diff --git a/app.py b/app.py
index 3b8348a..6fc78fc 100644
--- a/app.py
+++ b/app.py
@@ -90,6 +90,11 @@ class CreateOrganizationRequest(BaseModel):
 
 class UpdateOrganizationRequest(BaseModel):
     name: str
+    kontakt_name: str | None = None
+    adresse: str | None = None
+    telefon: str | None = None
+    kontakt_email: str | None = None
+    notizen: str | None = None
 
 
 class CreateMerkmalRequest(BaseModel):
@@ -1604,22 +1609,42 @@ def archive_device(device_id: str) -> bool:
             )
             return cur.fetchone() is not None
 
+ORGANIZATION_KONTAKTFELDER = ("kontakt_name", "adresse", "telefon", "kontakt_email", "notizen")
+
 def fetch_organizations():
     with get_database_connection() as conn:
         with conn.cursor() as cur:
             cur.execute(
-                "SELECT id, name, created_at FROM organizations ORDER BY name"
+                """
+                SELECT id, name, created_at, kontakt_name, adresse, telefon, kontakt_email, notizen
+                FROM organizations ORDER BY name
+                """
             )
             return [
-                {"id": str(org_id), "name": name, "created_at": created_at.isoformat()}
-                for org_id, name, created_at in cur.fetchall()
+                {
+                    "id": str(org_id),
+                    "name": name,
+                    "created_at": created_at.isoformat(),
+                    "kontakt_name": kontakt_name,
+                    "adresse": adresse,
+                    "telefon": telefon,
+                    "kontakt_email": kontakt_email,
+                    "notizen": notizen,
+                }
+                for (
+                    org_id, name, created_at,
+                    kontakt_name, adresse, telefon, kontakt_email, notizen,
+                ) in cur.fetchall()
             ]
 
 def fetch_organization(organization_id: str):
     with get_database_connection() as conn:
         with conn.cursor() as cur:
             cur.execute(
-                "SELECT id, name, created_at FROM organizations WHERE id = %s",
+                """
+                SELECT id, name, created_at, kontakt_name, adresse, telefon, kontakt_email, notizen
+                FROM organizations WHERE id = %s
+                """,
                 (organization_id,),
             )
             row = cur.fetchone()
@@ -1627,7 +1652,16 @@ def fetch_organization(organization_id: str):
     if row is None:
         return None
 
-    return {"id": str(row[0]), "name": row[1], "created_at": row[2].isoformat()}
+    return {
+        "id": str(row[0]),
+        "name": row[1],
+        "created_at": row[2].isoformat(),
+        "kontakt_name": row[3],
+        "adresse": row[4],
+        "telefon": row[5],
+        "kontakt_email": row[6],
+        "notizen": row[7],
+    }
 
 def create_organization(name: str):
     organization_id = uuid4()
@@ -1652,12 +1686,26 @@ def create_organization(name: str):
 
     return {"id": str(organization_id), "name": name}
 
-def update_organization(organization_id: str, name: str):
+def update_organization(organization_id: str, name: str, kontaktfelder: dict):
     with get_database_connection() as conn:
         with conn.cursor() as cur:
             cur.execute(
-                "UPDATE organizations SET name = %s WHERE id = %s RETURNING id, name",
-                (name, organization_id),
+                """
+                UPDATE organizations
+                SET name = %s, kontakt_name = %s, adresse = %s, telefon = %s,
+                    kontakt_email = %s, notizen = %s
+                WHERE id = %s
+                RETURNING id, name
+                """,
+                (
+                    name,
+                    kontaktfelder.get("kontakt_name"),
+                    kontaktfelder.get("adresse"),
+                    kontaktfelder.get("telefon"),
+                    kontaktfelder.get("kontakt_email"),
+                    kontaktfelder.get("notizen"),
+                    organization_id,
+                ),
             )
             row = cur.fetchone()
 
@@ -2691,7 +2739,8 @@ def update_organization_endpoint(
             "message": "Fehlendes oder ungültiges Service-Token.",
         }
 
-    organization = update_organization(organization_id, payload.name)
+    kontaktfelder = {feld: getattr(payload, feld) for feld in ORGANIZATION_KONTAKTFELDER}
+    organization = update_organization(organization_id, payload.name, kontaktfelder)
 
     if organization is None:
         return {
diff --git a/migrations/0020_organization_kontaktdaten.sql b/migrations/0020_organization_kontaktdaten.sql
new file mode 100644
index 0000000..958fcfa
--- /dev/null
+++ b/migrations/0020_organization_kontaktdaten.sql
@@ -0,0 +1,16 @@
+BEGIN;
+
+-- Kontakt-/Stammdaten je Organisation (Ansprechpartner, Adresse, Telefon,
+-- Kontakt-E-Mail, Notizen) - bislang hatte organizations ausser dem Namen
+-- keine Felder. Bewusst nur einfache Stammdaten, keine Richtlinien-/
+-- Sicherheitsfelder (Network Profile/Secret Reference bleiben laut
+-- ADR-0001/09-data-model-v1.md weiterhin unspezifiziert, eigenstaendiges
+-- Thema). Alle Spalten nullable - kein Pflichtfeld, bestehende und neue
+-- Organisationen starten leer.
+ALTER TABLE organizations ADD COLUMN kontakt_name TEXT;
+ALTER TABLE organizations ADD COLUMN adresse TEXT;
+ALTER TABLE organizations ADD COLUMN telefon TEXT;
+ALTER TABLE organizations ADD COLUMN kontakt_email TEXT;
+ALTER TABLE organizations ADD COLUMN notizen TEXT;
+
+COMMIT;