diff --git a/backend/database_handler/accounts_manager.py b/backend/database_handler/accounts_manager.py
index ee34a69ec..bd02ef034 100644
--- a/backend/database_handler/accounts_manager.py
+++ b/backend/database_handler/accounts_manager.py
@@ -75,12 +75,19 @@ def create_new_account_with_address(
     def is_valid_address(self, address: str) -> bool:
         return is_address(address)
 
-    def get_account(self, account_address: str) -> CurrentState | None:
-        """Private method to retrieve an account from the data base"""
+    @staticmethod
+    def _normalize_address(account_address: str) -> str:
+        """Normalize to the checksum form used as the primary key, matching
+        get_account()/create_new_account_with_address(). Falls back to the
+        original value if checksumming fails."""
         try:
-            normalized = to_checksum_address(account_address)
+            return to_checksum_address(account_address)
         except Exception:
-            normalized = account_address
+            return account_address
+
+    def get_account(self, account_address: str) -> CurrentState | None:
+        """Private method to retrieve an account from the data base"""
+        normalized = self._normalize_address(account_address)
         account = (
             self.session.query(CurrentState)
             .filter(CurrentState.id == normalized)
@@ -114,16 +121,12 @@ def debit_account_balance(self, account_address: str, amount: int) -> bool:
         """Atomic conditional debit. Returns False if insufficient balance."""
         if amount <= 0:
             return True
-        try:
-            account_address = to_checksum_address(account_address)
-        except Exception:
-            pass
         result = self.session.execute(
             text(
                 "UPDATE current_state SET balance = balance - :amount "
                 "WHERE id = :addr AND balance >= :amount"
             ),
-            {"amount": amount, "addr": account_address},
+            {"amount": amount, "addr": self._normalize_address(account_address)},
         )
         return result.rowcount > 0
 
@@ -131,10 +134,7 @@ def credit_account_balance(self, account_address: str, amount: int):
         """Atomic credit. Creates account if it doesn't exist."""
         if amount <= 0:
             return
-        try:
-            account_address = to_checksum_address(account_address)
-        except Exception:
-            pass
+        account_address = self._normalize_address(account_address)
         self.session.execute(
             text(
                 "INSERT INTO current_state (id, data, balance) "
@@ -158,6 +158,7 @@ def credit_tx_value_once(
         Sets value_credited=true atomically. Returns True if credit was applied."""
         if amount <= 0:
             return False
+        target_address = self._normalize_address(target_address)
         # Ensure target account exists
         self.session.execute(
             text(
diff --git a/tests/unit/test_accounts_manager_normalization.py b/tests/unit/test_accounts_manager_normalization.py
new file mode 100644
index 000000000..b7678b45b
--- /dev/null
+++ b/tests/unit/test_accounts_manager_normalization.py
@@ -0,0 +1,77 @@
+"""Unit tests for AccountsManager address normalization in raw-SQL paths.
+
+debit_account_balance / credit_account_balance / credit_tx_value_once use
+raw SQL and previously received the address verbatim, while ORM paths
+(get_account / create_new_account_with_address) store rows keyed by
+to_checksum_address(). A lowercase address therefore created a duplicate
+account row and split balances. These tests exercise the fix with a mocked
+SQLAlchemy session — no database required.
+"""
+
+from unittest.mock import MagicMock
+
+from eth_utils import to_checksum_address
+
+from backend.database_handler.accounts_manager import AccountsManager
+
+RAW_ADDRESS = "0x71c7656ec7ab88b098defb751b7401b5f6d8976f"  # lowercase on purpose
+CHECKSUMMED = to_checksum_address(RAW_ADDRESS)
+assert RAW_ADDRESS != CHECKSUMMED  # fixture sanity: casing must differ
+
+
+def _executed_params(session: MagicMock) -> list[dict]:
+    return [call.args[1] for call in session.execute.call_args_list]
+
+
+def test_debit_normalizes_address():
+    session = MagicMock()
+    session.execute.return_value = MagicMock(rowcount=1)
+    assert AccountsManager(session).debit_account_balance(RAW_ADDRESS, 5) is True
+
+    (params,) = [p for p in _executed_params(session) if p.get("addr")]
+    assert params["addr"] == CHECKSUMMED
+
+
+def test_credit_normalizes_address_before_insert_and_update():
+    session = MagicMock()
+    AccountsManager(session).credit_account_balance(RAW_ADDRESS, 7)
+
+    params = [p for p in _executed_params(session) if p.get("addr")]
+    assert len(params) == 2  # INSERT ... ON CONFLICT + UPDATE
+    assert all(p["addr"] == CHECKSUMMED for p in params)
+
+
+def test_credit_tx_value_once_normalizes_target():
+    session = MagicMock()
+    # value_credited update must match so the credit path is taken
+    session.execute.return_value = MagicMock(rowcount=1)
+
+    manager = AccountsManager(session)
+    trx = manager.credit_tx_value_once("0x12" + "34" * 16, RAW_ADDRESS, 3)
+
+    assert trx is True
+    params = [p for p in _executed_params(session) if p.get("addr")]
+    assert params
+    assert all(p["addr"] == CHECKSUMMED for p in params)
+
+
+def test_credit_zero_or_negative_amount_is_noop():
+    session = MagicMock()
+    manager = AccountsManager(session)
+
+    manager.credit_account_balance(RAW_ADDRESS, 0)
+    manager.credit_account_balance(RAW_ADDRESS, -10)
+    assert manager.debit_account_balance(RAW_ADDRESS, 0) is True
+
+    session.execute.assert_not_called()
+
+
+def test_normalize_fallback_keeps_original():
+    """A value that to_checksum_address rejects must be used unchanged,
+    preserving the pre-existing behavior for non-address identifiers."""
+    session = MagicMock()
+    session.execute.return_value = MagicMock(rowcount=1)
+    AccountsManager(session).debit_account_balance("not-an-address", 5)
+
+    (params,) = [p for p in _executed_params(session) if p.get("addr")]
+    assert params["addr"] == "not-an-address"