How to Use Claude for Trademark Search (With Real Register Data)

Claude can run a trademark search, but only once it is connected to a trademark register (an office's official database of applications and registrations). On its own it has no built-in connection to one, so nothing it tells you about a name has been checked against a register. Connect Signa to Claude and a question about a name is served by live records from 11 trademark offices (the live list on 2026-10-13), with application numbers, dates and owners you can check against the office itself. That is an AI trademark search of register data, not a clearance opinion.

This guide covers how to connect (no code), six questions to ask with the data that came back on 2026-10-13, and what a connected Claude still cannot do.

Can Claude do a trademark search on its own?

Anthropic documents two of these three gaps itself.

• No register. Claude has no built-in connection to a trademark register. A question about whether a name is taken gets no register lookup behind it.
• A knowledge cutoff. Anthropic states that each Claude model has a knowledge cutoff and may not be aware of events after it.
• Plausible output with nothing behind it. Anthropic's support page on incorrect or misleading responses says Claude can produce such output, may lack up-to-date information, and should not be relied on as a singular source of truth. In trademark terms, a registration number or a filing date can look right and match no record.

The cutoff matters more here than in most subjects, because registers move every day. Of the 11 offices Signa covers, 8 sync daily and 3 weekly (Signa data, queried 2026-10-13, all offices).

One example: Apple Inc. filed APPLE ADS at the USPTO (the US trademark office) on 2026-07-17, the office published it on 2026-09-29, and the period for objecting to it closes on 2026-10-29. A question with a 30-day shelf life cannot be served by knowledge that stops at a cutoff date.

To be fair to Claude, the gap is data, not reasoning. Explaining a concept needs no register: what a class is, how a word mark differs from a logo, what an opposition period is. For the manual route, see how to check if a name is trademarked.

How to connect Signa to Claude for trademark search

Signa runs a hosted server at https://api.signa.so/mcp. Nothing to install, nothing running on your machine. There are two ways to add it. Both start from the Signa for Claude page, which has the directory link and the server URL to copy.

From Claude's connector directory. Signa is listed at claude.ai/directory/signa. Anthropic's connector guide gives these general instructions for any directory connector:

1. Open Customize > Connectors.
2. Click the + next to Connectors.
3. Browse to the connector and click it.
4. Click Connect and follow the authentication prompts.

As a custom connector. The menu labels in these steps are Anthropic's current ones, from its custom connector article. Signa's connection docs describe the same page as Settings → Connectors, in case your app shows that label.

1. Open Customize > Connectors.
2. Click "+ Add", then "Add custom connector".
3. Name it Signa and enter the URL https://api.signa.so/mcp.
4. Click Add (Signa's docs call this step Save), then click Connect and complete the browser login.

The login is a sign-in at app.signa.so where you approve access. There is no key to paste, and every query runs as your Signa organization. On Team and Enterprise plans, Anthropic says an Owner or Primary Owner adds the connector under Organization settings > Connectors first; members then open Customize > Connectors and click Connect.

According to Anthropic, custom connectors are available on Free, Pro, Max, Team and Enterprise plans, and Free users are limited to one. Anthropic also warns that custom connectors link Claude to services it has not verified, and that you should only connect to servers you trust. That warning applies to Signa like any other server.

Anthropic's connector guide describes two controls. In a chat, the + menu > Connectors lets you toggle which services that conversation can use. Each connector's tools can be set to Always allow, Needs approval, or Blocked.

To verify the connection, Signa's docs suggest this prompt:

Use Signa to search for NIKE trademarks in the US.

You should see Claude call the search_trademarks tool and return live USPTO results. If you get 401: Access token missing org_id claim, the Signa account has not finished onboarding: log in at app.signa.so and create an organization.

Six trademark search prompts for Claude, with real results

You never need to name a tool. Signa's docs say the assistant picks the right ones automatically. The names appear here so you can recognize them if a tool is set to Needs approval. Claude's wording varies, so what follows is the data the tools returned, not a transcript.

1. Is a similar name already on a trademark register?

Use Signa to search for trademarks similar to PATAGONIA.

This is served by search_trademarks, which ranks records that resemble the name and tags each one with a match tier. All of the first 100 rows came back in the identical tier, and they do not belong to one company. Six of them:

Signa data, queried 2026-10-13. Similar-name search for PATAGONIA, all offices, first 100 rows. All six rows are registered.

Nice classes are the international system for sorting goods and services into numbered categories: Class 9 covers software, Class 25 covers clothing. Registered PATAGONIA records cover tires (Class 12, Tireco), beer (Class 32, Labatt) and alcoholic beverages other than beer (Class 33, Viña Concha Y Toro) next to Patagonia, Inc.'s own, because the same word can generally be registered by different owners for different goods.

The chart shows the size of the full result. These 895 records are Signa's count behind the same search, taken from Signa's API directly; Claude does not return this table. The USPTO holds 350 of them, 39% of the total, and only 366 of the 895 are registered. Of the other 529, 506 are abandoned, expired, cancelled, refused, withdrawn or surrendered, 16 are still pending and 7 have no clear status (Signa data, queried 2026-10-13; similar-name search for PATAGONIA, all offices, any owner, one row per record).

Too many to read, so narrow it:

Only registered US marks in class 25.

The same tool, now filtered by office, class and status, returned 6 records. Five are PATAGONIA registrations owned by Patagonia, Inc. (1811334, 1189402, 1294523, 6761328, 7779345). The sixth is CONSERVACION PATAGONICA, registration 3319048, owned by Tompkins Conservation, in the similar tier (Signa data, queried 2026-10-13; similar-name search for PATAGONIA, US, class 25, registered).

That sixth row is what an exact-match search would miss. This is what practitioners call a knockout search, the first pass of a trademark clearance search.

2. Where is an exact name registered as a trademark?

Use Signa to find every trademark with the exact text SPOTIFY, in all offices.

search_trademarks again, with an exact-text filter in place of similarity ranking. It returned 17 records, all owned by Spotify AB.

Signa data, queried 2026-10-13. Filter: mark text is exactly SPOTIFY, all offices.

The oldest two were filed in Sweden on 2006-08-08. The newest is Australian application 2508537: filed 2024-12-19 in 13 classes, published 2026-10-06, carrying the office label "In opposition period", with a window that closes on 2026-12-07.

Signa groups international registrations (one WIPO filing that can extend to many countries) under WIPO. So the missing rows for France, Switzerland, Norway and Singapore mean only that Signa returned no separate national record with that exact text. They say nothing either way about whether a WIPO registration extends to those countries.

3. What trademarks does a company own?

Use Signa to show Patagonia, Inc.'s trademark portfolio and its five most recent filings.

Three tools serve this: list_owners finds the owner, get_owner returns portfolio statistics, and get_owner_trademarks lists the records. The US owner record for Patagonia, Inc. holds 308 records: 120 registered, 4 pending, 68 cancelled and 116 abandoned, with filings running from 1980-03-31 to 2025-11-03.

Signa data, queried 2026-10-13. Filter: owner record Patagonia, Inc. (US), newest filings first. Portfolio statistics computed 2026-09-09.

That count is one owner record, not the company. Offices spell and store owner names differently, so ask the follow-up:

Now show the whole company across all offices.

get_entity resolves the company: 630 records, 379 of them active, built from 11 linked owner records across 9 offices (Signa data, queried 2026-10-13; resolved company record for Patagonia, Inc.). The US owner record holds 308 of those 630 records, or 49%.

4. Can a trademark application still be opposed?

An opposition period is the window after an office publishes an application, during which third parties can formally object before it registers. The guide to trademark opposition covers the background.

Use Signa to find US applications similar to APPLE that are open for opposition. When does the window close for APPLE ADS?

search_trademarks filters on opposition status, get_trademark returns the record with its computed window, and get_opposition_rules supplies the rule behind it.

Signa data, queried 2026-10-13. Similar-name search for APPLE, US, open for opposition. Office data version dated 2026-09-28.

This is a snapshot from 2026-10-13, when the window had 16 days left. The US rule is a 30-day window starting the day after publication, under 15 U.S.C. § 1063(a), with extensions under 37 CFR § 2.102. Whether to oppose is a legal decision, and the date is the only part the data settles.

5. When is the next deadline on a trademark registration?

Use Signa to look up US registration 1811334. What is the next maintenance deadline?

A registration number in the search returns that record. get_trademark then returns the deadlines Signa computes for it, and get_deadline_rules gives the rule with its statutory sources.

Signa data, queried 2026-10-13. Filter: US registration 1811334. Office data version dated 2026-08-21.

The pattern is the US ten-year cycle: due at each tenth anniversary of registration, a filing window that opens 12 months earlier, and a 6-month grace period. The trademark renewal guide covers what the filing involves.

6. Which Nice classes does a product need?

Use Signa to suggest Nice classes for smart home cameras and a subscription app.

suggest_classifications takes a plain-language description and returns ranked classes with a confidence level and a reason.

Signa data, queried 2026-10-13. Input: "smart home cameras and a subscription app".

The third row is the useful one: it depends on a product decision, and the suggestion says so. The Nice classification reference lists all classes.

What a Claude trademark search still cannot do

As of 2026-10-13:

• Only the covered offices. 11 offices and 41.7 million records (Signa data, queried 2026-10-13, all live offices). Germany, Benelux, China, Japan, Korea and Mexico are planned, not live. A clean result says nothing about countries outside the list, which changes: ask Claude to list the offices Signa covers (list_offices is free).
• No unregistered marks. A common-law mark is a name that has rights through use in commerce without being registered, so it sits in no register. A common-law search is a separate job.
• Not a legal conclusion. A similarity tier is a ranking, not a finding of likelihood of confusion, and nothing here is a clearance opinion. Consult a trademark attorney for legal guidance specific to your situation.
• Claude can still misread the data. The tool returns records; the summary is Claude's. Check any number that matters against the office link included in the record.
• Freshness varies by office. Each office syncs daily or weekly. On 2026-10-13, IPOS (daily) had last synced on 2026-10-10 and CIPO (weekly) on 2026-10-07. Each record carries a source data date, which Signa's freshness docs define as when the office published that version of the data.
• Proceedings in five offices. Opposition and cancellation case data is available for the US, EUIPO, Canada, Australia and Singapore only (Signa data, queried 2026-10-13).
• No official fees. No tool returns office filing fees. Those come from each office's fee schedule.
• No watches from the connector. Signa's monitoring is live in beta, but a connector session can search and read only. Creating a watch needs an API key, which is a developer setup.
• Usage is metered. A search call costs 10 credits and a single record read costs 1, the same as the API. Office lookups are free and failed calls are not charged. The free plan can spend up to 5,000 credits per UTC day; plans are on signa.so/pricing.

For developers: connect Claude Code to Signa

Claude Code connects with one command:

claude mcp add --transport http signa https://api.signa.so/mcp

For scripts, CI or headless setups, Signa's docs use an API key as a bearer token in place of the browser login: add --header "Authorization: Bearer sig_YOUR_KEY" when adding the server. The APPLE ADS opposition window comes from this record, trimmed:

{
  "mark_text": "APPLE ADS",
  "office_code": "US",
  "application_number": "99947412",
  "publication_date": "2026-09-29",
  "derived": {
    "opposition_window": {
      "rule_id": "us_opposition",
      "window_opens": "2026-09-30",
      "window_closes": "2026-10-29",
      "office_time_zone": "America/New_York",
      "common_extension": { "days": 30, "as_of_right": true }
    }
  }
}

The full tool list and the scopes each tool needs are in the MCP tools reference. To write code against the same data, use the TypeScript SDK (@signa-so/sdk), the agent skill for coding agents (npx skills add signa-so/skills), or the OpenAPI spec.

Run your first Claude trademark search

Connect Signa from Claude's connector directory or with the custom connector steps, then ask about the name you care about most. Take what you find to a trademark attorney. A ChatGPT version of this guide will follow. Developers can start at docs.signa.so.