{"id":718502,"date":"2026-03-24T01:05:11","date_gmt":"2026-03-23T22:05:11","guid":{"rendered":"https:\/\/buradabiliyorum.com\/en\/google-ads-api-to-block-duplicate-lookalike-user-lists\/"},"modified":"2026-03-24T01:05:11","modified_gmt":"2026-03-23T22:05:11","slug":"google-ads-api-to-block-duplicate-lookalike-user-lists","status":"publish","type":"post","link":"https:\/\/buradabiliyorum.com\/en\/google-ads-api-to-block-duplicate-lookalike-user-lists\/","title":{"rendered":"Google Ads API to block duplicate Lookalike user lists"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_88 counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<label for=\"ez-toc-cssicon-toggle-item-6acd751b59eb8\" class=\"ez-toc-cssicon-toggle-label\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #dd3333;color:#dd3333\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #dd3333;color:#dd3333\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/label><input type=\"checkbox\"  id=\"ez-toc-cssicon-toggle-item-6acd751b59eb8\" checked aria-label=\"Toggle\" \/><nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/buradabiliyorum.com\/en\/google-ads-api-to-block-duplicate-lookalike-user-lists\/#Google_will_soon_block_the_creation_of_duplicate_Lookalike_user_lists_in_the_Google_Ads_API_returning_an_error_code_for_any_violations\" >Google will soon block the creation of duplicate Lookalike user lists in the Google Ads API, returning an error code for any violations.<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"subhead\" itemprop=\"alternativeHeadline\"><span class=\"ez-toc-section\" id=\"Google_will_soon_block_the_creation_of_duplicate_Lookalike_user_lists_in_the_Google_Ads_API_returning_an_error_code_for_any_violations\"><\/span>Google will soon block the creation of duplicate Lookalike user lists in the Google Ads API, returning an error code for any violations.<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><\/p>\n<div class=\"bialty-container\">\n<p>A quiet but important change is coming to the Google Ads API that will affect how advertisers and developers create Lookalike user lists, especially for Demand Gen campaigns.<\/p>\n<p><strong>What\u2019s changing.<\/strong> Google will enforce a uniqueness check on Lookalike user lists, blocking duplicate lists with the same seed lists, expansion level, and country targeting. Attempts to create a duplicate will return an API error after April 30.<\/p>\n<p><strong>Why we care.<\/strong> If you use automated <a href=\"https:\/\/buradabiliyorum.com\/en\/category\/download-scripts-themes-apps\/\" data-internallinksmanager029f6b8e52c=\"9\" title=\"Download Scripts &amp; Themes &amp; Apps\" target=\"_blank\" rel=\"noopener\">script<\/a>s or third-party tools to generate audience lists, an unhandled error could quietly break your campaign workflows if you don\u2019t update integrations in time.<\/p>\n<p><strong>What you need to do.<\/strong><\/p>\n<ul class=\"wp-block-list\">\n<li>Audit existing Lookalike lists and reuse ones that already match your intended configuration rather than creating new ones<\/li>\n<li>Update your API error handling to catch the new <code>DUPLICATE_LOOKALIKE<\/code> error code in v24 and above, or <code>RESOURCE_ALREADY_EXISTS<\/code> in earlier versions<\/li>\n<\/ul>\n<p><strong>Bottom line.<\/strong> This is a housekeeping change to keep Google\u2019s systems stable, but the April 30 deadline is firm. If you manage campaigns programmatically, treat this as a technical to-do before the end of April.<\/p>\n<p><strong>Google\u2019s announcement.<\/strong> <a rel=\"nofollow\" target=\"_blank\" href=\"http:\/\/ads-developers.googleblog.com\/2026\/03\/upcoming-changes-to-lookalike-user.html\">Upcoming changes to Lookalike user lists in the Google Ads API, starting April 30, 2026<\/a><\/p>\n<\/div>\n<blockquote><p><strong><span style=\"color: #ff6600;\">If you liked the article, do not forget to share it with your friends. Follow us on\u00a0<span style=\"color: #ff0000;\"><a style=\"color: #ff0000;\" href=\"https:\/\/news.google.com\/publications\/CAAqBwgKMN63nwsw68G3Aw\" target=\"_blank\" rel=\"nofollow noopener noreferrer\">Google News<\/a><\/span>\u00a0too, click on the star and choose us from your favorites.<\/span><\/strong><\/p><\/blockquote>\n<blockquote>\n<p style=\"text-align: center;\"><strong>If you want to read more like this article, you can visit our <span style=\"color: #ff9900;\"><a style=\"color: #ff9900;\" href=\"https:\/\/buradabiliyorum.com\/en\/category\/technology\/\" target=\"_blank\" >Technology<\/a><\/span> category.<\/strong><\/p>\n<\/blockquote>\n<p><span style=\"color: black;\"><a style=\"color: #ff9900;\" href=\"https:\/\/searchengineland.com\/google-is-blocking-duplicate-lookalike-audience-lists-472239\" target=\"_blank\" >Source<\/a><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Google will soon block the creation of duplicate Lookalike user lists in the Google Ads API, returning an error code for any violations. A quiet but important change is coming to the Google Ads API that will affect how advertisers and developers create Lookalike user lists, especially for Demand Gen campaigns. What\u2019s changing. Google will&#8230;<\/p>\n","protected":false},"author":1,"featured_media":718503,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"https:\/\/searchengineland.com\/wp-content\/seloads\/2026\/02\/In-Google-Ads-automation-everything-is-a-signal-in-2026.jpg","fifu_image_alt":"","footnotes":""},"categories":[18],"tags":[],"class_list":["post-718502","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-technology"],"_links":{"self":[{"href":"https:\/\/buradabiliyorum.com\/en\/wp-json\/wp\/v2\/posts\/718502","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/buradabiliyorum.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/buradabiliyorum.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/buradabiliyorum.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/buradabiliyorum.com\/en\/wp-json\/wp\/v2\/comments?post=718502"}],"version-history":[{"count":0,"href":"https:\/\/buradabiliyorum.com\/en\/wp-json\/wp\/v2\/posts\/718502\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/buradabiliyorum.com\/en\/wp-json\/wp\/v2\/media\/718503"}],"wp:attachment":[{"href":"https:\/\/buradabiliyorum.com\/en\/wp-json\/wp\/v2\/media?parent=718502"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/buradabiliyorum.com\/en\/wp-json\/wp\/v2\/categories?post=718502"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/buradabiliyorum.com\/en\/wp-json\/wp\/v2\/tags?post=718502"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}