its product with the disputed mark, and intended to release the product in 2026. Both companies were building AI-powered, screenless computing devices. The closer the products, the lower the bar for proving confusion.
This story also illustrates that size does not protect you from trademark law, and it does not insulate you from a smaller competitor's rights either. A well-funded giant had to abandon a product name, drop branding across all marketing materials, and ultimately pay an undisclosed settlement sum, all because a startup had established prior rights in a phonetically identical mark. The lesson cuts both ways: if you are the smaller company, your registered mark is a real asset. If you are the larger company, skipping a thorough search before a major launch is an extraordinarily expensive shortcut.
For a deeper look at how courts evaluate these factors step by step, see our post on how likelihood of confusion works in trademark law.
The takeaway
A mark that looks different on paper can still be legally identical if it sounds the same. A phonetic trademark search is not a bonus step. It is a core part of any responsible trademark availability check. If you skip it, you may spend years and millions of dollars defending a name you could have screened in an afternoon.
What this means for founders
Here is the operational sequence every founder should follow before committing to a brand name:
- Search before you spend. Do not print business cards, file an LLC, build a website, or run a single paid ad until you have done at least a preliminary search. The question "is my business name trademarked?" needs an answer before you invest anything, not after.
- Go beyond exact spelling. When you search the USPTO database, do not just search your exact proposed name. Search phonetic variants, common misspellings, abbreviations, and acronyms. IO and IYO look different. They are legally the same sound. Your search must catch both.
- Check the goods and services category. A mark that is identical to yours in a completely unrelated industry is usually not a problem. A mark that sounds like yours and covers overlapping products or services is a serious risk. The IYO case turned partly on the fact that both companies were building AI-powered computing devices.
- Check for prior use, not just prior registration. Common-law trademark rights can exist even without a federal registration. A company that has been using a name in commerce since 2020 may have priority over your 2025 application, even if they never filed with the USPTO.
- Document your search process. If you ever face a dispute, showing that you conducted a good-faith, thorough search before adopting your mark is evidence that you did not act in bad faith. It matters at the TTAB and in federal court.
- Act early on registration. After a trademark application clears examination by the USPTO, the mark is published in the Official Gazette for a 30-day opposition period, giving the public notice that the mark is pending registration and an opportunity to challenge it before federal rights are granted. The sooner you file, the sooner you establish your priority date.
The IYO founders did not stop OpenAI with a bigger budget or a better legal team. They stopped them with a registered mark and a clear priority date. That is a tool available to every founder, at every stage, for a few hundred dollars in USPTO fees.
What this means for your attorney
When a client brings a proposed mark to a trademark attorney, the attorney's
FAQ
Is this legal advice?
No. This article is informational only and not legal advice.
Where should founders start?
Begin with a practical screening process in Trademark Search.
What should teams do before filing?
Review risk patterns, compare alternatives, and align on a filing plan in Pricing.
Informational disclaimer: this article is educational content and not legal advice.
Quick checklist
- Define naming goals and constraints.
- Screen for similar marks in adjacent categories.
- Compare top alternatives before committing.
- Document a clear go/no-go decision.
Related searches
Extend the analysis with a few adjacent checks: search the mark in neighboring goods and services, screen close phonetic variants, and look up the owners of any live conflicts to gauge how actively they enforce.
- Search the mark in neighboring goods and services.
- Screen close phonetic and visual variants.
- Look up the owners of any live conflicts to gauge enforcement activity.
Run your preliminary search
Do not commit budget to a name you have not screened. Run a preliminary trademark search on Imperium IP to surface conflicts and overlap before you spend, and bring the report to a licensed attorney via Find an Attorney when you are ready to file. A preliminary report costs a fraction of an attorney hour and can save you thousands later.
What should founders do if a match looks close?
Treat it as a review trigger and compare alternatives before proceeding.
How should teams prioritize multiple candidate names?
Rank names by defensibility, clarity, and strategic flexibility.
When should legal counsel be involved?
Involve counsel before filing and before major spend commitments.