diff --git a/apps/web/src/portal/CustomerPortal.tsx b/apps/web/src/portal/CustomerPortal.tsx
index 2a5d424..2547664 100644
--- a/apps/web/src/portal/CustomerPortal.tsx
+++ b/apps/web/src/portal/CustomerPortal.tsx
@@ -42,6 +42,9 @@ export function CustomerPortal() {
   // Track whether we've attempted to fetch a session — used to prevent premature redirect
   // when a session fetch is in-flight (E2E mocks resolve synchronously, batched with setInitComplete)
   const [sessionAttempted, setSessionAttempted] = useState(false);
+  // Track whether an impersonation session fetch from URL param is in-flight
+  // Dashboard will not redirect while this is true, allowing the session to load
+  const [isImpersonating, setIsImpersonating] = useState(false);
   const { branding } = useBranding();
   const [searchParams, setSearchParams] = useSearchParams();
 
@@ -54,6 +57,7 @@ export function CustomerPortal() {
     const sessionId = searchParams.get("sessionId");
 
     if (sessionId) {
+      setIsImpersonating(true);
       // Real impersonation session from URL param
       fetch(`/api/impersonation/sessions/${sessionId}`)
         .then((r) => {
@@ -75,7 +79,7 @@ export function CustomerPortal() {
           setSessionAttempted(true);
           setSearchParams({}, { replace: true });
         })
-        .finally(() => setInitComplete(true));
+        .finally(() => { setInitComplete(true); setIsImpersonating(false); });
       return;
     }
 
@@ -162,7 +166,7 @@ export function CustomerPortal() {
     const sessionId = session?.id ?? null;
     switch (activeSection) {
       case "dashboard":
-        return <Dashboard onNavigate={handleNavClick} readOnly={!!isReadOnly} sessionId={sessionId} clientName={clientName} onReschedule={handleReschedule} />;
+        return <Dashboard onNavigate={handleNavClick} readOnly={!!isReadOnly} sessionId={sessionId} clientName={clientName} onReschedule={handleReschedule} isImpersonating={isImpersonating} />;
       case "appointments":
         return <AppointmentsSection readOnly={!!isReadOnly} sessionId={sessionId} />;
       case "pets":
diff --git a/apps/web/src/portal/sections/Dashboard.tsx b/apps/web/src/portal/sections/Dashboard.tsx
index f252e8a..bf6f0e4 100644
--- a/apps/web/src/portal/sections/Dashboard.tsx
+++ b/apps/web/src/portal/sections/Dashboard.tsx
@@ -8,6 +8,8 @@ interface DashboardProps {
   onNavigate: (section: "appointments" | "pets" | "billing" | "reports") => void;
   readOnly: boolean;
   onReschedule: (appointmentId: string) => void;
+  /** True when a sessionId param was in the URL and the session is still loading */
+  isImpersonating?: boolean;
 }
 
 interface Appointment {
@@ -73,6 +75,7 @@ export function Dashboard({
   onNavigate,
   readOnly,
   onReschedule,
+  isImpersonating,
 }: DashboardProps) {
   const [appointments, setAppointments] = useState<Appointment[]>([]);
   const [pets, setPets] = useState<Pet[]>([]);
@@ -183,7 +186,7 @@ export function Dashboard({
     );
   }
 
-  if (!sessionId) {
+  if (!sessionId && !isImpersonating) {
     return <Navigate to="/login" replace />;
   }