diff --git a/finance/app/models/views.py b/finance/app/models/views.py
index b8d7846..4c5854f 100644
--- a/finance/app/models/views.py
+++ b/finance/app/models/views.py
@@ -1,6 +1,11 @@
 from sqlalchemy import text
 from sqlalchemy.engine import Engine
 
+# Serienname der Ist-Kurve im Grafana-Panel „Szenario-Vergleich" (v_projection).
+# Für Szenarien reserviert (routers/scenarios.py lehnt ihn ab), damit kein
+# Szenario mit der Ist-Serie verschmelzen kann (Ausbaustufe 11).
+RESERVED_SCENARIO_NAME = "System-Ist"
+
 # Per-account offset for the Konto-Saldo-Anker (Ausbaustufe 3 Task 1): the
 # same math as app.services.balances.account_balance, expressed as a single
 # constant "base" per account so it can be added to a plain (anchor-agnostic)
diff --git a/finance/app/routers/scenarios.py b/finance/app/routers/scenarios.py
index 70db717..325859c 100644
--- a/finance/app/routers/scenarios.py
+++ b/finance/app/routers/scenarios.py
@@ -13,6 +13,7 @@ from app.db import get_session
 from app.models.tables import (Loan, ProjectionPoint, ProjectionResult,
                                Scenario, ScenarioLoan, ScenarioModifier,
                                ScenarioPlannedItem)
+from app.models.views import RESERVED_SCENARIO_NAME
 from app.services.projection_service import run_projection
 
 router = APIRouter(prefix="/api/scenarios", tags=["scenarios"],
@@ -85,6 +86,14 @@ def _get_scenario(session: Session, scenario_id: int) -> Scenario:
     return scenario
 
 
+def _check_reserved_name(name: str | None) -> None:
+    """Der Serienname der Ist-Kurve (v_projection) ist für Szenarien tabu."""
+    if name is not None and (name.strip().casefold()
+                             == RESERVED_SCENARIO_NAME.casefold()):
+        raise HTTPException(
+            422, f"Der Name »{RESERVED_SCENARIO_NAME}« ist für die Ist-Kurve reserviert")
+
+
 @router.get("", response_model=list[ScenarioOut])
 def list_scenarios(session: Session = Depends(get_session)):
     return [ScenarioOut.model_validate(s)
@@ -93,6 +102,7 @@ def list_scenarios(session: Session = Depends(get_session)):
 
 @router.post("", response_model=ScenarioOut, status_code=201)
 def create_scenario(data: ScenarioIn, session: Session = Depends(get_session)):
+    _check_reserved_name(data.name)
     if session.execute(select(Scenario).where(Scenario.name == data.name)).scalar():
         raise HTTPException(409, "Szenario existiert bereits")
     scenario = Scenario(**data.model_dump())
@@ -107,6 +117,7 @@ def patch_scenario(scenario_id: int, data: ScenarioPatch,
                    session: Session = Depends(get_session)):
     scenario = _get_scenario(session, scenario_id)
     fields = data.model_dump(exclude_unset=True)
+    _check_reserved_name(fields.get("name"))
     if "name" in fields and fields["name"] != scenario.name:
         clash = session.execute(
             select(Scenario).where(Scenario.name == fields["name"])).scalar()
diff --git a/finance/app/templates/szenarien.html b/finance/app/templates/szenarien.html
index 953b1db..cee2f10 100644
--- a/finance/app/templates/szenarien.html
+++ b/finance/app/templates/szenarien.html
@@ -13,6 +13,9 @@
       · Wiederkehrende Posten: {{ 'ja' if sc.include_recurring else 'nein' }}
       · Einmalposten: {{ 'ja' if sc.include_planned else 'nein' }}
       <button type="button" onclick="toggleEdit('sc', {{ sc.id }}, true)">Bearbeiten</button>
+      <button type="button" hx-delete="/api/scenarios/{{ sc.id }}" hx-swap="none"
+              hx-confirm="Szenario „{{ sc.name }}" mit allen Einträgen wirklich löschen?"
+              hx-on::after-request="if(event.detail.successful){window.location.reload()}">Löschen</button>
     </p>
     <div id="sc-edit-{{ sc.id }}" hidden>
       <form hx-ext="json-form" hx-patch="/api/scenarios/{{ sc.id }}" hx-swap="none"
diff --git a/finance/tests/test_crud_api.py b/finance/tests/test_crud_api.py
index 5713f7e..dbc003b 100644
--- a/finance/tests/test_crud_api.py
+++ b/finance/tests/test_crud_api.py
@@ -1,6 +1,8 @@
 from datetime import date, timedelta
 from decimal import Decimal
 
+import pytest
+
 from app.models.tables import Account, Transaction
 from app.services.balances import account_balance
 
@@ -294,3 +296,25 @@ def test_scenario_planned_patch(client, db):
     r = client.patch(f"/api/scenarios/{other['id']}/planned/{p['id']}", headers=H, json={
         "name": "x", "amount": "1.00", "due": "2026-08-15"})
     assert r.status_code == 404
+
+
+@pytest.mark.parametrize("name", ["System-Ist", "system-ist", "  System-Ist  ", "SYSTEM-IST"])
+def test_szenario_name_system_ist_ist_reserviert_post(client, name):
+    r = client.post("/api/scenarios", json={"name": name}, headers=H)
+    assert r.status_code == 422
+    assert "reserviert" in r.json()["detail"]
+
+
+def test_szenario_name_system_ist_ist_reserviert_patch(client):
+    sid = client.post("/api/scenarios", json={"name": "Normal"}, headers=H).json()["id"]
+    r = client.patch(f"/api/scenarios/{sid}", json={"name": "System-Ist"}, headers=H)
+    assert r.status_code == 422
+    assert "reserviert" in r.json()["detail"]
+    # Andere Felder ohne Namensänderung bleiben erlaubt.
+    r = client.patch(f"/api/scenarios/{sid}", json={"description": "x"}, headers=H)
+    assert r.status_code == 200
+
+
+def test_szenario_normale_namen_weiter_erlaubt(client):
+    assert client.post("/api/scenarios", json={"name": "Ist-Zustand plus"},
+                       headers=H).status_code == 201
diff --git a/finance/tests/test_gui.py b/finance/tests/test_gui.py
index 6809d19..d197692 100644
--- a/finance/tests/test_gui.py
+++ b/finance/tests/test_gui.py
@@ -483,3 +483,24 @@ def test_grafana_links_fallback_to_host_port_when_unset(client, monkeypatch):
         assert "fb.example.de" not in r.text
     finally:
         get_settings.cache_clear()
+
+
+def test_szenarien_seite_hat_loeschen_button(client, db):
+    client.post("/login", data={"username": "admin", "password": "geheim"})
+    sc = Scenario(name="Wegwerf", description="", include_recurring=True,
+                  include_planned=True)
+    db.add(sc)
+    db.commit()
+    r = client.get("/szenarien")
+    assert f'hx-delete="/api/scenarios/{sc.id}"' in r.text
+    assert 'Szenario „Wegwerf" mit allen Einträgen wirklich löschen?' in r.text
+
+
+def test_szenario_loeschen_roundtrip_gui(client, db):
+    client.post("/login", data={"username": "admin", "password": "geheim"})
+    sc = Scenario(name="Wegwerf-Roundtrip", description="", include_recurring=True,
+                  include_planned=True)
+    db.add(sc)
+    db.commit()
+    assert client.delete(f"/api/scenarios/{sc.id}", headers=H).status_code == 204
+    assert "Wegwerf-Roundtrip" not in client.get("/szenarien").text