There is no single trademark API that does everything, which is the first thing worth knowing before you build one in. The US register, the EU register, and the 70-plus offices in between each expose their data differently, and each comes with a catch. Here is the honest map of what is available in 2026, and where each option leaves you stranded.
Key takeaway: the data exists and most of it is reachable, but the gap between "an API exists" and "trademark search that works in your product" is wide, and that gap is where almost all the real effort goes.
The USPTO: free, official, and quirky
The US Patent and Trademark Office publishes its trademark data for free. You can pull the full record for a known mark, and there is bulk data for the entire register. The catch is that it was built for examiners and attorneys, not for your app: no clean fuzzy or phonetic search, heavy formats, and real rate limits. It is a foundation, not a finished feature. We go deeper on its specific traps in the USPTO trademark API, up close.
EUIPO and TMview: breadth, with a hole
For Europe, EUIPO exposes the EU register. For everywhere else, TMview is the closest thing to a universal source, one search across more than 70 national offices, the UK included. It is genuinely broad. The hole: it is built around the mark and the owner, not the representative, and coverage and freshness vary office by office. If you need every mark filed by a particular firm, TMview will not hand it to you cleanly.
Commercial APIs: convenience you rent
A handful of paid providers wrap all of this in one tidy API, with phonetic matching and firm-level aggregation already done. They are the fastest route to a working feature, and you pay per call or per seat for it. Worth it when speed matters more than cost, a poor fit when your volume is high or your use case is narrow. Picking the right one, and not overpaying, takes someone who has used several.
So which one?
It depends entirely on what you are building. A name check at signup, a clearance step, brand monitoring, a directory ranked by filing volume, each points to a different source, or a blend of them. There is no right answer in the abstract, only the right answer for your product, your coverage needs, and your budget.
The part nobody quotes you for
Choosing the API is the easy decision. The work is everything after: normalising messy data, adding the fuzzy matching the official sources lack, caching so you are not hammering a rate-limited endpoint, and keeping it alive when an office quietly changes its format. That is the difference between a demo and something you can put in front of customers.
We know, because we built it. The free trademark check here runs live USPTO searches. The business name generator clears names against global registers. Both are ours, on the same stack we would build yours with.
If you want trademark search, clearance, or monitoring inside your own product, the quickest path is not a six-week spike into TSDR and TMview. It is a short conversation. See how we integrate trademark data, tell us the use case, and we will tell you which source fits and what it takes to ship.