The prior-art documents were already in the case file. An expert had discussed them. Yet late translations left a patent challenger unable to rely on essential material supporting its attack.
For companies preparing international patent disputes in 2026, Spain’s Supreme Court judgment No. 1445/2023, delivered on 20 October 2023, remains a concrete warning about evidence preparation. The issue was not whether a translator could eventually produce an accurate document. It was whether the necessary translations had arrived at the procedural stage when they belonged.
A strong technical argument can lose its foundation when the documents supporting it are not properly presented.
The documents arrived before their translations ⚖️
The litigation concerned a tricycle patent. The defendant counterclaimed for invalidity, relying on an expert report that discussed four earlier patents. Three references were foreign-language documents: two French patents and one German patent.
The originals accompanied the report, which contained partial translations. Complete translations were offered at the preliminary hearing, after the patent owner had answered the counterclaim and raised the omission.
The Supreme Court upheld their exclusion as late. These references were essential to the inventive-step challenge, and their relevance existed when the counterclaim was filed. It had not arisen because of the opponent’s response. The attempted introduction on appeal did not cure the problem.
The court’s reasoning concerned the evidence underlying the invalidity argument. The judgment also addressed infringement separately; the whole dispute should not be reduced to a translation deadline. Iberley
The distinction matters commercially. Finding useful prior art and presenting usable evidence are separate tasks, with separate opportunities for failure.
Why an expert’s explanation does not replace the underlying evidence
An expert report explains what technical material means and why it matters. A translation makes the underlying foreign-language material accessible for examination.
Those functions overlap, but they are not identical.
An expert may translate the sentences supporting a particular conclusion while leaving surrounding passages untranslated. The opposing expert may need those surrounding passages to assess whether the conclusion is justified. A definition, alternative embodiment, or limitation elsewhere in the document may change the analysis.
Consider a hypothetical mechanical patent dispute. An expert quotes a passage describing a steering connection. Elsewhere, the same publication explains that the connection operates only in a specific configuration. Translating the quotation alone could leave that qualification outside the reader’s view.
This is not a description of an additional finding in the Spanish case. It illustrates why selected excerpts and a complete evidentiary document serve different purposes.
The translation should allow the technical argument to be tested, including by someone who disagrees with it.
The procedural rule was about more than convenience
Article 144 of Spain’s Civil Procedure Act requires a translation to accompany a document written in a language other than Spanish or, where applicable, the relevant regional official language. Article 265 addresses the submission of documents supporting the parties’ positions with their pleadings, while allowing specified exceptions.
The framework does not mean that every translation must initially be sworn or official. Article 144 permits a privately prepared translation and provides a mechanism for challenging its accuracy. Timing, completeness, and the form of translation are distinct questions. boe.es
For an international business, the practical instruction is therefore more precise than “order certified translations.”
Ask local counsel which documents must be translated, how much must be translated, what form is acceptable, and when each translation must be filed. Then give the language team enough time to meet those requirements.
Paying for a more formal translation does not, by itself, resolve a missed procedural deadline.
The dangerous gap between “located” and “ready” 📂
Patent evidence often passes through several people before reaching counsel. A researcher identifies a publication, an engineer evaluates it, an expert incorporates it into a report, and a litigation team assembles the exhibits.
Each handover can create the impression that someone else has handled the language requirement.
| Status reported internally | What it actually establishes | What may still be missing |
|---|---|---|
| “Prior art located” | A candidate document has been found | Correct publication and complete source |
| “Reviewed by the engineer” | Its technical relevance has been considered | Translation suitable for the intended use |
| “Included in the expert report” | The expert has referred to it | Required translation of the underlying exhibit |
| “Translation ordered” | Work has been commissioned | Review, approval, and delivery |
| “Translation delivered” | A language file is available | Counsel’s acceptance and actual filing |
The final row deserves attention. A translation sitting in an email inbox is not necessarily part of the filed evidence.
A litigation schedule should identify both delivery to counsel and submission to the court. Treating them as one event hides the time needed for exhibit numbering, pagination, review, and corrections.
A rushed translation can introduce a second problem 🔍
Meeting the deadline does not remove the need for accuracy.
Patent disputes frequently depend on relationships that appear minor in ordinary business writing: whether two elements are connected directly, whether a step is mandatory, or whether a feature belongs to one embodiment rather than every implementation.
A translation prepared under severe time pressure may preserve all the technical nouns while changing those relationships.
Three illustrative checks show what substantive review should cover:
Component identity.
If the source distinguishes a retaining ring from a locking ring, the translation should not merge them simply because their functions appear similar.
Operating sequence.
If a release occurs after a latch disengages, the wording should preserve that order. Reversing the sequence can describe a different mechanism.
Reference alignment.
A translated paragraph must still point to the correct figure and component number. A correct sentence paired with the wrong drawing can mislead the reader just as effectively as a mistranslated sentence.
These are general review examples, not claims about defects found in the Spanish proceedings.
Korean-language work requires its own assignment
The Spanish ruling does not establish Korean procedural law. Nor does a Korean translation satisfy a Spanish court’s language requirements.
Its operational lesson is nevertheless relevant to overseas companies working with Korean engineers, subsidiaries, manufacturers, or patent counsel: define the purpose of each language version early.
A Korean version prepared for internal technical assessment may help a research team understand foreign prior art. A document intended for submission in Korean proceedings requires a separate brief based on the applicable procedure and counsel’s instructions.
The distinction should be visible in the project records. Internal summaries, selected translations, and complete exhibit translations should not circulate under indistinguishable filenames.
For Korean patent translation, source control is equally important. The team should identify the exact publication, confirm that all pages are available, and retain stable references between the source and translated text. A related patent-family document may be helpful background, but it should not silently replace the document actually cited.
Build the translation deadline backward from filing ⏱️
The court’s filing date is the last point in a sequence of dependent tasks. It should not become the translator’s delivery date by default.
Start with counsel’s submission requirements. Allow time before that for legal review and exhibit preparation. Before legal review, reserve time for technical questions and translation quality checks.
A practical commissioning brief should establish:
- The exact documents and versions covered by the assignment.
- Whether full translations or defined extracts are required.
- The target language and any procedural formalities confirmed by counsel.
- The terminology and reference conventions used in the expert report.
- The person authorized to resolve source ambiguities.
- Separate dates for draft review, final delivery, and filing.
If the expert’s references change, the translation scope must be updated immediately. Adding a document to a report without adding it to the translation schedule creates an avoidable mismatch.
Give counsel a usable evidence package
Our Korean-language patent support can be organized around complete specifications, selected technical evidence, and review of existing Korean translations. The assignment should preserve the distinction between the source text, the expert’s analysis, and any translator queries.
For a document-heavy dispute, an exhibit register can identify the source filename, publication number, translation status, reviewer, and approved delivery version. Unresolved issues should remain visible until the responsible person addresses them.
Before the evidence package leaves the team, compare the expert report’s references with the translated exhibits one by one. Every cited document should have a confirmed status. Every missing page, untranslated section, or unresolved qualification should have a named owner and a decision from counsel.
Legal reference points: Supreme Court judgment No. 1445/2023, 20 October 2023, ECLI:ES:TS:2023:4412; and Articles 144 and 265 of Spain’s Civil Procedure Act. The official state gazette provides the legislation and a judicial-reference entry linking to the decision (source: https://www.boe.es).