diff --git a/Website/main.py b/Website/main.py
index 13d0015..c15a503 100644
--- a/Website/main.py
+++ b/Website/main.py
@@ -2451,7 +2451,7 @@ def booking_payment():
     packages_str = _sanitize_text(request.values.get("packages") or request.values.get("package") or "", 200).lower()
     booking_flow = _sanitize_text(request.values.get("flow") or "payment", 24).lower()
     
-    is_trial = (booking_flow == "trial") or request.values.get("is_trial", "").strip().lower() in {"1", "on", "true", "yes"}
+    is_trial = (booking_flow == "testversion") or request.values.get("testversion", "").strip().lower() in {"1", "on", "true", "yes"}
     trial_days = int(request.values.get("trial_days") or 14)
 
     if booking_flow not in BOOKING_FLOW_MAP and booking_flow != "trial":
@@ -2587,14 +2587,14 @@ def booking_payment():
             flash(f"Gesprächstermin für {selected_package} wurde an das Team gesendet.", "success")
             return redirect(url_for("user_chat"))
             
-        if booking_flow in ["payment", "trial"]:
+        if booking_flow in ["payment", "testversion"]:
             # CORRECTED: Syntax error in the f-string is fixed below (uses single quotes inside double quotes)
             booking_number = f"{'TRIAL' if is_trial else 'BOOK'}-{datetime.utcnow().strftime('%Y%m%d%H%M%S')}"
 
             raw_base = form_data.get("tenant_slug") or form_data.get("school_name") or session.get("username") or booking_number
             base = _slugify_subdomain(raw_base).lower()[:51]
             
-            effective_subdomain = f"testversion-{base}" if (is_trial and not base.startswith("testversion-")) else base
+            effective_subdomain = base
 
             inst_check_client, inst_col_check = _get_collection("instances")
             try: