Suing for Patent Infringement in China? Expect an Invalidation Request: Stays, Timing and Outcomes

The same patent can win an infringement case in one forum and be found invalid in another. That has just happened in Europe: DivX won an injunction against Netflix at the Unified Patent Court in September, and in October an EPO Opposition Division announced the revocation of the same patent (news). China also runs two tracks. Courts decide infringement; whether the patent is valid is decided by the China National Intellectual Property Administration (CNIPA) in invalidation proceedings. If you sue for patent infringement in China, expect the defendant to file an invalidation request. What follows is general guidance based on the Patent Law and the Supreme People's Court's Provisions on Patent Dispute Cases (amended 2020); individual cases need professional advice.

Two tracks: courts for infringement, CNIPA for validity

• Infringement action: the patentee sues in court, which decides whether the accused product or process falls within the claims and what damages to award. The court does not itself declare the patent invalid.
• Invalidation request: under Article 45 of the Patent Law, anyone may ask CNIPA to declare a patent invalid at any time after grant. Under Article 46, a party that disagrees with the decision may sue in court within three months of receiving it.

The two tracks move at their own speed, and their outcomes need not line up. Defendants usually answer the claim and attack the patent at the same time.

Will the court stay the infringement case?

It depends on the type of patent and when the invalidation request is filed:

1. Utility model or design patent, request filed within the defence period: under Article 5 of the Provisions, the court should in principle stay the case. It may decline to do so in four situations, including where the search report or patent evaluation report produced by the plaintiff found no ground for invalidity, where the defendant's evidence shows it used publicly known technology, or where the invalidation request is clearly unsupported.
2. Utility model or design patent, request filed after the defence period: under Article 6, the court should not stay the case unless it finds a stay necessary.
3. Invention patent, or a utility model or design already upheld in invalidation: under Article 7, the court may decline to stay the case even if the request is filed within the defence period. Invention patents have been through substantive examination, and in practice courts usually keep going.

The defence period is normally 15 days, or 30 days for a defendant with no domicile in China. For utility model and design patents, getting a patent evaluation report before suing is the usual way to avoid a stay; under Article 4 the court may also ask the plaintiff to produce one, and if the plaintiff refuses without good reason, the court may stay the case or let the plaintiff bear the adverse consequences.

What a patentee can do during a stay

Under Article 8, when a court stays the case, the patentee may ask it to order the defendant to stop the acts concerned or take other measures, and must provide security. If the request meets the legal conditions, the court can rule on it at the same time as the stay. A stay does not have to mean the infringement carries on.

If the patent is declared invalid

• The infringement case can be dismissed: under Article 2 of the Supreme People's Court's second Interpretation on patent infringement cases, if the asserted claims are declared invalid, the court may dismiss the action based on those claims. If the invalidation decision is later set aside by an effective administrative judgment, the patentee can sue again.
• Invalid from the start, but no reopening of settled matters: under Article 47 of the Patent Law, an invalidated patent is deemed never to have existed. As a rule, though, the decision does not affect infringement judgments already enforced, administrative rulings on infringement already performed or enforced, or licence and assignment contracts already performed, unless the patentee acted in bad faith.
• Not all or nothing: in invalidation proceedings, the owner of an invention or utility model patent may amend the claims without broadening them, but only by deleting claims or technical solutions, narrowing a claim with features from other claims, or correcting obvious errors. The patent may survive in narrower form, and the infringement case then continues on the surviving claims. Design drawings, photographs and the brief description cannot be amended.

Practical points for foreign patentees and defendants

1. Test validity before you sue: run an invalidity search on the prior art most likely to be cited, and for utility models and designs obtain an evaluation report. Sue on your strongest claims, not your broadest.
2. If you are sued, watch the defence period: file any invalidation request within it and tell the court once CNIPA has accepted it. A thinly supported request will not earn a stay.
3. Keep one position across both tracks: how a patentee reads its claims to save them in invalidation can later be used to limit their scope in the infringement case. One team should run both.
4. Check whether a result is final: invalidation decisions can be appealed to court and infringement judgments can be appealed too.

If you have not yet protected your invention in China, start with do you need a Chinese patent if you already have a US patent?

Frequently asked questions

Does an invalidation request automatically stop the infringement case? No. For invention patents the court may carry on. For utility models and designs, a request filed within the defence period normally leads to a stay, with exceptions.

Who can file an invalidation request? Anyone, not only the defendant. Competitors who expect to be sued often file first.

If damages were paid before the patent was invalidated, can the defendant get them back? Generally not, once the judgment has been enforced. The exceptions are bad faith by the patentee and cases where keeping the money would be clearly unfair.

J&C Intellectual Property Agency, founded in 2008, is a CNIPA-recorded trademark agency and a member of the China Trademark Association. We handle trademark filings and customs recordals in China for foreign brands; see our trademark registration service.