{"id":36,"date":"2026-03-12T20:17:21","date_gmt":"2026-03-12T11:17:21","guid":{"rendered":"https:\/\/brandagent.jp\/en_blog\/?p=36"},"modified":"2026-11-02T16:35:59","modified_gmt":"2026-11-02T07:35:59","slug":"japan_trademark_infringement","status":"publish","type":"post","link":"https:\/\/brandagent.jp\/en_blog\/japan_trademark_infringement\/","title":{"rendered":"Accused of Trademark Infringement in Japan? How to Respond to a Warning Letter or an Amazon\/Rakuten Complaint"},"content":{"rendered":"<p><span style=\"font-size: 120%;\">&#8220;We received a warning letter from a Japanese company saying our brand infringes their trademark.&#8221; &#8220;Our Amazon Japan listing was taken down after an IP complaint.&#8221; &#8220;Do we have to stop selling right away?&#8221;<\/span><\/p>\n<p><span style=\"font-size: 120%;\">Overseas sellers entering the Japanese market face these situations more and more often. In this article, Japanese Patent Attorney Toru Kano of BrandAgent explains what to do when you are told you infringe a Japanese trademark \u2014 what to check first, when it is not infringement, and the options you actually have.<\/span><\/p>\n<p><span style=\"font-size: 120%;\">*This article is general information, not legal advice on a specific case (last updated: October 2026).<\/span><\/p>\n<div class=\"st-mybox st-mybox-class\" style=\"margin: 18px 0; padding: 16px; border: 2px solid #e5e7eb; border-radius: 10px; background: #fafafa;\">\n<p><span style=\"font-size: 120%;\"><strong>What you will learn<\/strong><\/span><\/p>\n<ul style=\"margin: 10px 0 0 18px;\">\n<li><span style=\"font-size: 120%;\">The first things to do (and not do) after a warning letter or platform complaint<\/span><\/li>\n<li><span style=\"font-size: 120%;\">How infringement is decided under Japanese law<\/span><\/li>\n<li><span style=\"font-size: 120%;\">Cases where a warning does not mean infringement<\/span><\/li>\n<li><span style=\"font-size: 120%;\">Your practical options and what the other side can do<\/span><\/li>\n<li><span style=\"font-size: 120%;\">What to prepare now, and how a Japanese patent attorney can help<\/span><\/li>\n<\/ul>\n<\/div>\n<h2><span style=\"font-size: 120%;\">First steps: don&#8217;t admit, don&#8217;t ignore, don&#8217;t panic<\/span><\/h2>\n<p><span style=\"font-size: 120%;\">When a warning letter arrives, three reactions cause the most trouble:<\/span><\/p>\n<ul>\n<li><span style=\"font-size: 120%;\"><strong>Admitting infringement immediately<\/strong> \u2014 an apology or admission in writing can later be used against you, including in a damages claim.<\/span><\/li>\n<li><span style=\"font-size: 120%;\"><strong>Ignoring the letter<\/strong> \u2014 if the claim is valid, silence can lead to a lawsuit, an injunction or a larger damages claim.<\/span><\/li>\n<li><span style=\"font-size: 120%;\"><strong>Replying emotionally<\/strong> \u2014 an angry reply rarely helps and may close the door to a settlement.<\/span><\/li>\n<\/ul>\n<p><span style=\"font-size: 120%;\">The right first step is to <strong>check the facts calmly<\/strong>: what right is being asserted, whether it is valid, and whether your use actually falls within it. Note any deadline stated in the letter, but do not let it rush you into a reply you have not checked.<\/span><\/p>\n<h2><span style=\"font-size: 120%;\">Warning letters vs. Amazon Japan \/ Rakuten complaints<\/span><\/h2>\n<p><span style=\"font-size: 120%;\">For cross-border e-commerce sellers, the &#8220;warning&#8221; often does not come as a letter but as a notice from the platform: a listing is removed or your account receives an &#8220;intellectual property complaint&#8221; filed by the rights holder.<\/span><\/p>\n<div class=\"st-mybox  has-title st-mybox-class\" style=\"background:#ffebee;border-color:#ef9a9a;border-width:2px;border-radius:5px;margin: 25px 0 25px 0;\"><p class=\"st-mybox-title\" style=\"color:#ef5350;font-weight:bold;text-shadow: #fff 3px 0px 0px, #fff 2.83487px 0.981584px 0px, #fff 2.35766px 1.85511px 0px, #fff 1.62091px 2.52441px 0px, #fff 0.705713px 2.91581px 0px, #fff -0.287171px 2.98622px 0px, #fff -1.24844px 2.72789px 0px, #fff -2.07227px 2.16926px 0px, #fff -2.66798px 1.37182px 0px, #fff -2.96998px 0.42336px 0px, #fff -2.94502px -0.571704px 0px, #fff -2.59586px -1.50383px 0px, #fff -1.96093px -2.27041px 0px, #fff -1.11013px -2.78704px 0px, #fff -0.137119px -2.99686px 0px, #fff 0.850987px -2.87677px 0px, #fff 1.74541px -2.43999px 0px, #fff 2.44769px -1.73459px 0px, #fff 2.88051px -0.838246px 0px;\"><i class=\"fa fa-check-circle st-css-no\" aria-hidden=\"true\"><\/i>If you received a platform complaint<\/p><div class=\"st-in-mybox\">\n<ul>\n<li><span style=\"font-size: 120%;\">Note the complaint details: the complainant&#8217;s name, the trademark (and registration number, if given) and the listings concerned.<\/span><\/li>\n<li><span style=\"font-size: 120%;\">Check the cited registration in Japan&#8217;s official database (J-PlatPat): is it registered, who owns it, and for which goods?<\/span><\/li>\n<li><span style=\"font-size: 120%;\">Platforms do not judge infringement the way a court does. A complaint can be wrong \u2014 for example, when you sell genuine products, or when the registration covers different goods.<\/span><\/li>\n<li><span style=\"font-size: 120%;\">Repeated complaints can affect your seller account, so respond through the platform&#8217;s procedure (appeal, or asking the complainant to retract) rather than simply relisting.<\/span><\/li>\n<\/ul>\n<\/div><\/div>\n<p><span style=\"font-size: 120%;\">Whether it is a letter or a platform complaint, the legal question is the same: does your use fall within the scope of the other party&#8217;s Japanese trademark right?<\/span><\/p>\n<h2><span style=\"font-size: 120%;\">What decides infringement in Japan?<\/span><\/h2>\n<p><span style=\"font-size: 120%;\">In Japan, trademark rights are territorial and based on registration. As a rule, infringement requires <strong>both<\/strong> of the following:<\/span><\/p>\n<ul>\n<li><span style=\"font-size: 120%;\">Your mark is <strong>identical or similar<\/strong> to the registered mark, and<\/span><\/li>\n<li><span style=\"font-size: 120%;\">Your goods\/services are <strong>identical or similar<\/strong> to the designated goods\/services of the registration.<\/span><\/li>\n<\/ul>\n<p><span style=\"font-size: 120%;\">If either side is dissimilar, there is generally no infringement. Also note: a trademark you own in China, Korea, the US or elsewhere does not give you rights in Japan. What matters is the Japanese register.<\/span><\/p>\n<h2><span style=\"font-size: 120%;\">Three things to check first<\/span><\/h2>\n<div class=\"st-mybox  has-title st-mybox-class\" style=\"background:#f1f8e9;border-color:#a5d6a7;border-width:2px;border-radius:5px;margin: 25px 0 25px 0;\"><p class=\"st-mybox-title\" style=\"color:#4caf50;font-weight:bold;text-shadow: #fff 3px 0px 0px, #fff 2.83487px 0.981584px 0px, #fff 2.35766px 1.85511px 0px, #fff 1.62091px 2.52441px 0px, #fff 0.705713px 2.91581px 0px, #fff -0.287171px 2.98622px 0px, #fff -1.24844px 2.72789px 0px, #fff -2.07227px 2.16926px 0px, #fff -2.66798px 1.37182px 0px, #fff -2.96998px 0.42336px 0px, #fff -2.94502px -0.571704px 0px, #fff -2.59586px -1.50383px 0px, #fff -1.96093px -2.27041px 0px, #fff -1.11013px -2.78704px 0px, #fff -0.137119px -2.99686px 0px, #fff 0.850987px -2.87677px 0px, #fff 1.74541px -2.43999px 0px, #fff 2.44769px -1.73459px 0px, #fff 2.88051px -0.838246px 0px;\"><i class=\"fa fa-check-circle st-css-no\" aria-hidden=\"true\"><\/i>Checklist<\/p><div class=\"st-in-mybox\">\n<ul>\n<li><span style=\"font-size: 120%;\"><strong>1. The other party&#8217;s registration:<\/strong> Is it actually registered in Japan (not merely applied for)? Is it still in force? Who is the owner? What exactly does the mark look like?<\/span><\/li>\n<li><span style=\"font-size: 120%;\"><strong>2. The designated goods\/services:<\/strong> Which classes and goods does it cover? Are your products within them or similar to them?<\/span><\/li>\n<li><span style=\"font-size: 120%;\"><strong>3. How you use the mark:<\/strong> Is it your brand name on the product, packaging or listing title \u2014 or just a word in a product description?<\/span><\/li>\n<\/ul>\n<\/div><\/div>\n<p><span style=\"font-size: 120%;\">A pending application cannot be enforced as a trademark right yet (although the applicant may later claim compensation after registration in some cases). The registration number allows us to check all of this quickly.<\/span><\/p>\n<h2><span style=\"font-size: 120%;\">Should you stop using the mark immediately?<\/span><\/h2>\n<p><span style=\"font-size: 120%;\">It depends. If the other party&#8217;s registration is valid and your use clearly falls within it, continuing use increases your risk, and stopping (or pausing sales in Japan) while you negotiate may be wise. If there is a real argument for non-infringement, stopping immediately may cost you sales unnecessarily.<\/span><\/p>\n<p><span style=\"font-size: 120%;\">The decision should be based on the strength of the claim and the business impact \u2014 ideally after a Japanese patent attorney has reviewed the registration and your use.<\/span><\/p>\n<h2><span style=\"font-size: 120%;\">A warning does not always mean infringement<\/span><\/h2>\n<p><span style=\"font-size: 120%;\">Warning letters are sometimes sent even when the claim is weak. Common situations where there may be no infringement:<\/span><\/p>\n<ul>\n<li><span style=\"font-size: 120%;\">The marks look and sound different overall, or the goods are not similar.<\/span><\/li>\n<li><span style=\"font-size: 120%;\">You are reselling <strong>genuine products<\/strong> put on the market by the brand owner or with its consent (in general, reselling genuine goods is not infringement, although conditions apply, e.g. for parallel imports).<\/span><\/li>\n<li><span style=\"font-size: 120%;\">The word is used only to describe the product&#8217;s quality, ingredients, use or compatibility, not as a brand.<\/span><\/li>\n<li><span style=\"font-size: 120%;\">The registration may itself be invalid, or the mark has not been used in Japan for 3+ consecutive years and is open to non-use cancellation.<\/span><\/li>\n<\/ul>\n<h2><span style=\"font-size: 120%;\">Is it &#8220;use as a trademark&#8221;?<\/span><\/h2>\n<p><span style=\"font-size: 120%;\">Japanese law focuses on whether a word or logo functions as a brand \u2014 identifying who the goods come from. Using a registered word merely as a descriptive term (for example, &#8220;compatible with XX&#8221; or a common ingredient name) may not be trademark use.<\/span><\/p>\n<p><span style=\"font-size: 120%;\">However, e-commerce sellers should be careful: putting another company&#8217;s brand in your listing title or keywords to attract searches can be treated as trademark use and is also a frequent cause of platform complaints.<\/span><\/p>\n<h2><span style=\"font-size: 120%;\">Your practical options<\/span><\/h2>\n<table style=\"border-collapse: collapse; width: 100%;\" border=\"1\">\n<thead>\n<tr style=\"background-color: #f5f5f5;\">\n<th style=\"padding: 8px; text-align: left;\"><span style=\"font-size: 120%;\">Option<\/span><\/th>\n<th style=\"padding: 8px; text-align: left;\"><span style=\"font-size: 120%;\">When it fits<\/span><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"padding: 8px;\"><span style=\"font-size: 120%;\"><strong>Argue non-infringement<\/strong><\/span><\/td>\n<td style=\"padding: 8px;\"><span style=\"font-size: 120%;\">The marks or goods are not similar, or your use is not trademark use. Reply in writing with reasons.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 8px;\"><span style=\"font-size: 120%;\"><strong>Modify or limit your use<\/strong><\/span><\/td>\n<td style=\"padding: 8px;\"><span style=\"font-size: 120%;\">Changing the name, logo or the products sold under it can settle the matter at lower cost than a dispute.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 8px;\"><span style=\"font-size: 120%;\"><strong>Stop use and negotiate<\/strong><\/span><\/td>\n<td style=\"padding: 8px;\"><span style=\"font-size: 120%;\">The claim is strong. Negotiate a transition period, a license, or even purchase of the registration.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 8px;\"><span style=\"font-size: 120%;\"><strong>Challenge their registration<\/strong><\/span><\/td>\n<td style=\"padding: 8px;\"><span style=\"font-size: 120%;\">The registration has grounds for invalidity, or the mark has not been used in Japan for 3+ years (non-use cancellation trial).<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-size: 120%;\">These options can be combined \u2014 for example, filing a non-use cancellation trial while negotiating.<\/span><\/p>\n<h2><span style=\"font-size: 120%;\">What the rights holder can do<\/span><\/h2>\n<p><span style=\"font-size: 120%;\">If the matter is not settled, a Japanese trademark owner can seek:<\/span><\/p>\n<ul>\n<li><span style=\"font-size: 120%;\">An injunction (stopping sales, removal of infringing goods)<\/span><\/li>\n<li><span style=\"font-size: 120%;\">Damages<\/span><\/li>\n<li><span style=\"font-size: 120%;\">Return of unjust enrichment<\/span><\/li>\n<li><span style=\"font-size: 120%;\">Measures to restore business reputation<\/span><\/li>\n<\/ul>\n<p><span style=\"font-size: 120%;\">Intentional infringement can also carry criminal penalties, and customs can stop infringing goods at the border. This is another reason not to ignore a well-founded claim.<\/span><\/p>\n<h2><span style=\"font-size: 120%;\">What to prepare now<\/span><\/h2>\n<p><span style=\"font-size: 120%;\">Collect the following before replying \u2014 it is the basis for any argument:<\/span><\/p>\n<ul>\n<li><span style=\"font-size: 120%;\">When you started using the name (in Japan and in your home country)<\/span><\/li>\n<li><span style=\"font-size: 120%;\">Which products or services it is used for<\/span><\/li>\n<li><span style=\"font-size: 120%;\">How it is displayed: logo, text, product listings, descriptions<\/span><\/li>\n<li><span style=\"font-size: 120%;\">Evidence: product photos, packaging, ads, websites, sales records<\/span><\/li>\n<li><span style=\"font-size: 120%;\">Any earlier contact with the other party, and the source of your goods (invoices, if you sell genuine products)<\/span><\/li>\n<\/ul>\n<p><span style=\"font-size: 120%;\">Also check whether you have your own Japanese trademark application or registration. If you do not, consider filing one for your brand (after confirming it does not conflict) so the same problem does not recur.<\/span><\/p>\n<h2><span style=\"font-size: 120%;\">Why consult a Japanese patent attorney<\/span><\/h2>\n<p><span style=\"font-size: 120%;\">Similarity of marks and goods is judged under Japanese examination and court practice, which can differ from your home country. A Japanese patent attorney can assess the registration, estimate the risk, draft the reply, and \u2014 if needed \u2014 file an invalidation or non-use cancellation trial at the JPO. If you have no address in Japan, any JPO procedure must in any case be filed through a representative in Japan.<\/span><\/p>\n<p><span style=\"font-size: 120%;\">At BrandAgent, every case is handled personally by a licensed patent attorney, and we communicate in English and Chinese. Consultations and quotes are free.<\/span><\/p>\n<h2><span style=\"font-size: 120%;\">FAQ<\/span><\/h2>\n<ul>\n<li><span style=\"font-size: 120%;\"><strong>Q. Does a warning letter mean we definitely infringe?<\/strong><br \/>\nA. No. Infringement requires similar marks and similar goods\/services, and use as a trademark. Warnings are sometimes sent on weak grounds.<\/span><\/li>\n<li><span style=\"font-size: 120%;\"><strong>Q. Can we just ignore it?<\/strong><br \/>\nA. Not recommended. If the claim is valid, ignoring it can lead to a lawsuit or larger damages. Check the facts and reply in an appropriate way.<\/span><\/li>\n<li><span style=\"font-size: 120%;\"><strong>Q. Our Amazon Japan listing was removed. What should we do?<\/strong><br \/>\nA. Check the cited Japanese registration on J-PlatPat and compare it with your product and listing. If the complaint is unfounded (e.g. genuine goods, dissimilar goods), respond through the platform&#8217;s procedure or ask the complainant to retract.<\/span><\/li>\n<li><span style=\"font-size: 120%;\"><strong>Q. We own the trademark in China. Doesn&#8217;t that protect us in Japan?<\/strong><br \/>\nA. No. Trademark rights are territorial. Only a Japanese registration (or a Madrid registration designating Japan) gives rights in Japan.<\/span><\/li>\n<li><span style=\"font-size: 120%;\"><strong>Q. Do we have to stop selling immediately?<\/strong><br \/>\nA. It depends on the strength of the claim. Have the registration and your use reviewed first, then decide.<\/span><\/li>\n<\/ul>\n<h2><span style=\"font-size: 120%;\">Summary<\/span><\/h2>\n<div class=\"st-mybox  has-title st-mybox-class\" style=\"background:#f1f8e9;border-color:#a5d6a7;border-width:2px;border-radius:5px;margin: 25px 0 25px 0;\"><p class=\"st-mybox-title\" style=\"color:#4caf50;font-weight:bold;text-shadow: #fff 3px 0px 0px, #fff 2.83487px 0.981584px 0px, #fff 2.35766px 1.85511px 0px, #fff 1.62091px 2.52441px 0px, #fff 0.705713px 2.91581px 0px, #fff -0.287171px 2.98622px 0px, #fff -1.24844px 2.72789px 0px, #fff -2.07227px 2.16926px 0px, #fff -2.66798px 1.37182px 0px, #fff -2.96998px 0.42336px 0px, #fff -2.94502px -0.571704px 0px, #fff -2.59586px -1.50383px 0px, #fff -1.96093px -2.27041px 0px, #fff -1.11013px -2.78704px 0px, #fff -0.137119px -2.99686px 0px, #fff 0.850987px -2.87677px 0px, #fff 1.74541px -2.43999px 0px, #fff 2.44769px -1.73459px 0px, #fff 2.88051px -0.838246px 0px;\"><i class=\"fa fa-check-circle st-css-no\" aria-hidden=\"true\"><\/i>Key points<\/p><div class=\"st-in-mybox\">\n<ul>\n<li><span style=\"font-size: 120%;\">Don&#8217;t admit, ignore, or reply emotionally \u2014 check the facts first.<\/span><\/li>\n<li><span style=\"font-size: 120%;\">Infringement generally requires both a similar mark and similar goods\/services.<\/span><\/li>\n<li><span style=\"font-size: 120%;\">Check the other party&#8217;s Japanese registration, its goods, and how you use the mark.<\/span><\/li>\n<li><span style=\"font-size: 120%;\">Options: argue non-infringement, modify use, negotiate, or challenge their registration.<\/span><\/li>\n<li><span style=\"font-size: 120%;\">Protect your own brand in Japan with your own registration.<\/span><\/li>\n<\/ul>\n<\/div><\/div>\n<h2 id=\"related-articles\"><span style=\"font-size: 120%;\">Related articles<\/span><\/h2>\n<ul>\n<li><span style=\"font-size: 120%;\"><a href=\"https:\/\/brandagent.jp\/en_blog\/japan-trademark-infringement-warning-letter\/\">Accused of Trademark Infringement in Japan? What Overseas Sellers Should Check and Do<\/a><\/span><\/li>\n<li><span style=\"font-size: 120%;\"><a href=\"https:\/\/brandagent.jp\/en_blog\/japan-trademark-rights\/\">What Is a Trademark Right in Japan? When It Arises, Scope, Duration and Infringement<\/a><\/span><\/li>\n<li><span style=\"font-size: 120%;\"><a href=\"https:\/\/brandagent.jp\/en_blog\/amazon-japan-brand-registry-trademark\/\">Amazon Brand Registry in Japan: Getting the Japanese Trademark You Need<\/a><\/span><\/li>\n<li><span style=\"font-size: 120%;\"><a href=\"https:\/\/brandagent.jp\/en_blog\/japan-trademark-invalidation-trial\/\">Trademark Invalidation Trial in Japan: Grounds, Who Can File, and How It Differs from Opposition<\/a><\/span><\/li>\n<\/ul>\n<div style=\"background-color: #f0f7ff; border: 2px solid #0066cc; padding: 20px; margin: 24px 0; border-radius: 6px;\">\n<p><span style=\"font-size: 120%;\"><strong>Received a warning letter or a platform complaint in Japan?<\/strong><br \/>\nSend us the letter or complaint and the registration number \u2014 we will review it and reply with our view and a quote, free of charge.<\/span><\/p>\n<p><span style=\"font-size: 120%;\">BrandAgent Patent Office (Kyoto, Japan)<br \/>\nToru Kano, Japanese Patent Attorney<\/span><\/p>\n<p><a style=\"color: #0066cc; font-weight: bold;\" href=\"https:\/\/brandagent.jp\/en\/trademark_lp\/\" target=\"_blank\" rel=\"noopener\"><span style=\"font-size: 120%;\">Get a free quote for your Japanese trademark<\/span><\/a><\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Received a trademark warning letter or an Amazon Japan \/ Rakuten infringement complaint? A Japanese patent attorney explains what to check first, when it is (and isn&#8217;t) infringement, and your practical options.<\/p>\n","protected":false},"author":1,"featured_media":358,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"class_list":["post-36","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-trademark"],"_links":{"self":[{"href":"https:\/\/brandagent.jp\/en_blog\/wp-json\/wp\/v2\/posts\/36","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/brandagent.jp\/en_blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/brandagent.jp\/en_blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/brandagent.jp\/en_blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/brandagent.jp\/en_blog\/wp-json\/wp\/v2\/comments?post=36"}],"version-history":[{"count":3,"href":"https:\/\/brandagent.jp\/en_blog\/wp-json\/wp\/v2\/posts\/36\/revisions"}],"predecessor-version":[{"id":216,"href":"https:\/\/brandagent.jp\/en_blog\/wp-json\/wp\/v2\/posts\/36\/revisions\/216"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/brandagent.jp\/en_blog\/wp-json\/wp\/v2\/media\/358"}],"wp:attachment":[{"href":"https:\/\/brandagent.jp\/en_blog\/wp-json\/wp\/v2\/media?parent=36"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/brandagent.jp\/en_blog\/wp-json\/wp\/v2\/categories?post=36"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/brandagent.jp\/en_blog\/wp-json\/wp\/v2\/tags?post=36"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}