diff --git a/internal/http/handlers/ticket_handler_test.go b/internal/http/handlers/ticket_handler_test.go
index da02067..d8f48fb 100644
--- a/internal/http/handlers/ticket_handler_test.go
+++ b/internal/http/handlers/ticket_handler_test.go
@@ -46,6 +46,7 @@ type mockTicketService struct {
 	mu            sync.Mutex
 	tickets       *memory.TicketStore
 	auditRecorder *ticketAuditRecorder
+	listErr       error
 	calls         []struct {
 		method string
 		args   []string
@@ -57,6 +58,9 @@ func newMockTicketService(auditRecorder *ticketAuditRecorder) *mockTicketService
 }
 
 func (m *mockTicketService) ListOpen(ctx context.Context, limit int) ([]ticket.Ticket, error) {
+	if m.listErr != nil {
+		return nil, m.listErr
+	}
 	return m.tickets.ListOpen(ctx, limit)
 }
 
@@ -511,3 +515,63 @@ func TestTicketHandlerClose_ReturnsConflictWhenTicketNotResolved(t *testing.T) {
 		t.Fatalf("error code = %v, want CS_TICKET_4093", errPayload["code"])
 	}
 }
+
+func TestTicketHandlerList_Success(t *testing.T) {
+	auditRecorder := &ticketAuditRecorder{}
+	svc := newMockTicketService(auditRecorder)
+	now := time.Date(2026, 4, 29, 21, 0, 0, 0, time.UTC)
+	for i := 0; i < 2; i++ {
+		if err := svc.tickets.Create(context.Background(), &ticket.Ticket{
+			ID:            fmt.Sprintf("ticket-list-%d", i),
+			SessionID:     fmt.Sprintf("session-%d", i),
+			Priority:      ticket.PriorityP1,
+			Status:        ticket.StatusOpen,
+			HandoffReason: "refund",
+			CreatedAt:     now,
+			UpdatedAt:     now,
+		}); err != nil {
+			t.Fatalf("Create() error = %v", err)
+		}
+	}
+	h := NewTicketHandler(svc, auditRecorder)
+	req := httptest.NewRequest(http.MethodGet, "/api/v1/customer-service/tickets", nil)
+	resp := httptest.NewRecorder()
+	h.List(resp, req)
+
+	if resp.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200", resp.Code)
+	}
+	var payload map[string]any
+	if err := json.Unmarshal(resp.Body.Bytes(), &payload); err != nil {
+		t.Fatalf("json decode error = %v", err)
+	}
+	items, ok := payload["items"].([]any)
+	if !ok {
+		t.Fatalf("items field missing or not an array: %v", payload)
+	}
+	if len(items) != 2 {
+		t.Fatalf("items count = %d, want 2", len(items))
+	}
+}
+
+func TestTicketHandlerList_ServiceError(t *testing.T) {
+	auditRecorder := &ticketAuditRecorder{}
+	svc := newMockTicketService(auditRecorder)
+	svc.listErr = fmt.Errorf("db down")
+	h := NewTicketHandler(svc, auditRecorder)
+	req := httptest.NewRequest(http.MethodGet, "/api/v1/customer-service/tickets", nil)
+	resp := httptest.NewRecorder()
+	h.List(resp, req)
+
+	if resp.Code != http.StatusInternalServerError {
+		t.Fatalf("status = %d, want 500", resp.Code)
+	}
+	var payload map[string]any
+	if err := json.Unmarshal(resp.Body.Bytes(), &payload); err != nil {
+		t.Fatalf("json decode error = %v", err)
+	}
+	errPayload := payload["error"].(map[string]any)
+	if errPayload["code"] != "CS_SYS_5002" {
+		t.Fatalf("error code = %v, want CS_SYS_5002", errPayload["code"])
+	}
+}