diff --git a/README.md b/README.md
index 42b3789..ce516b1 100644
--- a/README.md
+++ b/README.md
@@ -24,6 +24,8 @@ and test suites. New code coming in regularly.
   toggle ping->pong, and only one other address is authorized to toggle
   pong->ping. _Checking sender address_, _Comparing sender address with another
   arbitrary address_
+- **Bank** : A simple contract can receive coins, and store them into a cell.
+  _receive TON_, _store TON in a smart contract_
 
 ```sh
 yarn
@@ -47,4 +49,7 @@ yarn test tests/PingPong.spec.ts
 
 # Only test ping pong 2
 yarn test tests/PingPong2.spec.ts
+
+# Only test bank
+yarn test tests/Bank.spec.ts
 ```
diff --git a/contracts/bank.fc b/contracts/bank.fc
index 4a87f8a..5b0676b 100644
--- a/contracts/bank.fc
+++ b/contracts/bank.fc
@@ -1,56 +1,52 @@
 #include "imports/stdlib.fc";
 
 ;; storage variables
-global int ctx_balance;
+global cell ctx_balance;
 
 () load_data() impure {
-    var ds = get_data().begin_parse();
-    ctx_balance = ds~load_uint(32);
-    ds.end_parse();
+  var ds = get_data().begin_parse();
+  ctx_balance = ds~load_ref();
+  ds.end_parse();
 }
 
-() save_data() impure {
-    set_data(
+() save_data(int coins) impure {
+  set_data(
+    begin_cell()
+      .store_ref(
         begin_cell()
-            .store_uint(ctx_balance, 32)
-            .end_cell()
-    );
+          .store_coins(coins)
+          .end_cell()
+      )
+      .end_cell()
+  );
 }
 
 () recv_internal(int my_balance, int msg_value, cell in_msg_full, slice in_msg_body) impure {
-    if (in_msg_body.slice_empty?()) {
-        return ();
-    }
-
-    slice cs = in_msg_full.begin_parse();
-    int flags = cs~load_uint(4);
-    if (flags & 1) { 
-        return ();
-    }
-
-    load_data();
-    ~strdump("balance");
-    ~dump(ctx_balance);
-
-    int coins_amount = in_msg_body~load_coins();
-    ~strdump("coins_amount");
-    ~dump(coins_amount);
-
-    if (coins_amount != 0) {
-      ~strdump("not zero");
-      ctx_balance += coins_amount;
-      ~strdump("newbalance");
-      ~dump(ctx_balance);
-      save_data();
-      return ();
-    }
-  
-    load_data();
+  if (in_msg_body.slice_empty?()) {
+    return ();
+  }
+
+  slice cs = in_msg_full.begin_parse();
+  int flags = cs~load_uint(4);
+  if (flags & 1) { 
+    return ();
+  }
 
+  load_data();
+  slice current = ctx_balance.begin_parse();
+  (_, int current_balance) = current.load_coins();
+
+  int coins_amount = in_msg_body~load_coins();
+
+  if (coins_amount != 0) {
+    save_data(coins_amount + current_balance);
     return ();
+  }
+
+  throw(0xffff);
 }
 
-int get_bal() method_id {
-    load_data();
-    return ctx_balance;
+cell get_bal() method_id {
+  load_data();
+  return ctx_balance;
 }
diff --git a/tests/Bank.spec.ts b/tests/Bank.spec.ts
index b1f40c0..d66cde2 100644
--- a/tests/Bank.spec.ts
+++ b/tests/Bank.spec.ts
@@ -1,6 +1,6 @@
 import { Blockchain, SandboxContract, TreasuryContract } from '@ton/sandbox';
 import '@ton/test-utils';
-import { Cell, toNano, ContractProvider } from '@ton/core';
+import { Cell, toNano } from '@ton/core';
 import { compile } from '@ton/blueprint';
 
 import { Bank } from '../wrappers/Bank';
@@ -19,38 +19,40 @@ describe('[Bank]', () => {
     code = await compile('Bank');
     blockchain = await Blockchain.create();
     user1 = await blockchain.treasury('user1');
-    bankContract = blockchain.openContract(
-      Bank.createFromConfig({ balance: 0 }, code)
-    );
-    for (let i = 0; i < 3; i += 1) {
+    bankContract = blockchain.openContract(Bank.createFromConfig(code));
+    for (let i = 0; i < 10; i += 1) {
       transfers.push({
         sender: user1 as unknown as SandboxContract<TreasuryContract>,
-        coins: toNano(BigInt(Math.round(Math.random() * 100))),
+        coins: BigInt(Math.round(Math.random() * 100)),
       });
     }
+    /*
+      smart contract balance goes
+      above the 1B limit
+    */
+    transfers.push({
+      sender: user1 as unknown as SandboxContract<TreasuryContract>,
+      coins: BigInt('1000000000'),
+    });
   });
 
   it('[Bank] user1 transfers to smart contract', async () => {
-    const deployResult = await bankContract.sendDeploy(
+    await bankContract.sendDeploy(
       (user1 as SandboxContract<TreasuryContract>).getSender(),
       toNano('0.05')
     );
-    let i = 1;
+    let bi = 0n;
     for (const transfer of transfers) {
-      console.log('transfer.coins');
-      console.log(transfer.coins);
-      /* const balance = await bankContract.getBalance();
-      console.log('balance', balance); */
-      const bal = await bankContract.getBal();
-      console.log('bal', bal);
-      const a = await bankContract.sendTransfer(
+      bi += transfer.coins;
+      await bankContract.sendTransfer(
         (user1 as SandboxContract<TreasuryContract>).getSender(),
         {
           value: toNano('0.05'),
           coins: transfer.coins,
         }
       );
-      expect(true).toBe(true);
+      const bal = await bankContract.getBal();
+      expect(bal).toBe(bi);
     }
   });
 });
diff --git a/wrappers/Bank.ts b/wrappers/Bank.ts
index c4d163c..c37e93e 100644
--- a/wrappers/Bank.ts
+++ b/wrappers/Bank.ts
@@ -10,12 +10,10 @@ import {
   toNano,
 } from '@ton/core';
 
-export type BankConfig = {
-  balance: number;
-};
-
-export function bankConfigToCell(config: BankConfig): Cell {
-  return beginCell().storeUint(config.balance, 32).endCell();
+export function bankConfigToCell(): Cell {
+  return beginCell()
+    .storeRef(beginCell().storeCoins(toNano('0')).endCell())
+    .endCell();
 }
 
 export class Bank implements Contract {
@@ -28,8 +26,8 @@ export class Bank implements Contract {
     return new Bank(address);
   }
 
-  static createFromConfig(config: BankConfig, code: Cell, workchain = 0) {
-    const data = bankConfigToCell(config);
+  static createFromConfig(Cell, workchain = 0) {
+    const data = bankConfigToCell();
     const init = { code, data };
     return new Bank(contractAddress(workchain, init), init);
   }
@@ -62,11 +60,6 @@ export class Bank implements Contract {
 
   async getBal(provider: ContractProvider) {
     const result = await provider.get('get_bal', []);
-    return result.stack.readNumber();
-  }
-
-  async getBalance(provider: ContractProvider) {
-    const result = await provider.get('get_balance', []);
-    return result.stack.readNumber();
+    return result.stack.readCell().beginParse().preloadCoins();
   }
 }