Accused of Trademark Infringement in Japan? What Overseas Sellers Should Check and Do

"A Japanese company says our brand name infringes their trademark." "Amazon Japan removed our listing after a trademark complaint." — For overseas sellers on Amazon, Rakuten or Yahoo! Shopping Japan, this message can arrive without warning.

In this article, Japanese Patent Attorney Toru Kano of BrandAgent explains what to check first, which defenses may be available under Japanese law, and how to respond without making things worse.

First, stay calm and do not reply in a hurry

A warning letter or platform complaint does not automatically mean you are infringing. Before you stop selling, apologize or sign anything, check the following three points with a Japanese patent attorney.

Three things to check

Does the other party's Japanese trademark registration really exist and is it still valid?
Is your name or logo really similar, and for similar goods or services?
Do you have a defense, such as non-use of their mark or a ground for invalidation?

Point 1: Check the other party's registration

Look up the registration number on J-PlatPat, the JPO's free database. A Japanese trademark right only exists once the mark is registered — a pending application cannot be enforced in the same way. Confirm:

that the mark is registered (not just applied for, refused or cancelled);
that the registration has not expired;
which goods and services it covers, and whether they overlap with what you sell.

Remember that trademark rights are territorial. A Japanese registration can be enforced against sales in Japan, including sales by overseas sellers to Japanese customers, but a Chinese or US registration of your own does not protect you in Japan.

Point 2: Check whether the marks are really similar

In Japan, similarity of marks is judged from three angles: appearance, pronunciation and meaning, considering how the marks are actually perceived in trade. The goods or services must also be identical or similar. Two marks that look alike on paper may be judged dissimilar, and vice versa — this is a judgment that needs professional experience.

Point 3: Check whether you have a defense

Possible defense	What it means
Not similar	The marks, or the goods/services, are not similar.
Non-use cancellation	If the owner has not used the mark in Japan for 3 or more consecutive years for the relevant goods/services, a non-use cancellation trial can be filed.
Invalidation trial	If the registration should never have been granted (for example, because it conflicts with an earlier mark), an invalidation trial may be possible. Some grounds have a time limit after registration.
Prior use right	Use that started in good faith before the other party filed may be protected, but the requirements are strict (your mark must already have been well known among consumers in Japan at that time).

If the complaint came through Amazon Japan or another marketplace

Marketplaces usually act on complaints quickly and may remove listings before any court decision. Keep a copy of the complaint and the complainant's contact details, check the cited registration as above, and respond through the marketplace's official procedure. If the complaint is unfounded, a clear explanation from a Japanese patent attorney is often the fastest way to have listings restored.

Above all, the best prevention is to register your own brand in Japan before you start selling. A registered owner is in a much stronger position when a competitor files a complaint.

Response steps

Step	What to do
1. Preserve evidence	Save the letter, e-mails or platform notices, and records of your own use (dates, listings, invoices).
2. Consult an attorney	Contact a Japanese patent attorney before replying.
3. Check the registration	Status, owner, goods/services and use of the cited mark.
4. Assess infringement	Similarity and available defenses.
5. Decide your response	Reply and keep selling, rebrand for Japan, negotiate a license or coexistence, or attack the registration.

What not to do

Do not admit infringement or promise to stop immediately before checking the facts.
Do not pay or accept demands in a panic.
Do not ignore the letter — silence can lead to a lawsuit or permanent removal of listings.

FAQ

Q. We did not know about their trademark. Are we still infringing?
A. Infringement can exist regardless of whether you knew about the registration. However, your good faith may matter when damages are discussed. Seek advice before responding.

Q. Our brand is registered in China. Doesn't that protect us?
A. No. Trademark rights are territorial. To be protected in Japan, you need a Japanese registration (directly or through a Madrid designation of Japan).

Q. Can we keep selling while we check?
A. It depends on the risk. If infringement is likely, continuing to sell after a warning can increase your exposure. Decide together with a Japanese attorney.

Q. Can BrandAgent communicate in Chinese?
A. Yes. We communicate in English and Chinese, and every case is handled personally by the patent attorney.

Planning to protect your brand in Japan?
Tell us your mark and your products — we will reply with the classes you need and a fixed quote, free of charge.

BrandAgent Patent Office (Kyoto, Japan)
Toru Kano, Japanese Patent Attorney

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