diff --git a/admin-compliance/app/sdk/dsr/[requestId]/_components/ActionButtons.tsx b/admin-compliance/app/sdk/dsr/[requestId]/_components/ActionButtons.tsx
index 7727b43..a79632f 100644
--- a/admin-compliance/app/sdk/dsr/[requestId]/_components/ActionButtons.tsx
+++ b/admin-compliance/app/sdk/dsr/[requestId]/_components/ActionButtons.tsx
@@ -9,7 +9,8 @@ export function ActionButtons({
   onExtendDeadline,
   onComplete,
   onReject,
-  onAssign
+  onAssign,
+  onRejectArt11,
 }: {
   request: DSRRequest
   onVerifyIdentity: () => void
@@ -17,6 +18,7 @@ export function ActionButtons({
   onComplete: () => void
   onReject: () => void
   onAssign: () => void
+  onRejectArt11?: () => void
 }) {
   const isTerminal = request.status === 'completed' || request.status === 'rejected' || request.status === 'cancelled'
 
@@ -48,12 +50,23 @@ export function ActionButtons({
   return (
     <div className="space-y-2">
       {!request.identityVerification.verified && (
-        <button
-          onClick={onVerifyIdentity}
-          className="w-full px-4 py-2 bg-yellow-500 text-white hover:bg-yellow-600 rounded-lg transition-colors text-sm font-medium"
-        >
-          Identitaet verifizieren
-        </button>
+        <>
+          <button
+            onClick={onVerifyIdentity}
+            className="w-full px-4 py-2 bg-yellow-500 text-white hover:bg-yellow-600 rounded-lg transition-colors text-sm font-medium"
+          >
+            Identitaet verifizieren
+          </button>
+          {onRejectArt11 && (
+            <button
+              onClick={onRejectArt11}
+              className="w-full px-4 py-2 text-gray-600 bg-gray-50 hover:bg-gray-100 border border-gray-200 rounded-lg transition-colors text-sm"
+              title="Person kann anhand der gespeicherten Daten nicht identifiziert werden (Art. 11 DSGVO)"
+            >
+              Nicht identifizierbar (Art. 11)
+            </button>
+          )}
+        </>
       )}
 
       <button
diff --git a/backend-compliance/compliance/api/dsr_routes.py b/backend-compliance/compliance/api/dsr_routes.py
index 0870d8e..4002ebc 100644
--- a/backend-compliance/compliance/api/dsr_routes.py
+++ b/backend-compliance/compliance/api/dsr_routes.py
@@ -243,6 +243,19 @@ async def change_status(
         return svc.change_status(dsr_id, body, tenant_id)
 
 
+@router.post("/{dsr_id}/reject-art11")
+async def reject_art11(
+    dsr_id: str,
+    notes: str = Query(""),
+    tenant_id: str = Depends(_get_tenant),
+    db: Session = Depends(get_db),
+):
+    """Reject DSR under Art. 11 DSGVO — data subject not identifiable."""
+    from compliance.services.dsr_art11_service import DSRArt11Service
+    with translate_domain_errors():
+        return DSRArt11Service(db).reject_not_identifiable(dsr_id, tenant_id, notes)
+
+
 @router.post("/{dsr_id}/verify-identity")
 async def verify_identity(
     dsr_id: str,
diff --git a/backend-compliance/compliance/services/dsr_art11_service.py b/backend-compliance/compliance/services/dsr_art11_service.py
new file mode 100644
index 0000000..1791715
--- /dev/null
+++ b/backend-compliance/compliance/services/dsr_art11_service.py
@@ -0,0 +1,107 @@
+"""
+DSR Art. 11 Service — handles "data subject not identifiable" rejections.
+
+Art. 11 Abs. 1 DSGVO: If the controller is unable to identify the data
+subject, it is not obligated to obtain additional information solely to
+comply with Art. 15-20 requests.
+
+Common scenario: Website visitor requests access, but only anonymous
+cookies/IP-hashes are stored — no way to link to a person.
+"""
+
+import logging
+from datetime import datetime, timezone
+from typing import Any, Dict
+
+from sqlalchemy.orm import Session
+
+from compliance.domain import ValidationError
+
+logger = logging.getLogger(__name__)
+
+
+class DSRArt11Service:
+    """Handles Art. 11 DSGVO rejections for non-identifiable data subjects."""
+
+    def __init__(self, db: Session) -> None:
+        self._db = db
+
+    def reject_not_identifiable(
+        self, dsr_id: str, tenant_id: str, notes: str = "",
+    ) -> Dict[str, Any]:
+        """Reject DSR because data subject cannot be identified."""
+        from compliance.db.dsr_models import DSRRequestDB
+        from compliance.services.dsr_workflow_service import _dsr_to_dict, _record_history
+
+        dsr = (
+            self._db.query(DSRRequestDB)
+            .filter(DSRRequestDB.id == dsr_id, DSRRequestDB.tenant_id == tenant_id)
+            .first()
+        )
+        if not dsr:
+            raise ValidationError("DSR not found")
+        if dsr.status in ("completed", "rejected", "cancelled"):
+            raise ValidationError("DSR already closed")
+
+        now = datetime.now(timezone.utc)
+        reason = (
+            "Die bei uns gespeicherten Daten (anonymisierte Cookies, IP-Hashes, "
+            "Device-Fingerprints) erlauben keine Identifikation der betroffenen Person. "
+            "Gemaess Art. 11 Abs. 1 DSGVO sind wir nicht verpflichtet, zusaetzliche "
+            "Informationen zu erheben, um die betroffene Person zu identifizieren."
+        )
+        if notes:
+            reason += f" Ergaenzung: {notes}"
+
+        _record_history(self._db, dsr, "rejected",
+                        comment="Art. 11 DSGVO — Identifikation nicht moeglich")
+        dsr.status = "rejected"
+        dsr.rejection_reason = reason
+        dsr.rejection_legal_basis = "Art. 11 Abs. 1 DSGVO"
+        dsr.identity_verified = False
+        dsr.verification_method = "art11_not_identifiable"
+        dsr.verification_notes = "Daten erlauben keine Identifikation der betroffenen Person"
+        dsr.completed_at = now
+        dsr.updated_at = now
+        self._db.commit()
+        self._db.refresh(dsr)
+
+        # Send rejection notification
+        self._send_art11_notification(dsr)
+
+        return _dsr_to_dict(dsr)
+
+    def _send_art11_notification(self, dsr: Any) -> None:
+        if not dsr.requester_email:
+            return
+        try:
+            from compliance.services.smtp_sender import send_email
+            send_email(
+                recipient=dsr.requester_email,
+                subject=f"Zu Ihrer Anfrage {dsr.request_number} — Art. 11 DSGVO",
+                body_html=f"""
+                <div style="font-family:system-ui,sans-serif;max-width:600px;margin:0 auto;">
+                    <div style="background:#6b7280;color:white;padding:20px 24px;border-radius:12px 12px 0 0;">
+                        <h1 style="margin:0;font-size:20px;">Mitteilung zu Ihrer Anfrage</h1>
+                    </div>
+                    <div style="background:white;padding:24px;border:1px solid #e5e7eb;border-top:none;border-radius:0 0 12px 12px;">
+                        <p>Sehr geehrte/r Antragsteller/in,</p>
+                        <p>wir haben Ihre Anfrage ({dsr.request_number}) gemaess Art. 15 DSGVO
+                        erhalten und geprueft.</p>
+                        <p>Leider koennen wir die bei uns gespeicherten Daten (anonymisierte
+                        Cookies, IP-Hashes) <strong>keiner identifizierbaren Person zuordnen</strong>.</p>
+                        <p>Gemaess <strong>Art. 11 Abs. 1 DSGVO</strong> sind wir nicht verpflichtet,
+                        zusaetzliche Informationen zu erheben, um Sie zu identifizieren.
+                        Eine Auskunftserteilung ist daher nicht moeglich.</p>
+                        <p>Sollten Sie ueber ein Kundenkonto bei uns verfuegen, koennen Sie
+                        die Anfrage unter Angabe Ihrer Kundennummer erneut einreichen.</p>
+                        <p style="margin-top:24px;color:#6b7280;font-size:12px;">
+                            Mit freundlichen Gruessen<br>
+                            <strong>Datenschutzbeauftragter</strong>
+                        </p>
+                    </div>
+                </div>
+                """,
+            )
+        except Exception as e:
+            logger.warning("Art. 11 notification failed: %s", e)