The USPTO’s Trademark Electronic Search System (TESS) is a free tool for searching federally registered and pending trademarks. It is not a comprehensive trademark clearance tool. Understanding what TESS misses, and the specific ways a TESS-only search can return misleading results, matters for anyone making business or filing decisions based on clearance research.

What TESS Searches (and What It Does Not)

TESS searches only federal trademark records: marks that have been filed with, registered by, or are pending before the United States Patent and Trademark Office. It does not search state trademark registrations, common law trademark uses, or business name registrations. A mark can be in active, protected use across the country, creating genuine infringement risk, without appearing in TESS at all.

A comprehensive trademark search answers three questions: Is the mark available under federal trademark law? Is it available under state trademark law in the relevant jurisdictions? Is it available under common law, meaning has someone established rights through use even without registration? TESS answers the first question only. Relying on a TESS-only search to clear a mark for use or filing leaves two of those three questions unanswered.

Boolean Search Errors That Produce Misleading Results

Even for the federal records TESS does cover, the system requires users to construct queries using Boolean logic and specific syntax. Errors in query construction are common and consequential, because a query that looks correct can silently exclude directly relevant marks.

Common errors that experienced searchers avoid, but that trip up occasional TESS users, include:

  • Missing truncation wildcards. Searching for APPLE without a wildcard returns only exact matches for “APPLE.” It excludes plural forms, possessives, compound marks (APPLEBERRY, APPLEWARE), and stylized variants. A search that appears clear can miss a directly conflicting registration that any professional searcher would flag.
  • Incorrect Boolean operator use. TESS uses AND, OR, and NOT, but the system’s operator precedence is not intuitive, and the default search mode differs from advanced search mode. A query intended to find marks in two related International Classes may return incomplete results if the operators are not structured correctly for the mode being used.
  • Wrong International Class codes. A trademark is registered in one or more of the Nice Classification system’s 45 International Classes, based on the specific goods or services covered. Searching only in Class 25 (clothing) when a conflicting mark may also be registered in Class 18 (leather goods) or Class 35 (retail services) can produce a false-clear result. Identifying the correct classes for a given mark is itself a judgment call that occasional users frequently get wrong.
  • Misreading live vs. dead mark status. TESS shows both live and dead marks. A mark marked as “dead” or abandoned is not necessarily available for use. If the owner used the mark continuously in commerce after abandoning the registration, common law rights may persist. TESS status codes do not resolve common law questions, and treating a dead federal registration as equivalent to a clear mark is an error professional searchers avoid by design.
  • Design code searches omitted. Word marks are only part of the trademark landscape. Marks that incorporate distinctive design elements are also registered and searchable, but only through design search codes that require a different search methodology entirely. A word-only TESS search leaves design mark conflicts unexamined.

TESS Is Being Replaced: New System, New Learning Curve

The USPTO has been transitioning from TESS to a new trademark search platform. For users who learned TESS’s specific interface, operator syntax, and search field structure, the transition introduces a period of additional uncertainty. Query logic that behaved predictably in TESS may produce different results in the replacement system until users have rebuilt their familiarity with the new platform’s behavior.

Why Professional Trademark Searches Use Clarivate Data Instead

Law firms and IP attorneys conducting clearance searches for clients typically do not use TESS as their primary search tool. Professional-grade trademark searches use Clarivate/Thomson Reuters trademark data, which provides more comprehensive federal and state coverage with more reliable search infrastructure than the USPTO’s public portal. According to Clarivate’s trademark screening platform, their database is the recognized industry standard for IP professionals conducting defensible clearance work.

Creative Trademark Services has used Clarivate/Thomson Reuters data for all federal and state trademark searches since 1997. A full comprehensive search, covering federal records, all 50 state trademark databases, and common law use research, costs $425. The same Clarivate data ordered directly through an institutional subscription costs $1,000 or more per search.

For a detailed breakdown of what a TESS search covers compared to a professional search, and why the differences matter for attorneys advising clients on trademark availability, see our dedicated comparison: TESS vs. a Professional Trademark Search: Why One of These Can Get You Sued.

To order a comprehensive professional search, view our services here.