diff --git a/backend/scripts/pruefe_transfers.py b/backend/scripts/pruefe_transfers.py
new file mode 100755
index 0000000..f5929fe
--- /dev/null
+++ b/backend/scripts/pruefe_transfers.py
@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+"""Zeigt, welches Konto an welches überträgt – und wo dabei etwas fehlt.
+
+Ein falscher Kontostand kommt selten von den Ausgaben, fast immer von den
+Überträgen: falsche Richtung, fehlendes Zielkonto oder ein Währungswechsel
+ohne Zielbetrag (dann wird der Fremdbetrag 1:1 gutgeschrieben).
+
+Aufruf:  pruefe_transfers.py [pfad-zur-db]
+"""
+import sqlite3
+import sys
+
+DB = sys.argv[1] if len(sys.argv) > 1 else "/var/lib/certain-finance/app.db"
+con = sqlite3.connect(f"file:{DB}?mode=ro", uri=True)
+con.row_factory = sqlite3.Row
+
+konten = {r["id"]: r for r in con.execute("SELECT id, name, currency FROM accounts")}
+
+
+def name(i):
+    return konten[i]["name"] if i in konten else f"?{i}"
+
+
+def waehrung(i):
+    return konten[i]["currency"] if i in konten else "?"
+
+
+def geld(c):
+    return f"{(c or 0) / 100:,.2f}".replace(",", "'")
+
+
+print(f"Datenbank: {DB}\n")
+print("=== Wer überträgt an wen ===")
+print(f"{'von':<24}{'nach':<24}{'Anz':>5}{'Summe raus':>14}{'Summe rein':>14}")
+print("-" * 81)
+for r in con.execute(
+    "SELECT account_id a, to_account_id b, COUNT(*) n, SUM(amount_cents) raus, "
+    "SUM(COALESCE(to_amount_cents, amount_cents)) rein FROM transactions "
+    "WHERE type='transfer' AND to_account_id IS NOT NULL GROUP BY a, b ORDER BY raus DESC"
+):
+    print(f"{name(r['a'])[:23]:<24}{name(r['b'])[:23]:<24}{r['n']:>5}"
+          f"{geld(r['raus']) + ' ' + waehrung(r['a']):>14}"
+          f"{geld(r['rein']) + ' ' + waehrung(r['b']):>14}")
+
+offen = con.execute(
+    "SELECT COUNT(*) n, SUM(amount_cents) s FROM transactions "
+    "WHERE type='transfer' AND to_account_id IS NULL").fetchone()
+print(f"\nÜberträge OHNE Zielkonto: {offen['n']}, Summe {geld(offen['s'])}"
+      "   <-- gehen vom Quellkonto ab und kommen nirgends an")
+
+print("\n=== Währungswechsel ohne Zielbetrag ===")
+schief = con.execute(
+    "SELECT t.id, t.date, t.amount_cents, COALESCE(t.payee,'') p, a.name qn, a.currency qw, "
+    "z.name zn, z.currency zw FROM transactions t "
+    "JOIN accounts a ON a.id = t.account_id JOIN accounts z ON z.id = t.to_account_id "
+    "WHERE t.type='transfer' AND a.currency <> z.currency AND t.to_amount_cents IS NULL "
+    "ORDER BY t.amount_cents DESC").fetchall()
+if not schief:
+    print("  keine – gut.")
+else:
+    summe = sum(r["amount_cents"] for r in schief)
+    print(f"  {len(schief)} Stück, Summe {geld(summe)}"
+          "   <-- der Betrag wird ohne Umrechnung gutgeschrieben")
+    for r in schief[:12]:
+        print(f"    {r['date']}  {geld(r['amount_cents']):>10} {r['qw']} -> {r['zw']}  "
+              f"{r['qn'][:16]:<16} -> {r['zn'][:16]:<16} {r['p'][:26]}")
+
+print("\n=== Die 12 grössten Überträge ===")
+for r in con.execute(
+    "SELECT t.date, t.amount_cents, t.to_amount_cents, COALESCE(t.payee,'') p, "
+    "t.account_id a, t.to_account_id b FROM transactions t WHERE t.type='transfer' "
+    "ORDER BY t.amount_cents DESC LIMIT 12"
+):
+    ziel = name(r["b"]) if r["b"] else "– kein Ziel –"
+    print(f"  {r['date']}  {geld(r['amount_cents']):>10} {waehrung(r['a'])}  "
+          f"{name(r['a'])[:18]:<18} -> {ziel[:18]:<18} {r['p'][:30]}")