Patent Translation Requirements for Filing in China
February 19, 2026
What You Must Translate, When to File, and How to Avoid Costly Rejection
Under the rules of the China National Intellectual Property Administration (CNIPA), all patent documents must be filed in Simplified Chinese. If your translation narrows claim scope, introduces ambiguity, or mistranslates technical terminology, you may permanently lose protection—even if your original English application was flawless.
This guide explains the exact patent translation requirements for filing in China, including:
- Mandatory language rules
- PCT national phase translation deadlines
- Required documents
- Formatting standards
- Common rejection risks
- Best practices for protecting claim scope
Whether you’re filing a direct Chinese patent application or entering via the PCT route, this article will help you avoid preventable mistakes.
Filing in China? Then Chinese Is Not Optional.
China does not accept patents filed in English for substantive examination. The official filing language is Simplified Chinese.
What this means for applicants:
- All patent documents must be submitted in Chinese.
- The Chinese version becomes the legally binding text.
- In case of discrepancies, Chinese courts and examiners rely on the Chinese version—not the original.
This rule applies under the Patent Law of the People’s Republic of China.
Critical implication:
If your translation alters the meaning of a claim—even unintentionally—you cannot later rely on the English version to fix it.
What Exactly Must Be Translated? (Everything That Defines Scope)
When filing in China, the following patent documents must be translated into Chinese:
Patent Specification
This includes:
- Title of the invention
- Abstract
- Technical field
- Background art
- Summary
- Detailed description
- Claims
Why it matters:
The claims define the legal scope of protection. Even subtle wording shifts can:
- Narrow protection
- Create enforceability issues
- Trigger rejection during examination
Claims (The Most Sensitive Section)
Claims require:
- Terminology consistency
- Logical dependency clarity
- Accurate technical meaning
- Proper numbering structure
CNIPA examiners strictly review claim clarity and support in the description.
A Practical Guide to Regulatory Legal Translation for Multinational Companies
Drawings & Reference Numerals
- Figure descriptions must be translated.
- Reference numbers must remain consistent.
- Technical labels must align with description terminology.
Inconsistent terminology between drawings and claims often leads to office actions.
Sequence Listings (Biotech & Pharma)
For biotechnology applications:
- Sequence listings must comply with CNIPA formatting rules.
- Amino acid and nucleotide terminology must follow international standards.
Improper formatting may delay acceptance.
Priority Documents (If Required)
In some cases, priority documents must be translated into Chinese upon request.
Failure to submit within the deadline may result in loss of priority rights.
Entering China via PCT? Here’s the Translation Deadline You Cannot Miss.
If you filed through the Patent Cooperation Treaty (PCT), you must enter the Chinese national phase on time.
The World Intellectual Property Organization administers the international system.
Deadline for China National Phase Entry:
- 30 months from the priority date
By this deadline, you must submit:
- Chinese translation of the international application
- Translated claims (including amendments)
- Abstract
- Drawings (if text present)
What happens if you miss the translation deadline?
- Application deemed withdrawn
- Rights permanently lost in China
Restoration is very unlikely.
The Chinese Translation Becomes the Legal Authority
Here’s what many applicants misunderstand:
Once filed, the Chinese translation becomes the controlling legal document.
If the translation:
- Narrows a claim term
- Omits an embodiment
- Uses inconsistent terminology
You may not be able to broaden it later.
Chinese patent law prohibits adding “new matter” after filing. This means:
You cannot correct a translation if it expands beyond what was originally disclosed.
CNIPA Formatting & Terminology Standards (Details Matter More Than You Think)
CNIPA enforces strict formatting and terminology consistency rules.
Key technical requirements:
- Use of standardized Chinese technical terms
- Consistent translation of identical terms throughout
- Proper units of measurement (SI system)
- Correct chemical nomenclature
- Structured claim dependency formatting
Example of terminology risk:
| English Term | Incorrect Chinese Translation | Risk |
|---|---|---|
| “Comprising” | Translated as equivalent to “consisting of” | Narrows claim scope |
| “Substantially” | Omitted entirely | Alters interpretation |
| “Configured to” | Translated ambiguously | Creates clarity objection |
Small wording errors can significantly alter enforceability.
Common Patent Translation Mistakes That Trigger Rejection
Why machine translation is risky:
Patent language is legally precise. AI translation tools:
- Do not understand claim dependency logic
- Cannot interpret legal drafting nuance
- Often mistranslates transitional phrases
A single mistranslated word may invalidate protection.
Can You Correct Translation Errors After Filing?
Yes—but only within limits.
You may:
- Correct obvious clerical errors
- Amend translation errors that do not add new matter
You may NOT:
- Expand claim scope beyond the original disclosure
- Introduce new technical features
- Add previously omitted embodiments
If the translation narrows the claim scope at filing, that narrowing may become permanent.
Do You Need a Certified Patent Translator in China?
CNIPA does not explicitly require notarized translation in most cases.
However:
- Patent translation requires both linguistic and technical expertise.
- Errors carry long-term enforcement risk.
Best practice:
Use:
- Patent-specialized translators
- Subject-matter experts (engineering, biotech, pharma)
- Legal reviewers familiar with Chinese patent prosecution
Risk Comparison
| Option | Risk Level | Suitability |
|---|---|---|
| General translator | High | Not recommended |
| Machine translation | Very High | Dangerous for claims |
| Patent-specialized linguist | Low | Recommended |
| Patent attorney review + translator | Lowest | Ideal for high-value filings |
Direct Filing vs PCT Entry: Translation Comparison
| Filing Route | Translation Required | Deadline |
|---|---|---|
| Direct China filing | Full Chinese translation at filing | Immediate |
| PCT national phase | Chinese translation by 30 months | Strict deadline |
Best Practices to Protect Claim Scope in China
If your patent matters commercially, treat translation as a legal strategy—not clerical work.
Follow these practices:
- Create a bilingual terminology glossary
- Maintain strict claim term consistency
- Use subject-matter expert translators
- Conduct a legal review before filing
- Compare the final Chinese claims against the English original
- Avoid last-minute rush translation
Advanced tip:
Perform a back-translation audit:
- Translate English → Chinese
- Independently translate Chinese → English
- Compare for scope shifts
This identifies subtle narrowing issues.
Final Takeaway: Translation Is a Legal Strategy
Patent translation for China is not administrative paperwork. It is:
- A legal risk management process
- A claim scope preservation strategy
- A compliance requirement under Chinese patent law
Work with qualified professionals. Protect your terminology. Review every claim carefully.
Because once your Chinese patent is granted, the words you filed are the rights you own.
Ensure Your Chinese Patent Translation Is Perfect
Learn how patent translation preserves claim scope and compliance with CNIPA. Protect your invention across borders.