ChatGPT cannot run a reliable trademark search on its own: it has no trademark register behind it (an office's official database of applications and registrations), so its answer to "is this name taken?" has not been checked against one. Connected to Signa, a ChatGPT trademark search is answered from live office records: 64.6 million of them across 15 offices (Signa data, queried 2026-11-09), with application numbers, dates and owners you can check against the office. That is register data, not a clearance opinion.
Below: the setup (no code), four prompts with the data they returned on 2026-11-09, and the limits.
Can ChatGPT do a trademark search on its own?
OpenAI's help article Does ChatGPT tell the truth? says ChatGPT can be wrong while sounding confident, including incorrect dates and fabricated references, and that answers miss events after the model's knowledge cutoff unless a tool is used. In trademark terms, a registration number can look right and match no record.
Web search, on by default, finds current pages that mention a name, with citations. But a web page is not a register query: no filter by class, status or office, and OpenAI notes the model may be unable to read a given site because of technical issues, paywalls or robots.txt.
Registers also move. Of Signa's 15 offices, 11 sync daily and 4 weekly (Signa data, queried 2026-11-09), and the opposition window in prompt 3 closes on 2026-11-12.
To be fair to ChatGPT, explaining concepts needs no register. For the manual route, see how to check if a name is trademarked. For the wider picture, see AI trademark search.
How to connect Signa to ChatGPT
Signa runs a hosted server at https://api.signa.so/mcp: nothing to install, nothing running locally. The Signa for ChatGPT page has the URL, and Signa's docs cover the details.
Who can set it up. Per OpenAI, custom MCP servers work on ChatGPT Business and Enterprise/Edu, and on Pro with read/fetch permissions. Free and Plus are not listed, and it is web only. On Business, only admins and owners create and publish the connection; Enterprise/Edu admins can also grant members permission. Members then find it under Settings > Plugins.
OpenAI's current steps:
- Go to Plugins.
- Select the plus button, then Add custom MCP server.
- Name it
Signa. - Under Connection, enter
https://api.signa.so/mcp. - For authentication, choose OAuth.
- Review the risk warning and check "I understand and want to continue".
- Select "Create as a plugin", then review the discovered tools.
Signa's docs describe the older path, Settings > Connectors > Create (with Developer mode), in case your workspace still shows it. OpenAI says the current Plugins path does not need Developer mode first.
OAuth is a sign-in at app.signa.so to approve access. No key to paste, and every query runs as your Signa organization. OpenAI advises connecting only servers you trust, because untrusted ones raise risks such as prompt injection.
To test it, start a new chat, type @, select the plugin, and ask:
Use Signa to search for NIKE trademarks in the US.
You should see a search_trademarks call and live USPTO results.
Four trademark search prompts for ChatGPT, with real results
You never need to name a tool; Signa's docs say the assistant picks them. Per OpenAI, an @ selection covers only that message, so @mention Signa again when a follow-up needs new data. ChatGPT's wording varies, so what follows is the data returned.
1. Is a similar name already on a trademark register?
Use Signa to search for trademarks similar to DUOLINGO.
search_trademarks ranks resembling records by tier. The first 100 rows: 43 identical (mostly Duolingo, Inc.'s own), 11 near_identical, 46 similar.
| Office | Mark | Owner | Nice classes | Filed | Status |
|---|---|---|---|---|---|
| US | DUOLINGO (4588574) | Duolingo, Inc. | 9, 41 | 2014-01-21 | Registered |
| EM | DUOLINO (010130491) | Kermi GmbH | 11 | 2011-07-18 | Registered |
| FR | DUOLIGO (3883342) | Compagnie Financiere et de Participations Roullier | 1, 5 | 2011-12-20 | Registered |
| EM | DUOLINO (011477668) | Société des Produits Nestlé S.A. | 29, 30 | 2013-01-10 | Expired |
| US | DUMPLINGO (8147933) | Canada Dumplings Inc. | 29, 30, 35, 43 | 2022-06-17 | Registered |
Signa data, queried 2026-11-09. Similar-name search for DUOLINGO, all offices, first 100 rows. The EM and FR rows are near_identical, DUMPLINGO similar.
Nice classes are the international system for sorting goods and services into numbered categories: Class 9 covers software, Class 41 education. Near-identical marks in classes 11 and 1 sit beside a language app in classes 9 and 41. Same word, different goods: a tier ranks resemblance, not legal conflict. This first pass is a knockout search, the start of a trademark clearance search.
2. Who has filed an exact name?
Use Signa to find every trademark with the exact text CHATGPT, in all offices. Who filed them?
The exact-text filter returned 56 records across 13 offices, variants included (CHATGPT 33, ChatGPT 16, CHAT GPT 6, CHAT-GPT 1). Mexico (13) and Brazil (12) hold more than the US (9).
OpenAI owns 29: 12 registered, 8 in an opposition period or pending opposition, 4 in examination, 2 filed, 1 published, and 2 WIPO international registrations with mixed status. Other owners hold 27, none registered.
Records with the exact text CHATGPT by office, OpenAI vs other owners
| Office | Number | Owner | Filed | Status |
|---|---|---|---|---|
| US | 97719809 | Brand Central, LLC | 2022-12-15 | Abandoned |
| GB | UK00003879168 | State Bull Company Limited | 2023-02-17 | Cancelled |
| MX | 2898892 | Site Matrix, LLC | 2023-02-23 | Abandoned |
| US | 97931268 | ChatGPT Artificial Intelligence Institute Inc | 2023-05-11 | Abandoned |
Signa data, queried 2026-11-09. Mark text is exactly CHATGPT, all offices. Other owners' 27: abandoned 14, withdrawn 5, refused 3, cancelled 1, pending 4.
ChatGPT launched on 30 November 2022. Brand Central filed 11 days before OpenAI's earliest record here (2022-12-26), and most third-party filings landed between December 2022 and April 2023. Filing first did not mean winning. An exact-text hit shows who filed and what happened, not who holds rights.
3. Can a trademark application still be opposed?
An opposition period is the window after an office publishes an application when third parties can formally object. See the trademark opposition guide.
Use Signa to find US applications similar to OPENAI that are open for opposition. When does the window close?
search_trademarks filters on opposition status; get_trademark, get_trademark_events and get_opposition_rules supply the window, timeline and rule. Two rows: OPENAI, and OPENAQ (US 99505597, OpenAQ Inc., near_identical).
| Field | Value |
|---|---|
| Mark | OPENAI, US serial 99025123 |
| Owners | OpenAI, Inc. and OPENAI FOUNDATION |
| Nice classes | 9, 35, 38, 41, 42, 45 |
| Filed | 2025-01-31 |
| Published | 2026-10-13 |
| Window opens | 2026-10-14 |
| Window closes | 2026-11-12, US Eastern time |
| Extension | 30 days as of right on timely request; total capped at 180 days from publication |
Signa data, queried 2026-11-09. Similar-name search for OPENAI, US, open for opposition.
The timeline, in the office's labels: "APPROVED FOR PUB - PRINCIPAL REGISTER" (2026-09-14), "PUBLISHED FOR OPPOSITION" (2026-10-13), "EXTENSION OF TIME TO OPPOSE RECEIVED" (2026-10-20).
The computed window closes 2026-11-12, three days after this snapshot. Someone has already asked for more time, so the date that matters for that party is later. The computed window is the default under 15 U.S.C. § 1063(a), with extensions under 37 CFR § 2.102; the timeline shows what was actually filed.
4. Which Nice classes does a product need?
Use Signa to suggest Nice classes for a meal-kit delivery service with a recipe app.
suggest_classifications returns ranked classes with confidence and a reason.
| Class | Confidence | Type | Reason given |
|---|---|---|---|
| 39 | High | Core | Delivering meal kits (packaging and delivery of goods) |
| 9 | High | Core | The recipe app as downloadable software |
| 30 | Medium | Conditional | Only if the kits are food products in their own right |
| 35 | Medium | Adjacent | Selling your own kits online is retail; defensive filing |
Signa data, queried 2026-11-09. Input: "a meal-kit delivery service with a recipe app".
Class 30 hinges on a product decision: making your own sauces or prepared meals, or only delivering others' goods. The Nice classification reference lists every class.
What a ChatGPT trademark search still cannot do
As of 2026-11-09:
- Only covered offices. 15 offices, 64.6 million records (Signa data, queried 2026-11-09). A clean result says nothing about other countries. The list changes; ask ChatGPT to list Signa's offices (
list_officesis free). - No unregistered marks. Common-law marks gain rights through use and sit in no register. A common-law search is separate.
- Not a legal conclusion. A tier is not likelihood of confusion. Consult a trademark attorney for legal guidance specific to your situation.
- ChatGPT can misread the data. The summary is ChatGPT's; check numbers that matter against the office record.
- Proceedings in five offices: US, EUIPO, Canada, Australia, Singapore.
- No official fees. Use each office's fee schedule.
- Search and read only. Signa's integration page lists the connector's capabilities as Search and Read. Monitoring watches are a developer setup through the API.
- Plan and platform. Per OpenAI: Business, Enterprise/Edu and Pro (read/fetch), web only.
- Metered usage. Searches and class suggestions cost 10 Signa credits per call, reads 1 per record or page, from the same balance as the API. Office lookups are free and failed calls are not charged. Signa has a Free plan (pricing).
Run your first ChatGPT trademark search
Connect Signa from the ChatGPT integration page, ask about the name you care about most, and take what you find to a trademark attorney. Claude users can follow the Claude trademark search guide. Developers can start at docs.signa.so/ai/mcp.