diff --git a/administration/src/cards/extensions/BirthdayExtension.tsx b/administration/src/cards/extensions/BirthdayExtension.tsx
index cf3bddbb6..77faee184 100644
--- a/administration/src/cards/extensions/BirthdayExtension.tsx
+++ b/administration/src/cards/extensions/BirthdayExtension.tsx
@@ -1,8 +1,10 @@
 import { FormGroup } from '@blueprintjs/core'
-import React, { ReactElement, useState } from 'react'
+import React, { ReactElement, useContext, useState } from 'react'
+import { useTranslation } from 'react-i18next'
 
 import CustomDatePicker from '../../bp-modules/components/CustomDatePicker'
 import FormErrorMessage from '../../bp-modules/self-service/components/FormErrorMessage'
+import { ProjectConfigContext } from '../../project-configs/ProjectConfigContext'
 import PlainDate from '../../util/PlainDate'
 import { Extension, ExtensionComponentProps } from './extensions'
 
@@ -11,6 +13,7 @@ export type BirthdayExtensionState = { [BIRTHDAY_EXTENSION_NAME]: PlainDate | nu
 
 const minBirthday = new PlainDate(1900, 1, 1)
 const getInitialState = (): BirthdayExtensionState => ({ birthday: null })
+let validateUnderAge: boolean
 
 const BirthdayForm = ({
   value,
@@ -21,13 +24,24 @@ const BirthdayForm = ({
   const [touched, setTouched] = useState(false)
   const { birthday } = value
   const showErrorMessage = touched || showRequired
+  const projectConfig = useContext(ProjectConfigContext)
+  validateUnderAge = projectConfig.showBirthdayExtensionHint
+  const { t } = useTranslation('application')
+
   const getErrorMessage = (): string | null => {
+    const today = PlainDate.fromLocalDate(new Date())
+    const underAge = today.subtract({ years: 16 })
+
     if (!birthday) {
       return 'Bitte geben Sie ein gültiges Geburtsdatum an.'
     }
-    if (birthday.isAfter(PlainDate.fromLocalDate(new Date()))) {
+    if (birthday.isAfter(today)) {
       return 'Das Geburtsdatum darf nicht in der Zukunft liegen.'
     }
+    if (birthday.isAfter(underAge) && projectConfig.showBirthdayExtensionHint) {
+      return t('extensions.birthdayHint')
+    }
+
     return null
   }
 
@@ -66,7 +80,9 @@ const BirthdayExtension: Extension<BirthdayExtensionState> = {
       return false
     }
     const today = PlainDate.fromLocalDate(new Date())
-    return !birthday.isBefore(minBirthday) && !birthday.isAfter(today)
+    const underAge = today.subtract({ years: 16 })
+    const underAgeCheck = birthday.isAfter(underAge) && validateUnderAge
+    return !birthday.isBefore(minBirthday) && !birthday.isAfter(today) && !underAgeCheck
   },
   fromString: (value: string) => {
     const birthday = PlainDate.safeFromCustomFormat(value)
diff --git a/administration/src/cards/extensions/extensions.tsx b/administration/src/cards/extensions/extensions.tsx
index 2f85404c2..fabd05e79 100644
--- a/administration/src/cards/extensions/extensions.tsx
+++ b/administration/src/cards/extensions/extensions.tsx
@@ -53,7 +53,6 @@ const Extensions = [
   AddressPlzExtension,
   AddressLocationExtension,
   NuernbergPassIdExtension,
-  NuernbergPassIdExtension,
   EMailNotificationExtension,
   KoblenzReferenceNumberExtension,
 ] as const
diff --git a/administration/src/project-configs/bayern/config.ts b/administration/src/project-configs/bayern/config.ts
index c51997050..3f8323699 100644
--- a/administration/src/project-configs/bayern/config.ts
+++ b/administration/src/project-configs/bayern/config.ts
@@ -93,6 +93,7 @@ const config: ProjectConfig = {
     enabled: false,
   },
   userImportApiEnabled: false,
+  showBirthdayExtensionHint: false,
 }
 
 export default config
diff --git a/administration/src/project-configs/getProjectConfig.ts b/administration/src/project-configs/getProjectConfig.ts
index 51263a6d1..beccd6754 100644
--- a/administration/src/project-configs/getProjectConfig.ts
+++ b/administration/src/project-configs/getProjectConfig.ts
@@ -119,6 +119,7 @@ export type ProjectConfig = {
   selfServiceEnabled: boolean
   storesManagement: StoresManagementConfig
   userImportApiEnabled: boolean
+  showBirthdayExtensionHint: boolean
 }
 
 export const setProjectConfigOverride = (hostname: string): void => {
diff --git a/administration/src/project-configs/koblenz/config.ts b/administration/src/project-configs/koblenz/config.ts
index d2084e629..be3d21114 100644
--- a/administration/src/project-configs/koblenz/config.ts
+++ b/administration/src/project-configs/koblenz/config.ts
@@ -36,6 +36,7 @@ const config: ProjectConfig = {
   selfServiceEnabled: true,
   storesManagement: storesManagementConfig,
   userImportApiEnabled: true,
+  showBirthdayExtensionHint: true,
 }
 
 export default config
diff --git a/administration/src/project-configs/nuernberg/__tests__/csvExport.test.tsx b/administration/src/project-configs/nuernberg/__tests__/csvExport.test.tsx
index 58e71057f..335e47296 100644
--- a/administration/src/project-configs/nuernberg/__tests__/csvExport.test.tsx
+++ b/administration/src/project-configs/nuernberg/__tests__/csvExport.test.tsx
@@ -9,7 +9,10 @@ jest.mock('csv-stringify/browser/esm/sync', () => ({
   stringify: (input: string[][]) => input[0].join(','),
 }))
 
-jest.mock('../../getProjectConfig')
+jest.mock('../../getProjectConfig', () => ({
+  __esModule: true,
+  default: jest.fn(),
+}))
 
 describe('csvExport', () => {
   it('header should have same length as line', () => {
diff --git a/administration/src/project-configs/nuernberg/config.ts b/administration/src/project-configs/nuernberg/config.ts
index d493a758d..e6ed409e9 100644
--- a/administration/src/project-configs/nuernberg/config.ts
+++ b/administration/src/project-configs/nuernberg/config.ts
@@ -61,6 +61,7 @@ const config: ProjectConfig = {
   selfServiceEnabled: false,
   storesManagement: storesManagementConfig,
   userImportApiEnabled: false,
+  showBirthdayExtensionHint: false,
 }
 
 export default config
diff --git a/administration/src/project-configs/showcase/config.ts b/administration/src/project-configs/showcase/config.ts
index 86bccee46..afe035146 100644
--- a/administration/src/project-configs/showcase/config.ts
+++ b/administration/src/project-configs/showcase/config.ts
@@ -36,6 +36,7 @@ const config: ProjectConfig = {
     enabled: false,
   },
   userImportApiEnabled: false,
+  showBirthdayExtensionHint: false,
 }
 
 export default config
diff --git a/administration/src/util/PlainDate.ts b/administration/src/util/PlainDate.ts
index 723906eb7..48c1dd002 100644
--- a/administration/src/util/PlainDate.ts
+++ b/administration/src/util/PlainDate.ts
@@ -1,4 +1,4 @@
-import { add, differenceInCalendarDays, format, isValid, parse } from 'date-fns'
+import { add, differenceInCalendarDays, format, isValid, parse, sub } from 'date-fns'
 
 type DateDuration = { years?: number; months?: number; days?: number }
 
@@ -125,6 +125,15 @@ class PlainDate {
     return PlainDate.fromLocalDate(add(this.toLocalDate(), duration))
   }
 
+  /**
+   * Returns a new PlainDate corresponding to `this` minus `duration`.
+   * @param duration
+   */
+  subtract(duration: DateDuration): PlainDate {
+    // Mirror the add() method but use date-fns/sub
+    return PlainDate.fromLocalDate(sub(this.toLocalDate(), duration))
+  }
+
   /**
    * Returns a new PlainDate corresponding to the result of adding `days` days to 1970-01-01
    * @param days
diff --git a/administration/src/util/translations/de.json b/administration/src/util/translations/de.json
index 54559b8ba..5a558e4b9 100644
--- a/administration/src/util/translations/de.json
+++ b/administration/src/util/translations/de.json
@@ -65,7 +65,10 @@
     "sentSuccessfully": "Erfolgreich gesendet",
     "sentError": "Fehler beim Senden",
     "positiveAnswer": "Ja",
-    "negativeAnswer": "Nein"
+    "negativeAnswer": "Nein",
+    "extensions": {
+      "birthdayHint": "Bei Minderjährigen unter 16 Jahren darf der KoblenzPass nur mit Einverständnis der Erziehungsberechtigten abgerufen werden."
+    }
   },
   "applications": {
     "allApplications": "Alle Anträge",