diff --git a/backend/handlers/bookings/bookings.go b/backend/handlers/bookings/bookings.go
index 4ae9ff8..85861b6 100644
--- a/backend/handlers/bookings/bookings.go
+++ b/backend/handlers/bookings/bookings.go
@@ -1268,6 +1268,18 @@ func CreateBookingHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// Check for overlapping bookings with confirmed/in_progress/completed status
+	// Users cannot book a time slot that overlaps with these statuses
+	var cnt int
+	db.DB.QueryRow(r.Context(), `
+		SELECT COUNT(*) FROM bookings WHERE status IN ('confirmed','in_progress','completed') AND start_time < $2 AND start_time + (INTERVAL '1 minute' * (SELECT COALESCE(SUM(COALESCE(bs.override_duration_minutes,s.duration_minutes)),60) FROM booking_services bs JOIN services s ON bs.service_id=s.id WHERE bs.booking_id=bookings.id)) > $1
+	`, req.StartTime, endTime).Scan(&cnt)
+	if cnt > 0 {
+		http.Error(w, "Cannot book this time - slot overlaps with an existing booking", http.StatusConflict)
+		return
+	}
+
+
 
 	// Get created by from context (if available)
 	var createdBy *string