diff --git a/api/src/certification/enrolment/application/api/candidates-api.js b/api/src/certification/enrolment/application/api/candidates-api.js
new file mode 100644
index 00000000000..c5c5dbe850b
--- /dev/null
+++ b/api/src/certification/enrolment/application/api/candidates-api.js
@@ -0,0 +1,17 @@
+import { usecases } from '../../../enrolment/domain/usecases/index.js';
+
+/**
+ * Checks if a user has been candidate to a certification
+ *
+ * @function
+ * @param {Object} params
+ * @param {number} params.userId user id to search for candidates
+ * @returns {Promise<boolean>}
+ * @throws {TypeError} preconditions failed
+ */
+export const hasBeenCandidate = async ({ userId }) => {
+  if (!userId) {
+    throw new TypeError('user identifier is required');
+  }
+  return usecases.hasBeenCandidate({ userId });
+};
diff --git a/api/src/certification/enrolment/domain/usecases/has-been-candidate.js b/api/src/certification/enrolment/domain/usecases/has-been-candidate.js
new file mode 100644
index 00000000000..23f08af82bd
--- /dev/null
+++ b/api/src/certification/enrolment/domain/usecases/has-been-candidate.js
@@ -0,0 +1,13 @@
+/**
+ * @typedef {import('./index.js').CandidateRepository} CandidateRepository
+ */
+
+/**
+ * @param {Object} params
+ * @param {number} params.userId
+ * @param {CandidateRepository} params.candidateRepository
+ */
+export async function hasBeenCandidate({ userId, candidateRepository }) {
+  const candidates = await candidateRepository.findByUserId({ userId });
+  return candidates.some((candidate) => candidate.isReconciled());
+}
diff --git a/api/src/certification/enrolment/infrastructure/repositories/candidate-repository.js b/api/src/certification/enrolment/infrastructure/repositories/candidate-repository.js
index d5e1bb6dc21..50a1633bdb2 100644
--- a/api/src/certification/enrolment/infrastructure/repositories/candidate-repository.js
+++ b/api/src/certification/enrolment/infrastructure/repositories/candidate-repository.js
@@ -35,6 +35,19 @@ export async function findBySessionId({ sessionId }) {
   return candidatesData.map(toDomain);
 }
 
+/**
+ * @function
+ * @param {Object} params
+ * @param {number} params.userId
+ *
+ * @return {Promise<Array<Candidate>>}
+ */
+export async function findByUserId({ userId }) {
+  const knexTransaction = DomainTransaction.getConnection();
+  const candidatesData = await buildBaseReadQuery(knexTransaction).where({ 'certification-candidates.userId': userId });
+  return candidatesData.map(toDomain);
+}
+
 /**
  * @function
  * @param {Object} candidate
diff --git a/api/tests/certification/enrolment/integration/infrastructure/repositories/candidate-repository_test.js b/api/tests/certification/enrolment/integration/infrastructure/repositories/candidate-repository_test.js
index ecd8489984b..19138906ffd 100644
--- a/api/tests/certification/enrolment/integration/infrastructure/repositories/candidate-repository_test.js
+++ b/api/tests/certification/enrolment/integration/infrastructure/repositories/candidate-repository_test.js
@@ -4,7 +4,7 @@ import * as candidateRepository from '../../../../../../src/certification/enrolm
 import { SUBSCRIPTION_TYPES } from '../../../../../../src/certification/shared/domain/constants.js';
 import { catchErr, databaseBuilder, domainBuilder, expect, knex } from '../../../../../test-helper.js';
 
-describe('Integration | Certification | Session | Repository | Candidate', function () {
+describe('Integration | Certification | Enrolment | Repository | Candidate', function () {
   describe('#get', function () {
     context('when the candidate exists', function () {
       it('should return the candidate', async function () {
@@ -128,6 +128,49 @@ describe('Integration | Certification | Session | Repository | Candidate', funct
     });
   });
 
+  describe('#findByUserId', function () {
+    context('when there are candidates', function () {
+      it('should return the candidates', async function () {
+        // given
+        const candidate1 = databaseBuilder.factory.buildCertificationCandidate();
+        databaseBuilder.factory.buildCoreSubscription({ certificationCandidateId: candidate1.id });
+        const userId = candidate1.userId;
+
+        const candidate2 = databaseBuilder.factory.buildCertificationCandidate({ userId });
+        databaseBuilder.factory.buildCoreSubscription({ certificationCandidateId: candidate2.id });
+
+        const candidate3 = databaseBuilder.factory.buildCertificationCandidate();
+        databaseBuilder.factory.buildCoreSubscription({ certificationCandidateId: candidate3.id });
+        await databaseBuilder.commit();
+
+        // when
+        const result = await candidateRepository.findByUserId({ userId });
+
+        // then
+        expect(result).to.deepEqualArray([
+          domainBuilder.certification.enrolment.buildCandidate({
+            ...candidate1,
+            subscriptions: [domainBuilder.buildCoreSubscription({ certificationCandidateId: candidate1.id })],
+          }),
+          domainBuilder.certification.enrolment.buildCandidate({
+            ...candidate2,
+            subscriptions: [domainBuilder.buildCoreSubscription({ certificationCandidateId: candidate2.id })],
+          }),
+        ]);
+      });
+    });
+
+    context('when there are no candidates', function () {
+      it('returns an empty array', async function () {
+        //when
+        const result = await candidateRepository.findByUserId({ userId: 123 });
+
+        // then
+        expect(result).to.be.empty;
+      });
+    });
+  });
+
   describe('#update', function () {
     context('when the candidate exists', function () {
       it('should update the candidate', async function () {
diff --git a/api/tests/certification/enrolment/unit/application/api/candidates-api_test.js b/api/tests/certification/enrolment/unit/application/api/candidates-api_test.js
new file mode 100644
index 00000000000..1675d21ae2c
--- /dev/null
+++ b/api/tests/certification/enrolment/unit/application/api/candidates-api_test.js
@@ -0,0 +1,30 @@
+import { hasBeenCandidate } from '../../../../../../src/certification/enrolment/application/api/candidates-api.js';
+import { usecases } from '../../../../../../src/certification/enrolment/domain/usecases/index.js';
+import { catchErr, expect, sinon } from '../../../../../test-helper.js';
+
+describe('Unit | Certification | Enrolment | API | candidates-api', function () {
+  describe('hasBeenCandidate', function () {
+    it('should check if a user has been candidate', async function () {
+      // given
+      sinon.stub(usecases, 'hasBeenCandidate').resolves();
+
+      // when
+      await hasBeenCandidate({ userId: 12 });
+
+      // then
+      expect(usecases.hasBeenCandidate).to.have.been.calledOnceWithExactly({ userId: 12 });
+    });
+
+    it('should reject calls without a userId', async function () {
+      // given
+      sinon.stub(usecases, 'hasBeenCandidate').resolves();
+
+      // when
+      const error = await catchErr(() => hasBeenCandidate({ userId: null }))();
+
+      // then
+      expect(error).to.be.instanceOf(TypeError);
+      expect(error.message).to.equals('user identifier is required');
+    });
+  });
+});
diff --git a/api/tests/certification/enrolment/unit/domain/usecases/has-been-candidate_test.js b/api/tests/certification/enrolment/unit/domain/usecases/has-been-candidate_test.js
new file mode 100644
index 00000000000..13f3243f304
--- /dev/null
+++ b/api/tests/certification/enrolment/unit/domain/usecases/has-been-candidate_test.js
@@ -0,0 +1,58 @@
+import { hasBeenCandidate } from '../../../../../../src/certification/enrolment/domain/usecases/has-been-candidate.js';
+import { domainBuilder, expect, sinon } from '../../../../../test-helper.js';
+
+describe('Certification | Enrolment | Unit | UseCase | has-been-candidate', function () {
+  let candidateRepository;
+
+  beforeEach(function () {
+    candidateRepository = { findByUserId: sinon.stub() };
+  });
+
+  context('when at least one candidate is reconciled', function () {
+    it('should return true', async function () {
+      // given
+      const candidate1 = domainBuilder.certification.enrolment.buildCandidate({
+        userId: 4321,
+        reconciledAt: new Date(),
+      });
+      const candidate2 = domainBuilder.certification.enrolment.buildCandidate({ userId: 4321 });
+
+      candidateRepository.findByUserId.withArgs({ userId: 4321 }).resolves([candidate1, candidate2]);
+
+      // when
+      const result = await hasBeenCandidate({ userId: 4321, candidateRepository });
+
+      // then
+      expect(result).to.be.true;
+    });
+  });
+
+  context('when no candidates are reconciled', function () {
+    it('should return false', async function () {
+      // given
+      const candidate1 = domainBuilder.certification.enrolment.buildCandidate({ userId: 4321 });
+      const candidate2 = domainBuilder.certification.enrolment.buildCandidate({ userId: 4321 });
+
+      candidateRepository.findByUserId.withArgs({ userId: 4321 }).resolves([candidate1, candidate2]);
+
+      // when
+      const result = await hasBeenCandidate({ userId: 4321, candidateRepository });
+
+      // then
+      expect(result).to.be.false;
+    });
+  });
+
+  context('when no candidates are returned', function () {
+    it('should return false', async function () {
+      // given
+      candidateRepository.findByUserId.withArgs({ userId: 4321 }).resolves([]);
+
+      // when
+      const result = await hasBeenCandidate({ userId: 4321, candidateRepository });
+
+      // then
+      expect(result).to.be.false;
+    });
+  });
+});