diff --git a/src/features/users/__tests__/confirm-newsletter-subscriptions.spec.ts b/src/features/users/__tests__/confirm-newsletter-subscriptions.spec.ts
index 7beb89f3..5066e553 100644
--- a/src/features/users/__tests__/confirm-newsletter-subscriptions.spec.ts
+++ b/src/features/users/__tests__/confirm-newsletter-subscriptions.spec.ts
@@ -324,23 +324,23 @@ describe('Given a NGC user', () => {
     })
 
     describe('And user already has a brevo contact with some subscribed news letters', () => {
-      beforeEach(async () => {
-        ;({
-          id: userId,
-          listIds,
-          email,
-          code,
-        } = await subscribeToNewsLetter({
-          agent,
-          user: {
-            contact: {
-              listIds: [ListIds.LOGEMENT_NEWSLETTER],
+      describe('When clicking the confirmation email link', () => {
+        beforeEach(async () => {
+          ;({
+            id: userId,
+            listIds,
+            email,
+            code,
+          } = await subscribeToNewsLetter({
+            agent,
+            user: {
+              contact: {
+                listIds: [ListIds.LOGEMENT_NEWSLETTER],
+              },
             },
-          },
-        }))
-      })
+          }))
+        })
 
-      describe('When clicking the confirmation email link', () => {
         test('Then it redirects to a success page', async () => {
           mswServer.use(
             brevoGetContact(email, {
@@ -389,6 +389,77 @@ describe('Given a NGC user', () => {
           )
         })
       })
+
+      describe('And unknown newletter', () => {
+        describe('When clicking the confirmation email link', () => {
+          beforeEach(async () => {
+            ;({
+              id: userId,
+              listIds,
+              email,
+              code,
+            } = await subscribeToNewsLetter({
+              agent,
+              user: {
+                contact: {
+                  listIds: [ListIds.LOGEMENT_NEWSLETTER],
+                },
+              },
+            }))
+          })
+
+          test('Then it redirects to a success page', async () => {
+            mswServer.use(
+              brevoGetContact(email, {
+                customResponses: [
+                  {
+                    body: getBrevoContact({
+                      email,
+                      attributes: {
+                        USER_ID: userId,
+                      },
+                      listIds: [ListIds.MAIN_NEWSLETTER, 404],
+                    }),
+                  },
+                ],
+              }),
+              brevoRemoveFromList(ListIds.MAIN_NEWSLETTER, {
+                expectBody: {
+                  emails: [email],
+                },
+              }),
+              brevoUpdateContact({
+                expectBody: {
+                  email,
+                  attributes: {
+                    USER_ID: userId,
+                    PRENOM: null,
+                  },
+                  updateEnabled: true,
+                  listIds: expect.arrayContaining([
+                    ListIds.LOGEMENT_NEWSLETTER,
+                    404,
+                  ]),
+                },
+              })
+            )
+
+            const response = await agent
+              .get(url.replace(':userId', userId))
+              .query({
+                code,
+                email,
+                listIds: [...listIds, 404],
+                origin: 'https://nosgestesclimat.fr',
+              })
+              .expect(StatusCodes.MOVED_TEMPORARILY)
+
+            expect(response.get('location')).toBe(
+              'https://nosgestesclimat.fr/newsletter-confirmation?success=true'
+            )
+          })
+        })
+      })
     })
   })
 
diff --git a/src/features/users/__tests__/update-user.spec.ts b/src/features/users/__tests__/update-user.spec.ts
index 881520b7..be22ec2c 100644
--- a/src/features/users/__tests__/update-user.spec.ts
+++ b/src/features/users/__tests__/update-user.spec.ts
@@ -704,6 +704,64 @@ describe('Given a NGC user', () => {
               })
             })
 
+            describe('And contact has already subscribed an unknown newsletter', () => {
+              beforeEach(() => {
+                contact.listIds = [404]
+              })
+
+              test(`Then it sends an email and returns a ${StatusCodes.ACCEPTED} response`, async () => {
+                const payload = {
+                  email,
+                  contact: {
+                    listIds: [ListIds.MAIN_NEWSLETTER],
+                  },
+                }
+
+                mswServer.use(
+                  brevoGetContact(email, {
+                    customResponses: [
+                      {
+                        body: contact,
+                      },
+                    ],
+                  }),
+                  brevoSendEmail({
+                    expectBody: {
+                      to: [
+                        {
+                          name: email,
+                          email,
+                        },
+                      ],
+                      templateId: 118,
+                      params: {
+                        NEWSLETTER_CONFIRMATION_URL: `https://server.nosgestesclimat.fr/users/v1/${userId}/newsletter-confirmation?code=${code}&email=${encodeURIComponent(email)}&origin=${encodeURIComponent('https://preprod.nosgestesclimat.fr')}&listIds=22&listIds=404`,
+                      },
+                    },
+                  })
+                )
+
+                const { body } = await agent
+                  .put(url.replace(':userId', userId))
+                  .set('origin', 'https://preprod.nosgestesclimat.fr')
+                  .send(payload)
+                  .expect(StatusCodes.ACCEPTED)
+
+                expect(body).toEqual({
+                  id: userId,
+                  email,
+                  name: null,
+                  contact: {
+                    id: contact.id,
+                    email,
+                    listIds: [404],
+                  },
+                  createdAt: expect.any(String),
+                  updatedAt: expect.any(String),
+                })
+              })
+            })
+
             describe('And no email provided', () => {
               test(`Then it returns a ${StatusCodes.OK} response with the updated user`, async () => {
                 const { body } = await agent
@@ -1155,6 +1213,62 @@ describe('Given a NGC user', () => {
               })
             })
 
+            describe('And contact has already subscribed an unknown newsletter', () => {
+              beforeEach(() => {
+                contact.listIds = [404]
+              })
+
+              test(`Then it sends an email and returns a ${StatusCodes.ACCEPTED} response`, async () => {
+                const payload = {
+                  contact: {
+                    listIds: [ListIds.MAIN_NEWSLETTER],
+                  },
+                }
+
+                mswServer.use(
+                  brevoGetContact(email, {
+                    customResponses: [
+                      {
+                        body: contact,
+                      },
+                    ],
+                  }),
+                  brevoSendEmail({
+                    expectBody: {
+                      to: [
+                        {
+                          name: email,
+                          email,
+                        },
+                      ],
+                      templateId: 118,
+                      params: {
+                        NEWSLETTER_CONFIRMATION_URL: `https://server.nosgestesclimat.fr/users/v1/${userId}/newsletter-confirmation?code=${code}&email=${encodeURIComponent(email)}&origin=${encodeURIComponent('https://nosgestesclimat.fr')}&listIds=22&listIds=404`,
+                      },
+                    },
+                  })
+                )
+
+                const { body } = await agent
+                  .put(url.replace(':userId', userId))
+                  .send(payload)
+                  .expect(StatusCodes.ACCEPTED)
+
+                expect(body).toEqual({
+                  id: userId,
+                  email,
+                  name: null,
+                  contact: {
+                    id: contact.id,
+                    email,
+                    listIds: [404],
+                  },
+                  createdAt: expect.any(String),
+                  updatedAt: expect.any(String),
+                })
+              })
+            })
+
             describe('And contact has already subscribed to the newsletter', () => {
               beforeEach(() => {
                 contact.listIds = [ListIds.MAIN_NEWSLETTER]
@@ -1809,7 +1923,7 @@ describe('Given a NGC user', () => {
               })
             })
 
-            test(`Then it returns a ${StatusCodes.ACCEPTED} response`, async () => {
+            test(`Then it returns a ${StatusCodes.OK} response`, async () => {
               const payload = {
                 contact: {
                   listIds: [],
diff --git a/src/features/users/users.service.ts b/src/features/users/users.service.ts
index 4c2fd467..30fccf47 100644
--- a/src/features/users/users.service.ts
+++ b/src/features/users/users.service.ts
@@ -48,7 +48,7 @@ const getNewsletterMutation = ({
 }: {
   contact?: BrevoContact
   previousContact?: BrevoContact
-  wantedNewsletters?: ListIds[]
+  wantedNewsletters?: number[]
 }) => {
   const newslettersToSubscribe = new Set<number>()
   const newslettersToUnsubscribe = new Set<number>()
diff --git a/src/features/users/users.validator.ts b/src/features/users/users.validator.ts
index 88a09f01..b51c397e 100644
--- a/src/features/users/users.validator.ts
+++ b/src/features/users/users.validator.ts
@@ -65,11 +65,13 @@ export const NewsletterConfirmationQuery = z
       .transform((email) => email.toLocaleLowerCase()),
     listIds: z
       .union([
-        z.coerce.number().pipe(z.nativeEnum(ListIds).transform((s) => [s])),
-        z.array(z.coerce.number().pipe(z.nativeEnum(ListIds))),
+        z.coerce.number().positive(),
+        z.array(z.coerce.number().positive()),
       ])
       .optional()
-      .transform((listIds) => listIds || []),
+      .transform((listIds) =>
+        typeof listIds === 'number' ? [listIds] : listIds || []
+      ),
   })
   .strict()