diff --git a/application/account_facts_readonly.py b/application/account_facts_readonly.py
index bcb2907..31a74a0 100644
--- a/application/account_facts_readonly.py
+++ b/application/account_facts_readonly.py
@@ -179,12 +179,14 @@ def collect_firstrade_account_facts(
         raise AccountFactsUnavailable("observation_time_invalid") from None
     try:
         accounts = client.account_numbers()
-        if (
-            not isinstance(accounts, list)
-            or any(not isinstance(account, str) or not account for account in accounts)
-            or accounts.count(expected) != 1
+        if not isinstance(accounts, list) or any(
+            not isinstance(account, str) or not account for account in accounts
         ):
             raise AccountFactsUnavailable("account_identity_mismatch")
+        if not accounts:
+            raise AccountFactsUnavailable("account_list_empty")
+        if accounts.count(expected) != 1:
+            raise AccountFactsUnavailable("account_identity_mismatch")
         selected_account = client.select_account(expected)
         if selected_account != expected:
             raise AccountFactsUnavailable("account_identity_mismatch")
diff --git a/application/firstrade_client.py b/application/firstrade_client.py
index f899759..5c35f04 100644
--- a/application/firstrade_client.py
+++ b/application/firstrade_client.py
@@ -130,6 +130,24 @@ def mask_account_id(account_id: str) -> str:
         return "*" * len(value)
     return f"{'*' * max(0, len(value) - 4)}{value[-4:]}"
 
+def normalize_account_number(value: object) -> str | None:
+    """Coerce Firstrade account identifiers to comparable non-empty strings."""
+    if value is None or isinstance(value, bool):
+        return None
+    if isinstance(value, int):
+        text = str(value)
+    elif isinstance(value, float):
+        if not value.is_integer():
+            return None
+        text = str(int(value))
+    elif isinstance(value, str):
+        text = value.strip()
+    else:
+        return None
+    return text or None
+
+
+
 
 def _coerce_positive_float(value: float | None, field: str) -> float | None:
     if value is None:
@@ -472,16 +490,22 @@ def require_connected(self) -> tuple[Any, Any]:
 
     def account_numbers(self) -> list[str]:
         _, account_data = self.require_connected()
-        return list(getattr(account_data, "account_numbers", []))
+        normalized: list[str] = []
+        for item in list(getattr(account_data, "account_numbers", []) or []):
+            account = normalize_account_number(item)
+            if account is not None:
+                normalized.append(account)
+        return normalized
 
     def select_account(self, requested_account: str | None = None) -> str:
         accounts = self.account_numbers()
         if requested_account:
-            if requested_account not in accounts:
+            wanted = normalize_account_number(requested_account)
+            if wanted is None or wanted not in accounts:
                 raise FirstradePlatformError(
-                    f"Requested account {mask_account_id(requested_account)} was not returned by Firstrade."
+                    f"Requested account {mask_account_id(str(requested_account or ''))} was not returned by Firstrade."
                 )
-            return requested_account
+            return wanted
         if len(accounts) == 1:
             return accounts[0]
         if not accounts:
@@ -504,7 +528,11 @@ def list_account_summaries(self) -> list[dict[str, Any]]:
     def get_balances(self, account: str) -> dict[str, Any]:
         _, account_data = self.require_connected()
         balances = dict(account_data.get_account_balances(account))
-        account_balances = dict(getattr(account_data, "account_balances", {}) or {})
+        account_balances = {
+            key: value
+            for raw_key, value in dict(getattr(account_data, "account_balances", {}) or {}).items()
+            if (key := normalize_account_number(raw_key)) is not None
+        }
         account_list_total_value = account_balances.get(account)
         if account_list_total_value is not None and "account_list_total_value" not in balances:
             balances["account_list_total_value"] = account_list_total_value
diff --git a/main.py b/main.py
index d7773ed..5ead27a 100644
--- a/main.py
+++ b/main.py
@@ -939,7 +939,11 @@ def account_facts_sync():
             account_scope=str(runtime_target.account_scope),
         )
     except AccountFactsUnavailable as exc:
-        app.logger.warning("account_facts_sync collect failed reason=%s", exc.reason_code)
+        app.logger.warning(
+            "account_facts_sync collect failed reason=%s expected=%s",
+            exc.reason_code,
+            mask_account_id(config.account_id or ""),
+        )
         return jsonify({"ok": False, "error": exc.reason_code}), 503
     except AccountFactsPublishError as exc:
         app.logger.warning("account_facts_sync build failed reason=%s", exc.reason_code)
diff --git a/tests/test_firstrade_client.py b/tests/test_firstrade_client.py
index fe0f162..2bba942 100644
--- a/tests/test_firstrade_client.py
+++ b/tests/test_firstrade_client.py
@@ -536,3 +536,24 @@ def env(name, default=None):
     assert credentials.username == "synthetic-user"
     assert credentials.password == credentials.mfa_secret == credentials.mfa_code == ""
     assert reads == ["firstrade-username"]
+
+
+def test_account_numbers_coerces_int_ids_for_selector_match():
+    class IntAccountData(FakeAccountData):
+        account_numbers = [12345678]
+        account_balances = {12345678: "100.00"}
+
+        def get_account_balances(self, account):
+            return {"account": account, "total_value": "100.00"}
+
+    credentials = FirstradeCredentials(username="user", password="pass")
+    client = FirstradeBrokerClient(
+        credentials,
+        session_factory=FakeSession,
+        account_data_factory=IntAccountData,
+        order_factory=FakeOrder,
+    ).connect()
+    assert client.account_numbers() == ["12345678"]
+    assert client.select_account("12345678") == "12345678"
+    balances = client.get_balances("12345678")
+    assert balances["account_list_total_value"] == "100.00"