diff --git a/kyc/quiz/quiz.go b/kyc/quiz/quiz.go
index e8c35a52..5b429411 100644
--- a/kyc/quiz/quiz.go
+++ b/kyc/quiz/quiz.go
@@ -202,17 +202,63 @@ func wrapErrorInTx(err error) error {
 	return err
 }
 
-func (r *repositoryImpl) StartQuizSession(ctx context.Context, userID UserID, lang string) (*Quiz, error) { //nolint:funlen //.
-	err := r.CheckUserKYC(ctx, userID)
+func (r *repositoryImpl) finishExpiredSession( //nolint:funlen //.
+	ctx context.Context,
+	userID UserID,
+	now *time.Time,
+	tx storage.QueryExecer,
+) (*time.Time, error) {
+	// $1: user_id.
+	// $2: max session duration (seconds).
+	// $3: session cool down (seconds).
+	const stmt = `
+	with result as (
+		update quiz_sessions
+		set
+			ended_at = now(),
+			ended_successfully = false
+		where
+			user_id = $1 and
+			ended_at is null and
+			started_at + make_interval(secs => $2) < now()
+		returning *
+	)
+	insert into failed_quiz_sessions (started_at, ended_at, questions, answers, language, user_id, skipped)
+	select
+		result.started_at,
+		result.ended_at,
+		result.questions,
+		result.answers,
+		result.language,
+		result.user_id,
+		false
+	from
+		result
+	returning
+		ended_at + make_interval(secs => $3) as cooldown_at
+	`
+	data, err := storage.ExecOne[struct {
+		CooldownAt *time.Time `db:"cooldown_at"`
+	}](ctx, tx, stmt, userID, r.config.MaxSessionDurationSeconds, r.config.SessionCoolDownSeconds)
 	if err != nil {
-		return nil, err
-	}
+		if errors.Is(err, storage.ErrNotFound) {
+			err = nil
+		}
 
-	questions, err := r.SelectQuestions(ctx, r.DB, lang)
-	if err != nil {
 		return nil, err
 	}
 
+	return data.CooldownAt, errors.Wrapf(r.modifyUser(ctx, false, now, userID), "failed to modifyUser")
+}
+
+func (r *repositoryImpl) startNewSession( //nolint:funlen,revive //.
+	ctx context.Context,
+	userID UserID,
+	now *time.Time,
+	tx storage.QueryExecer,
+	lang string,
+	questions []*Question,
+) (*Quiz, error) {
 	// $1: user_id.
 	// $2: language.
 	// $3: questions.
@@ -297,7 +343,7 @@ func (r *repositoryImpl) StartQuizSession(ctx context.Context, userID UserID, la
 		ActiveEndedAt           *time.Time `db:"active_ended_at"`
 		UpsertStartedAt         *time.Time `db:"upsert_started_at"`
 		UpsertDeadline          *time.Time `db:"upsert_deadline"`
-	}](ctx, r.DB, stmt, userID, lang, questionsToSlice(questions), r.config.SessionCoolDownSeconds, r.config.MaxSessionDurationSeconds)
+	}](ctx, tx, stmt, userID, lang, questionsToSlice(questions), r.config.SessionCoolDownSeconds, r.config.MaxSessionDurationSeconds)
 	if err != nil {
 		if errors.Is(err, storage.ErrRelationNotFound) {
 			err = ErrUnknownUser
@@ -306,7 +352,6 @@ func (r *repositoryImpl) StartQuizSession(ctx context.Context, userID UserID, la
 		return nil, errors.Wrap(err, "failed to start session")
 	}
 
-	now := stdlibtime.Now().Truncate(stdlibtime.Second).UTC()
 	switch {
 	case data.FailedAt != nil: // Failed session is still in cool down.
 		return nil, errors.Wrapf(ErrSessionFinishedWithError, "wait until %v",
@@ -321,8 +366,8 @@ func (r *repositoryImpl) StartQuizSession(ctx context.Context, userID UserID, la
 			return nil, ErrSessionFinishedWithError
 		}
 
-		if data.ActiveDeadline.After(now) {
-			return nil, errors.Wrapf(ErrSessionIsAlreadyRunning, "wait %s before next session", data.ActiveDeadline.Sub(now))
+		if data.ActiveDeadline.After(*now.Time) {
+			return nil, errors.Wrapf(ErrSessionIsAlreadyRunning, "wait %s before next session", data.ActiveDeadline.Sub(*now.Time))
 		}
 
 	case data.UpsertStartedAt != nil: // New session is started.
@@ -338,6 +383,34 @@ func (r *repositoryImpl) StartQuizSession(ctx context.Context, userID UserID, la
 	panic("unreachable: " + userID)
 }
 
+func (r *repositoryImpl) StartQuizSession(ctx context.Context, userID UserID, lang string) (quiz *Quiz, err error) {
+	err = r.CheckUserKYC(ctx, userID)
+	if err != nil {
+		return nil, err
+	}
+
+	questions, err := r.SelectQuestions(ctx, r.DB, lang)
+	if err != nil {
+		return nil, err
+	}
+
+	err = storage.DoInTransaction(ctx, r.DB, func(tx storage.QueryExecer) error {
+		now := time.Now()
+		cooldown, fErr := r.finishExpiredSession(ctx, userID, now, tx)
+		if fErr != nil {
+			return wrapErrorInTx(fErr)
+		} else if cooldown != nil {
+			return wrapErrorInTx(errors.Wrapf(ErrSessionFinishedWithError, "wait until %v", cooldown))
+		}
+
+		quiz, err = r.startNewSession(ctx, userID, now, tx, lang, questions)
+
+		return wrapErrorInTx(err)
+	})
+
+	return quiz, err
+}
+
 func calculateProgress(correctAnswers, currentAnswers []uint8) (correctNum, incorrectNum uint8) {
 	correct := correctAnswers
 	if len(currentAnswers) < len(correctAnswers) {
diff --git a/kyc/quiz/quiz_test.go b/kyc/quiz/quiz_test.go
index f6ff25da..39b49e8f 100644
--- a/kyc/quiz/quiz_test.go
+++ b/kyc/quiz/quiz_test.go
@@ -164,13 +164,8 @@ func testManagerSessionStart(ctx context.Context, t *testing.T, r *repositoryImp
 		t.Run("Expired", func(t *testing.T) {
 			helperForceResetSessionStartedAt(t, r, "bogus")
 			session, err := r.StartQuizSession(ctx, "bogus", "en")
-			require.NoError(t, err)
-			require.NotNil(t, session)
-			require.NotNil(t, session.Progress)
-			require.NotNil(t, session.Progress.ExpiresAt)
-			require.NotEmpty(t, session.Progress.NextQuestion)
-			require.Equal(t, uint8(3), session.Progress.MaxQuestions)
-			require.Equal(t, uint8(1), session.Progress.NextQuestion.Number)
+			require.ErrorIs(t, err, ErrSessionFinishedWithError)
+			require.Nil(t, session)
 		})
 		t.Run("CoolDown", func(t *testing.T) {
 			helperSessionReset(t, r, "bogus", true)