diff --git a/nextjs-app/__tests__/components/SecondarySchoolRow.test.tsx b/nextjs-app/__tests__/components/SecondarySchoolRow.test.tsx
new file mode 100644
index 0000000..affaecb
--- /dev/null
+++ b/nextjs-app/__tests__/components/SecondarySchoolRow.test.tsx
@@ -0,0 +1,46 @@
+/**
+ * SecondarySchoolRow — sixth-form tag must come from the GIAS
+ * has_sixth_form flag, not the age_range-contains-"18" heuristic.
+ */
+
+import '@testing-library/jest-dom';
+import { render, screen } from '@testing-library/react';
+import { SecondarySchoolRow } from '@/components/SecondarySchoolRow';
+import type { School } from '@/lib/types';
+
+const base = {
+  urn: 100002,
+  school_name: 'Beta Sixth Form College',
+  local_authority: 'Testshire',
+  school_type: 'Academy',
+  phase: 'Secondary',
+  gender: 'Mixed',
+  attainment_8_score: 50.0,
+} as unknown as School;
+
+describe('SecondarySchoolRow sixth-form tag', () => {
+  it('shows the tag for a 16-19 college with the GIAS flag set', () => {
+    render(
+      <SecondarySchoolRow
+        school={{ ...base, age_range: '16-19', has_sixth_form: true }}
+      />,
+    );
+    expect(screen.getByText('Sixth form')).toBeInTheDocument();
+  });
+
+  it('hides the tag for an 11-18 school without a registered sixth form', () => {
+    render(
+      <SecondarySchoolRow
+        school={{ ...base, age_range: '11-18', has_sixth_form: false }}
+      />,
+    );
+    expect(screen.queryByText('Sixth form')).not.toBeInTheDocument();
+  });
+
+  it('hides the tag when the flag is missing (pipeline not yet re-run)', () => {
+    render(
+      <SecondarySchoolRow school={{ ...base, age_range: '11-18' }} />,
+    );
+    expect(screen.queryByText('Sixth form')).not.toBeInTheDocument();
+  });
+});
diff --git a/nextjs-app/components/FilterBar.tsx b/nextjs-app/components/FilterBar.tsx
index 51ee0eb..91abf00 100644
--- a/nextjs-app/components/FilterBar.tsx
+++ b/nextjs-app/components/FilterBar.tsx
@@ -368,8 +368,8 @@ export function FilterBar({
                     disabled={isPending}
                   >
                     <option value="">With or without sixth form</option>
-                    <option value="yes">With sixth form (11-18)</option>
-                    <option value="no">Without sixth form (11-16)</option>
+                    <option value="yes">With sixth form</option>
+                    <option value="no">Without sixth form</option>
                   </select>
 
                   {admissionsPolicyOptions.length > 0 && (
diff --git a/nextjs-app/components/SecondarySchoolDetailView.tsx b/nextjs-app/components/SecondarySchoolDetailView.tsx
index a8e8b2c..8210313 100644
--- a/nextjs-app/components/SecondarySchoolDetailView.tsx
+++ b/nextjs-app/components/SecondarySchoolDetailView.tsx
@@ -98,7 +98,8 @@ export function SecondarySchoolDetailView({
 
   const secondaryAvg = nationalAvg?.secondary ?? {};
 
-  const hasSixthForm = schoolInfo.age_range?.includes('18') ?? false;
+  // GIAS OfficialSixthForm flag; missing (pipeline not yet re-run) => false.
+  const hasSixthForm = schoolInfo.has_sixth_form ?? false;
   const hasFinance = finance != null && finance.per_pupil_spend != null;
   const hasDeprivation = deprivation != null && deprivation.idaci_decile != null;
   const hasLocation = schoolInfo.latitude != null && schoolInfo.longitude != null;
diff --git a/nextjs-app/components/SecondarySchoolRow.tsx b/nextjs-app/components/SecondarySchoolRow.tsx
index 61097ae..c32dab4 100644
--- a/nextjs-app/components/SecondarySchoolRow.tsx
+++ b/nextjs-app/components/SecondarySchoolRow.tsx
@@ -23,7 +23,8 @@ function detectAdmissionsTag(school: School): string | null {
 }
 
 function hasSixthForm(school: School): boolean {
-  return school.age_range?.includes('18') ?? false;
+  // GIAS OfficialSixthForm flag; missing (pipeline not yet re-run) => false.
+  return school.has_sixth_form ?? false;
 }
 
 interface SecondarySchoolRowProps {
diff --git a/nextjs-app/lib/types.ts b/nextjs-app/lib/types.ts
index 816516e..dc1cd2a 100644
--- a/nextjs-app/lib/types.ts
+++ b/nextjs-app/lib/types.ts
@@ -17,6 +17,7 @@ export interface School {
   school_type_code: string | null;
   religious_denomination: string | null;
   age_range: string | null;
+  has_sixth_form?: boolean | null;
 
   // Address
   address1: string | null;