diff --git a/src/password_manager/config_manager.py b/src/password_manager/config_manager.py
index 5d9d620..7c02aae 100644
--- a/src/password_manager/config_manager.py
+++ b/src/password_manager/config_manager.py
@@ -44,6 +44,7 @@ class ConfigManager:
                 "pin_hash": "",
                 "password_hash": "",
                 "inactivity_timeout": INACTIVITY_TIMEOUT,
+                "additional_backup_path": "",
             }
         try:
             data = self.vault.load_config()
@@ -54,6 +55,7 @@ class ConfigManager:
             data.setdefault("pin_hash", "")
             data.setdefault("password_hash", "")
             data.setdefault("inactivity_timeout", INACTIVITY_TIMEOUT)
+            data.setdefault("additional_backup_path", "")
 
             # Migrate legacy hashed_password.enc if present and password_hash is missing
             legacy_file = self.fingerprint_dir / "hashed_password.enc"
@@ -130,3 +132,15 @@ class ConfigManager:
         """Retrieve the inactivity timeout setting in seconds."""
         config = self.load_config(require_pin=False)
         return float(config.get("inactivity_timeout", INACTIVITY_TIMEOUT))
+
+    def set_additional_backup_path(self, path: Optional[str]) -> None:
+        """Persist an optional additional backup path in the config."""
+        config = self.load_config(require_pin=False)
+        config["additional_backup_path"] = path or ""
+        self.save_config(config)
+
+    def get_additional_backup_path(self) -> Optional[str]:
+        """Retrieve the additional backup path if configured."""
+        config = self.load_config(require_pin=False)
+        value = config.get("additional_backup_path", "")
+        return value or None
diff --git a/src/tests/test_config_manager.py b/src/tests/test_config_manager.py
index 92f3f31..5be4603 100644
--- a/src/tests/test_config_manager.py
+++ b/src/tests/test_config_manager.py
@@ -22,6 +22,7 @@ def test_config_defaults_and_round_trip():
         assert cfg["relays"] == list(DEFAULT_RELAYS)
         assert cfg["pin_hash"] == ""
         assert cfg["password_hash"] == ""
+        assert cfg["additional_backup_path"] == ""
 
         cfg_mgr.set_pin("1234")
         cfg_mgr.set_relays(["wss://example.com"], require_pin=False)
@@ -111,3 +112,21 @@ def test_password_hash_migrates_from_file(tmp_path):
     (tmp_path / "hashed_password.enc").unlink()
     cfg2 = cfg_mgr.load_config(require_pin=False)
     assert cfg2["password_hash"] == hashed.decode()
+
+
+def test_additional_backup_path_round_trip():
+    with TemporaryDirectory() as tmpdir:
+        vault, enc_mgr = create_vault(Path(tmpdir), TEST_SEED, TEST_PASSWORD)
+        cfg_mgr = ConfigManager(vault, Path(tmpdir))
+
+        # default should be empty string
+        assert cfg_mgr.load_config(require_pin=False)["additional_backup_path"] == ""
+
+        cfg_mgr.set_additional_backup_path("/tmp/my_backups")
+        cfg = cfg_mgr.load_config(require_pin=False)
+        assert cfg["additional_backup_path"] == "/tmp/my_backups"
+        assert cfg_mgr.get_additional_backup_path() == "/tmp/my_backups"
+
+        cfg_mgr.set_additional_backup_path(None)
+        cfg2 = cfg_mgr.load_config(require_pin=False)
+        assert cfg2["additional_backup_path"] == ""