{"id":58,"date":"2026-04-19T19:06:18","date_gmt":"2026-04-19T18:06:18","guid":{"rendered":"http:\/\/sadiqur.xyz\/glazing\/index.php\/fensa-certass-trustmark\/"},"modified":"2026-04-20T00:15:44","modified_gmt":"2026-04-19T23:15:44","slug":"fensa-certass-trustmark","status":"publish","type":"post","link":"http:\/\/sadiqur.xyz\/glazing\/index.php\/fensa-certass-trustmark\/","title":{"rendered":"FENSA vs Certass vs Trustmark Explained"},"content":{"rendered":"\n<p class=\"has-text-color\" style=\"color:#64748B;font-size:0.95rem\">\ud83d\udcc5 Updated April 2026 \u00b7 \u23f1 Full guide in progress \u00b7 \u270d\ufe0f Findfitter Team<\/p>\n\n\n\n<p>Three UK schemes certify replacement window installers: <strong>FENSA<\/strong>, <strong>Certass<\/strong>, and <strong>Trustmark<\/strong>. They sound interchangeable \u2014 they&#8217;re not. Here&#8217;s the short version while our full guide is being finalised.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What they have in common<\/h2>\n\n\n<p>All three are Competent Persons Schemes authorised by the UK government. An installer registered with any of them is legally allowed to self-certify that their work meets building regulations \u2014 saving you the cost and delay of a local council inspection. All three provide insurance-backed warranties so your install is protected even if the installer goes out of business.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">FENSA<\/h2>\n\n\n<p>The largest scheme. Operated by the Glass and Glazing Federation. Most UK installers are FENSA registered. If you&#8217;re buying replacement windows or doors, FENSA is the default \u2014 you want your installer on this register.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Certass<\/h2>\n\n\n<p>The second-largest scheme \u2014 similar scope to FENSA. Equally valid. Some smaller installers prefer Certass due to lower membership fees.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Trustmark<\/h2>\n\n\n<p>Broader government-endorsed quality scheme covering multiple trades (not just glazing). If a window installer is Trustmark registered, they&#8217;ve been vetted on workmanship, customer service, and trading practices \u2014 but not necessarily on building regulation compliance for windows specifically. Best: an installer with both Trustmark <em>and<\/em> FENSA or Certass.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Verifying an installer&#8217;s registration<\/h2>\n\n\n<ul class=\"wp-block-list\">\n<li>FENSA: <a href=\"https:\/\/www.fensa.org.uk\/find-an-installer\" target=\"_blank\" rel=\"noopener\">fensa.org.uk<\/a><\/li>\n<li>Certass: <a href=\"https:\/\/www.certass.co.uk\" target=\"_blank\" rel=\"noopener\">certass.co.uk<\/a><\/li>\n<li>Trustmark: <a href=\"https:\/\/www.trustmark.org.uk\" target=\"_blank\" rel=\"noopener\">trustmark.org.uk<\/a><\/li>\n<\/ul>\n\n\n\n<p>Any fitter claiming certification that doesn&#8217;t appear on these public databases is lying. Walk away.<\/p>\n\n\n\n<p><em>Our full side-by-side comparison guide (coverage, fees, dispute resolution, pros\/cons of each) is being finalised. In the meantime, you can get quotes from pre-vetted installers who carry at least one of these certifications.<\/em><\/p>\n\n\n\t<div class=\"ff-city-cta\">\n\t\t<h3>Get quotes from FENSA-registered installers<\/h3>\n\t\t<p>Enter your postcode \u2014 we will match you with 4 vetted UK installers for a free, no-obligation comparison.<\/p>\n\t\t<form action=\"http:\/\/sadiqur.xyz\/glazing\/index.php\/quote\/\" method=\"GET\" class=\"ff-city-cta-form\">\n\t\t\t<label for=\"pc-AtcvDj\" class=\"screen-reader-text\">Enter your postcode<\/label>\n\t\t\t<input type=\"text\" id=\"pc-AtcvDj\" name=\"postcode\" placeholder=\"e.g. M1 2AB\" required autocomplete=\"postal-code\">\n\t\t\t<button type=\"submit\">Get My Free Quotes \u2192<\/button>\n\t\t<\/form>\n\t\t<div class=\"ff-city-cta-trust\">\n\t\t\t<span>\u2713 Free &amp; no obligation<\/span>\n\t\t\t<span>\u2713 FENSA-registered fitters only<\/span>\n\t\t\t<span>\u2713 2-minute form<\/span>\n\t\t<\/div>\n\t<\/div>\n\t\n\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\" style=\"margin-top:48px;margin-bottom:24px\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Sources &amp; references<\/h3>\n\n\n\n<p class=\"has-text-color\" style=\"color:#475569;font-size:14px\">This article draws on data and guidance from the following authoritative UK sources:<\/p>\n\n\n\n<ul class=\"wp-block-list\" style=\"font-size:14px\">\n<li><a href=\"https:\/\/www.fensa.org.uk\/find-an-installer\" target=\"_blank\" rel=\"noopener\">FENSA \u2014 Find an installer<\/a> \u2014 primary UK certification for window\/door installers<\/li>\n<li><a href=\"https:\/\/www.certass.co.uk\/find-a-certass-installer\" target=\"_blank\" rel=\"noopener\">Certass \u2014 installer database<\/a> \u2014 alternative UK installer certification<\/li>\n<li><a href=\"https:\/\/www.trustmark.org.uk\/find-a-tradesman\" target=\"_blank\" rel=\"noopener\">Trustmark \u2014 find a tradesman<\/a> \u2014 government-endorsed quality scheme<\/li>\n<li><a href=\"https:\/\/www.ggf.org.uk\/\" target=\"_blank\" rel=\"noopener\">Glass and Glazing Federation (GGF)<\/a> \u2014 UK industry body for glazing professionals<\/li>\n<li><a href=\"https:\/\/find-and-update.company-information.service.gov.uk\/\" target=\"_blank\" rel=\"noopener\">Companies House \u2014 free company lookup<\/a> \u2014 verifying installer registration, directors, filed accounts<\/li>\n<li><a href=\"https:\/\/www.citizensadvice.org.uk\/consumer\/somethings-gone-wrong-with-a-purchase\/problems-with-tradesperson\/\" target=\"_blank\" rel=\"noopener\">Citizens Advice \u2014 rogue traders<\/a> \u2014 consumer rights and complaint routes<\/li>\n<\/ul>\n\n","protected":false},"excerpt":{"rendered":"<p>\ud83d\udcc5 Updated April 2026 \u00b7 \u23f1 Full guide in progress \u00b7 \u270d\ufe0f Findfitter Team Three UK schemes certify replacement window installers: FENSA, Certass, and Trustmark. They sound interchangeable \u2014 they&#8217;re not. Here&#8217;s the short version while our full guide is being finalised. What they have in common All three are Competent Persons Schemes authorised by &#8230; <a title=\"FENSA vs Certass vs Trustmark Explained\" class=\"read-more\" href=\"http:\/\/sadiqur.xyz\/glazing\/index.php\/fensa-certass-trustmark\/\" aria-label=\"Read more about FENSA vs Certass vs Trustmark Explained\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-58","post","type-post","status-publish","format-standard","hentry","category-buyers-guides"],"_links":{"self":[{"href":"http:\/\/sadiqur.xyz\/glazing\/index.php\/wp-json\/wp\/v2\/posts\/58","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/sadiqur.xyz\/glazing\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/sadiqur.xyz\/glazing\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/sadiqur.xyz\/glazing\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/sadiqur.xyz\/glazing\/index.php\/wp-json\/wp\/v2\/comments?post=58"}],"version-history":[{"count":2,"href":"http:\/\/sadiqur.xyz\/glazing\/index.php\/wp-json\/wp\/v2\/posts\/58\/revisions"}],"predecessor-version":[{"id":126,"href":"http:\/\/sadiqur.xyz\/glazing\/index.php\/wp-json\/wp\/v2\/posts\/58\/revisions\/126"}],"wp:attachment":[{"href":"http:\/\/sadiqur.xyz\/glazing\/index.php\/wp-json\/wp\/v2\/media?parent=58"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/sadiqur.xyz\/glazing\/index.php\/wp-json\/wp\/v2\/categories?post=58"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/sadiqur.xyz\/glazing\/index.php\/wp-json\/wp\/v2\/tags?post=58"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}