diff --git a/pyproject.toml b/pyproject.toml
index acf0214..92a8d49 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "bluefin_v2_client"
-version = "2.3.1"
+version = "2.4.0"
 description = "Library to interact with Bluefin exchange protocol including its off-chain api-gateway and on-chain contracts"
 readme = "README.md"
 requires-python = ">=3.8"
diff --git a/src/bluefin_v2_client/client.py b/src/bluefin_v2_client/client.py
index f37de47..9c9272f 100644
--- a/src/bluefin_v2_client/client.py
+++ b/src/bluefin_v2_client/client.py
@@ -325,16 +325,18 @@ async def post_signed_order(self, params: PlaceOrderRequest):
         )
 
     ## Contract calls
-    async def deposit_margin_to_bank(self, amount: int, coin_id: str) -> bool:
+    async def deposit_margin_to_bank(self, amount: int, coin_id: str = "") -> bool:
         """
         Deposits given amount of USDC from user's account to margin bank
 
         Inputs:
             amount (number): quantity of usdc to be deposited to bank in base decimals (1,2 etc)
-
+            coin_id (string) (optional): the id of the coin you want the amount to be deducted from
         Returns:
             Boolean: true if amount is successfully deposited, false otherwise
         """
+        if coin_id == "":
+            coin_id = await self._get_coin_having_balance(amount)
         package_id = self.contracts.get_package_id()
         user_address = self.account.getUserAddress()
         callArgs = []
@@ -585,7 +587,7 @@ async def get_native_chain_token_balance(self) -> float:
         except Exception as e:
             raise (Exception(f"Failed to get balance, error: {e}"))
 
-    def get_usdc_coins(self):
+    async def get_usdc_coins(self):
         """
         Returns the list of the usdc coins owned by user
         """
@@ -609,7 +611,7 @@ async def get_usdc_balance(self) -> float:
             result = rpc_call_sui_function(
                 self.url, callArgs, method="suix_getBalance"
             )["totalBalance"]
-            return fromSuiBase(result)
+            return fromUsdcBase(result)
 
         except Exception as e:
             raise (Exception("Failed to get balance, Exception: {}".format(e)))
@@ -628,7 +630,7 @@ async def get_margin_bank_balance(self) -> float:
                 self.url, call_args, method="suix_getDynamicFieldObject"
             )
 
-            balance = from1e18(
+            balance = fromSuiBase(
                 result["data"]["content"]["fields"]["value"]["fields"]["balance"]
             )
             return balance
@@ -950,6 +952,17 @@ async def reset_cancel_on_disconnect_timer(self, params: PostTimerAttributes):
             )
         return response
 
+    async def _get_coin_having_balance(self, balance: int) -> str:
+        usdc_coins_resp = await self.get_usdc_coins()
+        usdc_coins = usdc_coins_resp["data"]
+        balance = toSuiBase(balance)
+        for coin in usdc_coins:
+            if int(coin["balance"]) <= balance:
+                return coin["coinObjectId"]
+        raise Exception(
+            "Insufficient balance, please add more SUI tokens or merge your existing tokens"
+        )
+
     async def close_connections(self):
         # close aio http connection
         await self.apis.close_session()
diff --git a/src/bluefin_v2_client/utilities.py b/src/bluefin_v2_client/utilities.py
index fcb59bd..42c0286 100644
--- a/src/bluefin_v2_client/utilities.py
+++ b/src/bluefin_v2_client/utilities.py
@@ -30,6 +30,12 @@ def fromSuiBase(number: Union[str, int]) -> float:
     return number / float(BASE_1E9)
 
 
+def toSuiBase(number: Union[str, int]) -> int:
+    """Takes in a number and multiplies it by 1e9"""
+    number = int(number)
+    return number * BASE_1E9
+
+
 def toUsdcBase(number: Union[int, float]) -> int:
     """Converts a number to usdc contract onchain representation i.e. multiply it by 1e6"""
     return int(number * BASE_1E6)