diff --git a/backend/app/routers/transfer.py b/backend/app/routers/transfer.py
index 726d235..443523c 100644
--- a/backend/app/routers/transfer.py
+++ b/backend/app/routers/transfer.py
@@ -11,12 +11,13 @@ import io
 import json
 from datetime import date, datetime, timezone
 
-from fastapi import APIRouter, Depends, File, HTTPException, UploadFile, status
+from fastapi import APIRouter, Body, Depends, File, HTTPException, UploadFile, status
 from fastapi.responses import Response
 from sqlalchemy.orm import Session
 
 from ..database import get_db
 from ..deps import get_current_user, require_admin
+from ..services.master_data import export_master_data, import_master_data
 from ..services.dates import MONTH, clean_precision, normalize_best_before
 from ..services.group_codes import sync as sync_group_code
 from ..models import (
@@ -252,6 +253,30 @@ def export_backup_json(
     )
 
 
+@router.get("/export/master-data")
+def export_masterdata(
+    db: Session = Depends(get_db), _: User = Depends(require_admin)
+) -> dict:
+    """Stammdaten (Kategorien, Felder, Lagerorte, Einheiten, Gebinde) als JSON –
+    mit IDs, für Sicherung/Umzug."""
+    return export_master_data(db)
+
+
+@router.post("/import/master-data")
+def import_masterdata(
+    payload: dict = Body(...),
+    mode: str = "skip",
+    db: Session = Depends(get_db),
+    _: User = Depends(require_admin),
+) -> dict:
+    """Stammdaten aus JSON einspielen. mode=skip (Vorhandenes lassen) oder
+    overwrite (per ID überschreiben). IDs werden aus der Datei übernommen."""
+    try:
+        return import_master_data(db, payload, mode=mode)
+    except ValueError as e:
+        raise HTTPException(status.HTTP_400_BAD_REQUEST, str(e))
+
+
 @router.get("/export/labels")
 def export_labels(
     category_ids: str | None = None,
diff --git a/backend/app/services/master_data.py b/backend/app/services/master_data.py
new file mode 100644
index 0000000..9905e7c
--- /dev/null
+++ b/backend/app/services/master_data.py
@@ -0,0 +1,180 @@
+"""Export/Import der Stammdaten als JSON – mit ID-Erhalt für Sicherung/Umzug.
+
+Umfasst Kategorien (inkl. eigener Felder), Lagerorte, Einheiten und Gebinde. Die
+IDs werden bewusst mitgeführt: nur so passen z.B. gedruckte Lagerort-QR-Codes
+(`/l/<id>`) nach einem Wiederherstellen noch, und Verweise (parent_id,
+category_id) bleiben gültig.
+
+Beim Import entscheidet der Modus, was bei bereits vergebener ID passiert:
+- ``skip``      – vorhandene Einträge unangetastet lassen, nur neue anlegen.
+- ``overwrite`` – vorhandene per ID überschreiben, fehlende anlegen.
+
+Einzelne Zeilen, die an einer Eindeutigkeit scheitern (z.B. gleicher Name unter
+anderer ID), werden per Savepoint übersprungen statt den ganzen Import
+abzubrechen.
+"""
+
+from __future__ import annotations
+
+import json
+
+from sqlalchemy import text
+from sqlalchemy.orm import Session
+
+from ..models import Category, FieldDefinition, Location, PackageType, Unit, UnitKind
+from .fields import options_list
+
+FORMAT_KEY = "vorrania_master_data"
+FORMAT_VERSION = 1
+_TABLES = ("units", "package_types", "categories", "field_definitions", "locations")
+
+
+def export_master_data(db: Session) -> dict:
+    return {
+        FORMAT_KEY: FORMAT_VERSION,
+        "categories": [
+            {"id": c.id, "name": c.name, "parent_id": c.parent_id, "tracking": c.tracking}
+            for c in db.query(Category).order_by(Category.id).all()
+        ],
+        "field_definitions": [
+            {
+                "id": f.id, "category_id": f.category_id, "label": f.label, "key": f.key,
+                "field_type": f.field_type, "unit": f.unit, "options": options_list(f),
+                "required": f.required, "position": f.position, "is_builtin": f.is_builtin,
+            }
+            for f in db.query(FieldDefinition).order_by(FieldDefinition.id).all()
+        ],
+        "locations": [
+            {"id": l.id, "name": l.name, "parent_id": l.parent_id}
+            for l in db.query(Location).order_by(Location.id).all()
+        ],
+        "units": [
+            {"id": u.id, "name": u.name, "kind": u.kind.value, "factor": u.factor,
+             "is_builtin": u.is_builtin}
+            for u in db.query(Unit).order_by(Unit.id).all()
+        ],
+        "package_types": [
+            {"id": p.id, "singular": p.singular, "plural": p.plural, "is_builtin": p.is_builtin}
+            for p in db.query(PackageType).order_by(PackageType.id).all()
+        ],
+    }
+
+
+class _Report:
+    def __init__(self) -> None:
+        self.created: dict[str, int] = {}
+        self.updated: dict[str, int] = {}
+        self.skipped: dict[str, int] = {}
+
+    def add(self, bucket: dict[str, int], key: str) -> None:
+        bucket[key] = bucket.get(key, 0) + 1
+
+    def as_dict(self) -> dict:
+        return {"created": self.created, "updated": self.updated, "skipped": self.skipped}
+
+
+def _fix_sequence(db: Session, table: str) -> None:
+    """Postgres: die id-Sequenz auf MAX(id) heben, sonst kollidieren spätere
+    Auto-IDs mit importierten. SQLite braucht das nicht."""
+    if db.get_bind().dialect.name != "postgresql":
+        return
+    db.execute(text(
+        f"SELECT setval(pg_get_serial_sequence('{table}', 'id'), "
+        f"GREATEST((SELECT COALESCE(MAX(id), 1) FROM {table}), 1))"
+    ))
+
+
+def import_master_data(db: Session, data: dict, mode: str = "skip") -> dict:
+    if not isinstance(data, dict) or FORMAT_KEY not in data:
+        raise ValueError("Das ist keine Vorrania-Stammdaten-Datei.")
+    overwrite = mode == "overwrite"
+    rep = _Report()
+
+    def upsert(model, row, key, build, *, is_tree=False, conflict=None) -> None:
+        rid = row.get("id")
+        existing = db.get(model, rid) if rid is not None else None
+        if existing is not None and not overwrite:
+            rep.add(rep.skipped, key)
+            return
+        # Vorab-Check statt IntegrityError abzufangen: würde die Zeile eine
+        # Eindeutigkeit unter ANDERER id verletzen (z.B. gleicher Name), lieber
+        # überspringen als den Import abbrechen.
+        if conflict is not None and conflict(row):
+            rep.add(rep.skipped, key)
+            return
+        if existing is not None:
+            for k, v in build(row).items():
+                setattr(existing, k, v)
+            db.flush()
+            rep.add(rep.updated, key)
+            return
+        kwargs = build(row)
+        if rid is not None:
+            kwargs["id"] = rid
+        if is_tree:
+            kwargs["parent_id"] = None  # Eltern erst im 2. Durchgang
+        db.add(model(**kwargs))
+        db.flush()
+        rep.add(rep.created, key)
+
+    def set_parents(model, rows) -> None:
+        for row in rows or []:
+            rid = row.get("id")
+            obj = db.get(model, rid) if rid is not None else None
+            if obj is None:
+                continue
+            pid = row.get("parent_id")
+            ziel = db.get(model, pid) if pid is not None else None
+            obj.parent_id = ziel.id if ziel is not None else None
+        db.flush()
+
+    def name_clash(model, field, r):
+        val = r.get(field)
+        return db.query(model.id).filter(
+            getattr(model, field) == val, model.id != r.get("id")
+        ).first() is not None
+
+    for row in data.get("units") or []:
+        upsert(Unit, row, "units", lambda r: {
+            "name": r["name"], "kind": UnitKind(r["kind"]),
+            "factor": float(r.get("factor", 1.0)),
+            "is_builtin": bool(r.get("is_builtin", False)),
+        }, conflict=lambda r: name_clash(Unit, "name", r))
+    for row in data.get("package_types") or []:
+        upsert(PackageType, row, "package_types", lambda r: {
+            "singular": r["singular"], "plural": r.get("plural") or r["singular"],
+            "is_builtin": bool(r.get("is_builtin", False)),
+        }, conflict=lambda r: name_clash(PackageType, "singular", r))
+
+    cats = data.get("categories") or []
+    for row in cats:
+        upsert(Category, row, "categories", lambda r: {
+            "name": r["name"], "tracking": r.get("tracking") or "food",
+        }, is_tree=True)
+    set_parents(Category, cats)
+
+    for row in data.get("field_definitions") or []:
+        if db.get(Category, row.get("category_id")) is None:
+            rep.add(rep.skipped, "field_definitions")
+            continue
+        upsert(FieldDefinition, row, "field_definitions", lambda r: {
+            "category_id": r["category_id"], "label": r["label"],
+            "key": r.get("key") or r["label"],
+            "field_type": r.get("field_type", "text"),
+            "unit": r.get("unit"),
+            "options": json.dumps(r.get("options") or []) if r.get("field_type") == "select" else None,
+            "required": bool(r.get("required", False)),
+            "position": int(r.get("position", 0)),
+            "is_builtin": bool(r.get("is_builtin", False)),
+        })
+
+    locs = data.get("locations") or []
+    for row in locs:
+        upsert(Location, row, "locations", lambda r: {"name": r["name"]}, is_tree=True)
+    set_parents(Location, locs)
+
+    db.commit()
+    for table in _TABLES:
+        _fix_sequence(db, table)
+    db.commit()
+    return rep.as_dict()
diff --git a/backend/tests/test_master_data.py b/backend/tests/test_master_data.py
new file mode 100644
index 0000000..0fc3ed7
--- /dev/null
+++ b/backend/tests/test_master_data.py
@@ -0,0 +1,91 @@
+"""Stammdaten-Export/Import (JSON) mit ID-Erhalt und Konfliktmodi."""
+
+import pytest
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+from sqlalchemy.pool import StaticPool
+
+from app.database import Base
+from app.models import Category, FieldDefinition, Location, PackageType, Unit
+from app.services.master_data import (
+    FORMAT_KEY,
+    export_master_data,
+    import_master_data,
+)
+
+
+def _fresh_db():
+    engine = create_engine(
+        "sqlite://", connect_args={"check_same_thread": False}, poolclass=StaticPool
+    )
+    Base.metadata.create_all(bind=engine)
+    return sessionmaker(bind=engine, autoflush=False, autocommit=False)()
+
+
+def test_roundtrip_erhaelt_ids_und_baum(db):
+    ober = Category(name="Elektronik", tracking="object")
+    db.add(ober)
+    db.flush()
+    unter = Category(name="Kabel", parent_id=ober.id, tracking="object")
+    db.add(unter)
+    db.flush()
+    db.add(FieldDefinition(category_id=ober.id, label="Kapazität", key="kapazitaet",
+                           field_type="number", unit="mAh"))
+    haus = Location(name="Hedingen")
+    db.add(haus)
+    db.flush()
+    keller = Location(name="Keller", parent_id=haus.id)
+    db.add(keller)
+    beutel = PackageType(singular="Beutel", plural="Beutel")
+    db.add(beutel)
+    db.commit()
+    beutel_id = beutel.id
+
+    data = export_master_data(db)
+
+    ziel = _fresh_db()
+    import_master_data(ziel, data, mode="skip")
+
+    assert ziel.get(Category, ober.id).name == "Elektronik"
+    assert ziel.get(Category, unter.id).parent_id == ober.id      # Baum erhalten
+    assert ziel.get(Location, keller.id).parent_id == haus.id
+    assert ziel.query(FieldDefinition).filter_by(category_id=ober.id).first().label == "Kapazität"
+    assert ziel.get(PackageType, beutel_id).singular == "Beutel"  # id erhalten
+
+
+def test_skip_laesst_vorhandenes_unangetastet(db):
+    a = Location(name="Alt")
+    db.add(a)
+    db.commit()
+    data = {FORMAT_KEY: 1, "locations": [{"id": a.id, "name": "Neu"}]}
+    rep = import_master_data(db, data, mode="skip")
+    assert db.get(Location, a.id).name == "Alt"
+    assert rep["skipped"].get("locations") == 1
+
+
+def test_overwrite_aktualisiert_per_id(db):
+    a = Location(name="Alt")
+    db.add(a)
+    db.commit()
+    data = {FORMAT_KEY: 1, "locations": [{"id": a.id, "name": "Neu"}]}
+    rep = import_master_data(db, data, mode="overwrite")
+    assert db.get(Location, a.id).name == "Neu"
+    assert rep["updated"].get("locations") == 1
+
+
+def test_falsche_datei_wirft():
+    with pytest.raises(ValueError):
+        import_master_data(_fresh_db(), {"foo": 1})
+
+
+def test_namenskonflikt_wird_uebersprungen_nicht_abgebrochen(db):
+    # Vorhandene Einheit unter id X; Import bringt gleichen Namen unter anderer id.
+    vorhanden = Unit(name="Spezialeinheit", kind="count", factor=1)
+    db.add(vorhanden)
+    db.commit()
+    data = {FORMAT_KEY: 1, "units": [{"id": vorhanden.id + 999, "name": "Spezialeinheit",
+                                      "kind": "count", "factor": 1}]}
+    rep = import_master_data(db, data, mode="skip")
+    # Gleicher Name unter neuer id -> Eindeutigkeit verletzt -> uebersprungen.
+    assert rep["skipped"].get("units") == 1
+    assert db.query(Unit).filter_by(name="Spezialeinheit").count() == 1
diff --git a/web/src/api.js b/web/src/api.js
index 53510cc..6f9e43b 100644
--- a/web/src/api.js
+++ b/web/src/api.js
@@ -197,6 +197,11 @@ export const api = {
   setGroupLocationMinStock: (id, list) =>
     request(`/groups/${id}/location-min-stock`, { method: "PUT", body: list }),
 
+  // Stammdaten sichern/wiederherstellen (Kategorien, Lagerorte, Einheiten, Gebinde)
+  exportMasterData: () => request("/export/master-data"),
+  importMasterData: (data, mode = "skip") =>
+    request(`/import/master-data?mode=${mode}`, { method: "POST", body: data }),
+
   // Views
   shoppingList: () => request("/shopping-list"),
   groupShoppingList: () => request("/shopping-list/groups"),
diff --git a/web/src/pages/Locations.jsx b/web/src/pages/Locations.jsx
index 990f369..22adc73 100644
--- a/web/src/pages/Locations.jsx
+++ b/web/src/pages/Locations.jsx
@@ -32,7 +32,8 @@ export default function Locations() {
     try {
       await api.createLocation({ name, parent_id: parentId === "" ? null : Number(parentId) });
       setName("");
-      setParentId("");
+      // Übergeordneten Ort absichtlich stehen lassen – beim Anlegen vieler Orte
+      // unter demselben Elternteil spart das jedes Mal die Neuauswahl.
       load();
     } catch (err) {
       setError(err.message);
diff --git a/web/src/pages/Transfer.jsx b/web/src/pages/Transfer.jsx
index 5b33e4d..9fb49ba 100644
--- a/web/src/pages/Transfer.jsx
+++ b/web/src/pages/Transfer.jsx
@@ -75,6 +75,11 @@ export default function Transfer() {
   const [locations, setLocations] = useState([]);
   const [locBusy, setLocBusy] = useState(false);
   const [locInfo, setLocInfo] = useState(null);
+  // Stammdaten-Sicherung (Kategorien/Lagerorte/Einheiten/Gebinde als JSON).
+  const mdFileRef = useRef(null);
+  const [mdMode, setMdMode] = useState("skip");
+  const [mdBusy, setMdBusy] = useState(false);
+  const [mdInfo, setMdInfo] = useState(null);
 
   useEffect(() => {
     api.listCategories().then(setCategories).catch(() => {});
@@ -93,6 +98,33 @@ export default function Transfer() {
     URL.revokeObjectURL(url);
   }
 
+  async function exportMasterData() {
+    setError(null); setMdInfo(null); setMdBusy(true);
+    try {
+      const data = await api.exportMasterData();
+      downloadCsv(JSON.stringify(data, null, 2), "vorrania-stammdaten.json");
+      setMdInfo("Stammdaten exportiert.");
+    } catch (err) { setError(err.message); } finally { setMdBusy(false); }
+  }
+
+  async function importMasterData(e) {
+    e.preventDefault();
+    const f = mdFileRef.current?.files?.[0];
+    if (!f) return;
+    setError(null); setMdInfo(null); setMdBusy(true);
+    try {
+      const data = JSON.parse(await f.text());
+      const rep = await api.importMasterData(data, mdMode);
+      const summe = (o) => Object.values(o || {}).reduce((a, b) => a + b, 0);
+      setMdInfo(`Import fertig: ${summe(rep.created)} angelegt, ${summe(rep.updated)} aktualisiert, ${summe(rep.skipped)} übersprungen.`);
+      if (mdFileRef.current) mdFileRef.current.value = "";
+      api.listLocations().then(setLocations).catch(() => {});
+      api.listCategories().then(setCategories).catch(() => {});
+    } catch (err) {
+      setError(err instanceof SyntaxError ? "Datei ist kein gültiges JSON." : err.message);
+    } finally { setMdBusy(false); }
+  }
+
   function exportLocationLabels() {
     setError(null);
     setLocInfo(null);
@@ -294,6 +326,41 @@ export default function Transfer() {
         </section>
       </div>
 
+      <section className="card">
+        <div className="card-head"><Icon name="box" /><h2>Stammdaten sichern &amp; wiederherstellen (JSON)</h2></div>
+        <p className="muted small mt-0">
+          Kategorien (inkl. eigener Felder), Lagerorte, Einheiten und Gebinde als <strong>eine
+          JSON-Datei</strong>. Die <strong>IDs kommen mit</strong> – so passen gedruckte
+          Lagerort-QR-Codes nach dem Wiederherstellen noch und Verweise bleiben gültig. Gut für
+          Umzug auf einen neuen Server oder als Sicherung. (Artikel/Bestände: siehe „Backup als
+          JSON" oben.)
+        </p>
+        <div className="grid-2">
+          <div>
+            <button className="btn primary" disabled={mdBusy} onClick={exportMasterData}>
+              <Icon name="download" size={16} />Stammdaten exportieren
+            </button>
+          </div>
+          <form onSubmit={importMasterData}>
+            <label>
+              Datei (JSON)
+              <input ref={mdFileRef} type="file" accept="application/json,.json" />
+            </label>
+            <label>
+              Bei bereits vergebener ID
+              <select value={mdMode} onChange={(e) => setMdMode(e.target.value)}>
+                <option value="skip">Vorhandenes behalten (nur Neues anlegen)</option>
+                <option value="overwrite">Überschreiben (per ID aktualisieren)</option>
+              </select>
+            </label>
+            <button className="btn" disabled={mdBusy}>
+              <Icon name="checkin" size={16} />{mdBusy ? "Arbeite…" : "Stammdaten importieren"}
+            </button>
+          </form>
+        </div>
+        {mdInfo && <p className="muted small">{mdInfo}</p>}
+      </section>
+
       <section className="card">
         <div className="card-head"><Icon name="tag" /><h2>QR-Etiketten-Export (P-touch &amp; Co.)</h2></div>
         <p className="muted small mt-0">