There is a big difference between owning a brand name in your head and owning it on the trademark register. The dispute between Anthropic, the company behind Claude, and Abnormal AI is a live, real world example of what that difference can cost, and it answers a question we hear from business owners every week: do I really need to register my trademark if I was using the name first?
If you missed the background, our earlier article covers the dispute in full: When Your Competitor Copies Your Logo: The Anthropic v Abnormal AI Case.
The eight month gap at the heart of the dispute
Both companies operate in the AI space, and both use a variation of “AI” in their branding. The timeline is what makes this case such a useful lesson.
Abnormal AI filed its trademark application on 12 March 2025. Anthropic did not file until November 2025, roughly eight months later. Anthropic is now relying on a claim that it was first to use the name, with first use claimed from May 2021.
In other words, a business with years of use behind its name is having to argue its case in court because someone else reached the register first. That is the gap between using a name and owning it.
First to file vs first to use: why the rule matters
The registered trademark is usually what courts, customs authorities and enforcement agencies act on. The key question is what happens when the person on the register is not the person who used the name first.
The United States gives common law protection to first use, so a business that can prove earlier use of a mark has a genuine route to challenge a later filer. That is why Anthropic could well succeed in this dispute.
Most of the world does not work that way. The majority of territories operate on a first to file basis. If someone else registers your name first, your earlier use may count for very little. You are often left arguing bad faith, meaning that the other party registered the mark knowing full well that a confusingly similar mark was already in use. Bad faith claims can succeed, but they are slower, more expensive and far less certain than simply being first to the register.
The UK sits somewhere in between. Unregistered rights do exist here through passing off, but proving passing off means evidencing goodwill, misrepresentation and damage. It is a much harder and costlier road than pointing to a registration certificate.
The real cost of waiting to register a trademark
The cost of waiting is not just the legal fees that pile up when a dispute starts. It is the risk that the name you have built becomes unavailable on the register before you protect it.
The longer the gap between “we are using this name” and “we have filed for it”, the bigger the opening someone else can squeeze through. That someone might be a competitor, an opportunist who watches new brands gain traction, or simply another business that landed on a similar name honestly.
As our founder Jonathan Paton put it when discussing the case: “If you believe in the brand you are building, why wouldn’t you invest in owning it?”
A registered trademark is an asset, not an admin task
A registration does more than protect you. It creates a standalone business asset. A registered trademark can be valued, licensed, used as security and even sold on its own. If you ever left an industry, the trademark itself could be sold to a competitor. Few investments of a few hundred pounds create an asset that can appreciate with your brand.
What this means if you sell in more than one country
Trademark rights are territorial. This is the part that catches growing businesses out most often.
A UK founder selling into the US needs a US registration. A global business selling into the UK needs a UK registration. Registering at home does not protect you in the markets you are expanding into, and in first to file territories the window closes the moment someone else applies.
If you are already trading in, or about to enter, other markets, our international trademark registration service covers filing strategy across the territories that matter to you.
How to close your own gap
The question worth asking, whether you are a startup or an established business, is simple. How many months or years sit between your first use of your name and your first filing? And in how many territories are you selling without protection?
If the answer makes you uncomfortable, start with a free trademark search to check whether your name is still clear, then get it protected through our UK trademark registration service. Being first to file is cheaper, faster and safer than being first to court.
Not sure where your brand stands? Call The Trademark Helpline on 0161 833 5400 and one of our specialists will talk you through it, with no obligation and in plain English.
