{"id":3030,"date":"2026-09-18T18:09:40","date_gmt":"2026-09-18T12:39:40","guid":{"rendered":"https:\/\/www.smsgatewaycenter.com\/blog\/?post_type=docs&#038;p=3030"},"modified":"2026-09-18T18:09:41","modified_gmt":"2026-09-18T12:39:41","password":"","slug":"why-was-my-dlt-header-deactivated-and-how-many-variables-can-a-template-have","status":"publish","type":"docs","link":"https:\/\/www.smsgatewaycenter.com\/blog\/kb\/why-was-my-dlt-header-deactivated-and-how-many-variables-can-a-template-have\/","title":{"rendered":"Why was my DLT header deactivated, and how many variables can a template have?"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">TRAI&#8217;s February 2025 amendment added rules on inactive headers and on how templates are built. Both can cause failures that look puzzling at first.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Headers unused for 90 days are deactivated<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If a header (sender ID) sends <strong>no messages for 90 days<\/strong>, it is deactivated automatically. Messages sent with it afterwards fail as an invalid or blocked sender.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>To reactivate:<\/strong> log in to your DLT portal and request reactivation of the header.<\/li>\n\n\n\n<li><strong>To prevent it:<\/strong> review your headers every quarter. Retire the ones you no longer need and keep the rest in use.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Limits on template variables<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>A template can normally have <strong>up to three variables<\/strong>. More are allowed only in special cases, with justification to the operator.<\/li>\n\n\n\n<li>At least <strong>30% of the template<\/strong> must be fixed text. A template made almost entirely of variables will be rejected.<\/li>\n\n\n\n<li>Each variable must use the correct tag, such as <code>{#numeric#}<\/code> or <code>{#url#}<\/code>. See <em>What are DLT variable tags, and which one should I use?<\/em><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">One template, one header<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A content template cannot be linked to more than one header. If you send the same text from two headers, register it once per header. Otherwise the message fails with a sender ID mismatch (<strong>SENDERID_MISMATCH<\/strong>).<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Quick checklist before registering a template<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The right category (see <em>Which category should I register my DLT template under?<\/em>)<\/li>\n\n\n\n<li>Mostly fixed text, with no more variables than you need<\/li>\n\n\n\n<li>Every link and callback number whitelisted<\/li>\n\n\n\n<li>Linked to the single header that will send it<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Official source:<\/strong> <a href=\"https:\/\/www.trai.gov.in\/sites\/default\/files\/2025-02\/Regulation_12022025.pdf\" target=\"_blank\" rel=\"noopener nofollow\">TCCCPR (Second Amendment) Regulations, 12 Feb 2025<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>TRAI&#8217;s February 2025 amendment added rules on inactive headers and on how templates are built. Both can cause failures that look puzzling at first. Headers unused for 90 days are deactivated If a header (sender ID) sends no messages for 90 days, it is deactivated automatically. Messages sent with it afterwards fail as an invalid [&hellip;]<\/p>\n","protected":false},"author":118,"featured_media":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"doc_category":[1328],"doc_tag":[],"class_list":["post-3030","docs","type-docs","status-publish","hentry","doc_category-dlt"],"year_month":"2026-09","word_count":249,"total_views":"2","reactions":{"happy":"0","normal":"0","sad":"0"},"author_info":{"name":"admin","author_nicename":"admin","author_url":"https:\/\/www.smsgatewaycenter.com\/blog\/author\/admin\/"},"doc_category_info":[{"term_name":"DLT","term_url":"https:\/\/www.smsgatewaycenter.com\/blog\/kb-cat\/dlt\/"}],"doc_tag_info":[],"_links":{"self":[{"href":"https:\/\/www.smsgatewaycenter.com\/blog\/wp-json\/wp\/v2\/docs\/3030","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.smsgatewaycenter.com\/blog\/wp-json\/wp\/v2\/docs"}],"about":[{"href":"https:\/\/www.smsgatewaycenter.com\/blog\/wp-json\/wp\/v2\/types\/docs"}],"author":[{"embeddable":true,"href":"https:\/\/www.smsgatewaycenter.com\/blog\/wp-json\/wp\/v2\/users\/118"}],"replies":[{"embeddable":true,"href":"https:\/\/www.smsgatewaycenter.com\/blog\/wp-json\/wp\/v2\/comments?post=3030"}],"version-history":[{"count":0,"href":"https:\/\/www.smsgatewaycenter.com\/blog\/wp-json\/wp\/v2\/docs\/3030\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.smsgatewaycenter.com\/blog\/wp-json\/wp\/v2\/media?parent=3030"}],"wp:term":[{"taxonomy":"doc_category","embeddable":true,"href":"https:\/\/www.smsgatewaycenter.com\/blog\/wp-json\/wp\/v2\/doc_category?post=3030"},{"taxonomy":"doc_tag","embeddable":true,"href":"https:\/\/www.smsgatewaycenter.com\/blog\/wp-json\/wp\/v2\/doc_tag?post=3030"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}