diff --git a/src/EthSmartContractIO/Builders/DataBuilder.cs b/src/EthSmartContractIO/Builders/DataBuilder.cs
new file mode 100644
index 0000000..fbd750c
--- /dev/null
+++ b/src/EthSmartContractIO/Builders/DataBuilder.cs
@@ -0,0 +1,30 @@
+using System.Numerics;
+using Nethereum.Hex.HexTypes;
+using Net.Web3.EthereumWallet;
+using EthSmartContractIO.Extensions;
+
+namespace EthSmartContractIO.Builders;
+
+public class DataBuilder
+{
+    private string data;
+
+    public DataBuilder(string functionName)
+    {
+        data = functionName.ToMethodSignature();
+    }
+
+    public DataBuilder WithBigInteger(BigInteger parameter)
+    {
+        data += new HexBigInteger(parameter).HexValue[2..].PadLeft(64, '0');
+        return this;
+    }
+
+    public DataBuilder WithAddress(EthereumAddress parameter)
+    {
+        data += parameter.Address[2..].PadLeft(64, '0');
+        return this;
+    }
+
+    public string Build() => data;
+}
\ No newline at end of file
diff --git a/src/EthSmartContractIO/ContractIO/ContractIO.cs b/src/EthSmartContractIO/ContractIO/ContractIO.cs
index d77bde3..15d5f84 100644
--- a/src/EthSmartContractIO/ContractIO/ContractIO.cs
+++ b/src/EthSmartContractIO/ContractIO/ContractIO.cs
@@ -1,5 +1,4 @@
-using Nethereum.Util;
-using EthSmartContractIO.Models;
+using EthSmartContractIO.Models;
 
 namespace EthSmartContractIO.ContractIO;
 
@@ -34,9 +33,6 @@ public ContractIO(IServiceProvider? serviceProvider)
     public virtual string ExecuteAction(RpcRequest request) =>
         GetContractIO(request).RunContractAction();
 
-    public static string GetMethodHash(string methodSignature) =>
-        Sha3Keccack.Current.CalculateHash(methodSignature)[..8];
-
     /// <summary>
     /// Gets the appropriate <see cref="IContractIO"/> instance for the given request.
     /// </summary>
diff --git a/src/EthSmartContractIO/EthSmartContractIO.csproj b/src/EthSmartContractIO/EthSmartContractIO.csproj
index 06d0bb0..1bb4672 100644
--- a/src/EthSmartContractIO/EthSmartContractIO.csproj
+++ b/src/EthSmartContractIO/EthSmartContractIO.csproj
@@ -40,6 +40,7 @@
     <PackageReference Include="FluentValidation" Version="11.5.2" />
     <PackageReference Include="Flurl.Http" Version="3.2.4" />
     <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="7.0.0" />
+    <PackageReference Include="Net.Web3.EthereumWallet" Version="1.0.0" />
     <PackageReference Include="Nethereum.HdWallet" Version="4.14.0" />
     <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
   </ItemGroup>
diff --git a/src/EthSmartContractIO/Extensions/StringExtensions.cs b/src/EthSmartContractIO/Extensions/StringExtensions.cs
new file mode 100644
index 0000000..d4965d2
--- /dev/null
+++ b/src/EthSmartContractIO/Extensions/StringExtensions.cs
@@ -0,0 +1,9 @@
+using Nethereum.Util;
+
+namespace EthSmartContractIO.Extensions;
+
+public static class StringExtensions
+{
+    public static string ToMethodSignature(this string functionName) =>
+        "0x" + new Sha3Keccack().CalculateHash(functionName)[..8];
+}
\ No newline at end of file
diff --git a/tests/EthSmartContractIO.Tests/Builders/DataBuilderTests.cs b/tests/EthSmartContractIO.Tests/Builders/DataBuilderTests.cs
new file mode 100644
index 0000000..9698052
--- /dev/null
+++ b/tests/EthSmartContractIO.Tests/Builders/DataBuilderTests.cs
@@ -0,0 +1,63 @@
+using Xunit;
+using System.Numerics;
+using FluentAssertions;
+using Net.Web3.EthereumWallet;
+using EthSmartContractIO.Builders;
+using EthSmartContractIO.Extensions;
+
+namespace EthSmartContractIO.Tests.Builders;
+
+public class DataBuilderTests
+{
+    private const string methodName = "transfer(address,uint256)";
+    private readonly string methodSignature = methodName.ToMethodSignature();
+    private readonly BigInteger bigInt = new(12345);
+    private readonly EthereumAddress ethereumAddress = new("0x1234567890123456789012345678901234567890");
+    private readonly DataBuilder dataBuilder = new(methodName);
+
+    [Fact]
+    internal void Constructor_InitializesMethodSignatureCorrectly()
+    {
+        var result = dataBuilder.Build();
+
+        result.Should().StartWith(methodSignature);
+    }
+
+    [Fact]
+    internal void WithBigInteger_AppendsBigIntegerCorrectly()
+    {
+        var expected = bigInt.ToString("X").PadLeft(64, '0');
+
+        var result = dataBuilder.WithBigInteger(bigInt)
+            .Build();
+
+        result.Should().Contain(expected);
+    }
+
+    [Fact]
+    internal void WithAddress_AppendsEthereumAddressCorrectly()
+    {
+        var expected = ethereumAddress.Address[2..].PadLeft(64, '0');
+
+        var result = dataBuilder.WithAddress(ethereumAddress)
+            .Build();
+
+        result.Should().Contain(expected);
+    }
+
+    [Fact]
+    internal void Build_CreatesCorrectDataString()
+    {
+        var expectedBigInteger = bigInt.ToString("X").PadLeft(64, '0');
+        var expectedAddress = ethereumAddress.Address[2..].PadLeft(64, '0');
+
+        var expectedData = $"{methodSignature}{expectedAddress}{expectedBigInteger}";
+
+        var result = dataBuilder
+            .WithAddress(ethereumAddress)
+            .WithBigInteger(bigInt)
+            .Build();
+
+        result.Should().Be(expectedData);
+    }
+}
\ No newline at end of file
diff --git a/tests/EthSmartContractIO.Tests/ContractIO/ContractIOTests.cs b/tests/EthSmartContractIO.Tests/ContractIO/ContractIOTests.cs
index e808174..6779a40 100644
--- a/tests/EthSmartContractIO.Tests/ContractIO/ContractIOTests.cs
+++ b/tests/EthSmartContractIO.Tests/ContractIO/ContractIOTests.cs
@@ -2,15 +2,15 @@
 using Xunit;
 using Flurl.Http.Testing;
 using Newtonsoft.Json.Linq;
-using Nethereum.Hex.HexTypes;
 using Nethereum.RPC.Eth.DTOs;
+using Nethereum.Hex.HexTypes;
 using EthSmartContractIO.Gas;
 using EthSmartContractIO.Models;
 using EthSmartContractIO.Builders;
-using EthSmartContractIO.Tests.Mocks;
 using EthSmartContractIO.Transaction;
+using EthSmartContractIO.Tests.Mocks;
 
-namespace EthSmartContractIO.ContractIO.Tests;
+namespace EthSmartContractIO.Tests.ContractIO;
 
 public class ContractIOTests
 {
@@ -44,7 +44,7 @@ internal void ExecuteAction_Read_ExpectedJsonString()
             .ForCallsTo(RpcUrl)
             .RespondWithJson(response);
 
-        var result = new ContractIO().ExecuteAction(readRequest);
+        var result = new EthSmartContractIO.ContractIO.ContractIO().ExecuteAction(readRequest);
 
         Assert.NotNull(result);
         Assert.Equal(response["result"]?.ToString(), result);
@@ -68,7 +68,7 @@ internal void ExecuteAction_WriteWithMockServices_ExpectedTransactionHex()
             .AddTransactionSender(mockTransactionSender.Object)
             .Build();
 
-        var result = new ContractIO(serviceProvider).ExecuteAction(writeRequest);
+        var result = new EthSmartContractIO.ContractIO.ContractIO(serviceProvider).ExecuteAction(writeRequest);
 
         Assert.NotNull(result);
         Assert.Equal("transactionHash", result);
@@ -81,21 +81,9 @@ internal void ExecuteAction_WriteWithMockWeb3_ExpectedTransactionHex()
             .AddWeb3(MockWeb3.GetMock)
             .Build();
 
-        var result = new ContractIO(serviceProvider).ExecuteAction(writeRequest);
+        var result = new EthSmartContractIO.ContractIO.ContractIO(serviceProvider).ExecuteAction(writeRequest);
 
         Assert.NotNull(result);
         Assert.Equal("transactionHash", result);
     }
-
-    [Fact]
-    internal void GetMethodHash_TransferSignature_ExpectedHash()
-    {
-        const string methodSignature = "Transfer(address,address,uint256)";
-
-        const string transferSignature = "ddf252ad";
-
-        var actualValue = ContractIO.GetMethodHash(methodSignature);
-
-        Assert.Equal(transferSignature, actualValue);
-    }
 }
diff --git a/tests/EthSmartContractIO.Tests/EthSmartContractIO.Tests.csproj b/tests/EthSmartContractIO.Tests/EthSmartContractIO.Tests.csproj
index 72241f1..3cc4816 100644
--- a/tests/EthSmartContractIO.Tests/EthSmartContractIO.Tests.csproj
+++ b/tests/EthSmartContractIO.Tests/EthSmartContractIO.Tests.csproj
@@ -12,6 +12,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="FluentAssertions" Version="6.12.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.5.0" />
     <PackageReference Include="Moq" Version="4.18.4" />
     <PackageReference Include="xunit" Version="2.4.2" />