diff --git a/tests/tools/test_browser_cleanup_owner_scope.py b/tests/tools/test_browser_cleanup_owner_scope.py
new file mode 100644
index 0000000000..801402d17d
--- /dev/null
+++ b/tests/tools/test_browser_cleanup_owner_scope.py
@@ -0,0 +1,52 @@
+"""Shutdown teardown runs each session under the profile that owns it.
+
+``cleanup_all_browsers`` (gateway shutdown, atexit) runs outside any profile scope, like the janitor. A cloud
+session belongs to the provider and credentials of the profile that created it: closed under the launch
+profile's scope instead, a multiplexed profile's Browserbase / Browser Use session is never closed (the launch
+profile has no such provider) and keeps billing until the provider's own timeout.
+"""
+
+import pytest
+
+from hermes_constants import get_hermes_home
+from tools import browser_launcher as launcher
+from tools import browser_session as bs
+from tools import browser_session_cloud
+from tools import browser_session_lifecycle as lifecycle
+
+
+@pytest.fixture
+def isolated_sessions(monkeypatch):
+    for name in ("_active_sessions", "_session_last_activity", "_session_owner_homes", "_cleanup_failures"):
+        monkeypatch.setattr(bs, name, {})
+    monkeypatch.setattr(launcher, "_browsers", {})
+    monkeypatch.setattr(lifecycle, "start_cleanup_thread", lambda: None)
+    return bs._active_sessions
+
+
+class _ProfileProvider:
+    """The cloud provider the CURRENT profile scope resolves, recording which profile closed what."""
+
+    closed: list = []
+
+    def __init__(self):
+        self.home = str(get_hermes_home())
+
+    def close_session(self, session_id):
+        _ProfileProvider.closed.append((self.home, session_id))
+
+
+def test_shutdown_closes_each_cloud_session_under_its_owning_profile(tmp_path, monkeypatch, isolated_sessions):
+    launch, routed = tmp_path / "launch", tmp_path / "routed"
+    for home in (launch, routed):
+        home.mkdir()
+    monkeypatch.setenv("HERMES_HOME", str(launch))
+    monkeypatch.setattr(_ProfileProvider, "closed", [])
+    monkeypatch.setattr(browser_session_cloud, "get_cloud_provider", _ProfileProvider)
+    isolated_sessions["task@routed"] = {"session_name": "bb_1", "bb_session_id": "bb-routed", "features": {},
+                                        "cdp_url": "wss://cloud.example/x"}
+    bs._session_owner_homes["task@routed"] = str(routed)
+
+    lifecycle.cleanup_all_browsers()
+
+    assert _ProfileProvider.closed == [(str(routed), "bb-routed")]
diff --git a/tools/browser_session_lifecycle.py b/tools/browser_session_lifecycle.py
index 68b05e8a9e..8f5ebdaf3a 100644
--- a/tools/browser_session_lifecycle.py
+++ b/tools/browser_session_lifecycle.py
@@ -196,13 +196,20 @@ def cleanup_profile_browsers(home_key: str) -> None:
     reset_caches(home_key)
 
 
+def _cleanup_in_owner_scope(cache_key: str) -> None:
+    with _session_owner_scope(cache_key):
+        cleanup_single_session(cache_key)
+
+
 def cleanup_all_browsers() -> None:
-    """Close every session (gateway shutdown), stop every browser this process launched, reset caches."""
+    """Close every session (gateway shutdown), stop every browser this process launched, reset caches. Each
+    session is closed under its owning profile, as the janitor does: a cloud session belongs to that profile's
+    provider and credentials."""
     bs = _bs()
     with bs._cleanup_lock:
         keys = list(bs._active_sessions)
     for key in keys:
-        _best_effort(f"browser cleanup for {key}", lambda key=key: cleanup_single_session(key))
+        _best_effort(f"browser cleanup for {key}", lambda key=key: _cleanup_in_owner_scope(key))
 
     def _stop_supervisors():
         from tools.browser_supervisor import SUPERVISOR_REGISTRY