Vb.net Billing Software Source Code -

Public Class frmMain
    Private Sub btnBilling_Click(sender As Object, e As EventArgs) Handles btnBilling.Click
        Dim billing As New frmBilling()
        billing.ShowDialog()
    End Sub
Private Sub btnProducts_Click(sender As Object, e As EventArgs) Handles btnProducts.Click
    Dim products As New frmProducts()
    products.ShowDialog()
End Sub
Private Sub btnCustomers_Click(sender As Object, e As EventArgs) Handles btnCustomers.Click
    Dim customers As New frmCustomers()
    customers.ShowDialog()
End Sub
Private Sub btnReports_Click(sender As Object, e As EventArgs) Handles btnReports.Click
    Dim reports As New frmReports()
    reports.ShowDialog()
End Sub
Private Sub frmMain_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    lblUser.Text = "Welcome, " & Environment.UserName
    lblDateTime.Text = DateTime.Now.ToString()
' Timer for real-time clock
    Timer1.Start()
End Sub
Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
    lblDateTime.Text = DateTime.Now.ToString()
End Sub

End Class

In frm_Billing.vb, a DataGridView acts as the cart. The user scans a barcode or selects a product, and it is added to the cart.

Private Sub AddProductToCart(productID As Integer, qty As Integer)
    'Fetch product details from database using productID
    Dim query As String = "SELECT ProductName, SellingPrice, GST_Percent FROM tbl_Products WHERE ProductID = " & productID
    Using conn As SqlConnection = getConnection()
        conn.Open()
        Using cmd As New SqlCommand(query, conn)
            Dim reader As SqlDataReader = cmd.ExecuteReader()
            If reader.Read() Then
                Dim productName As String = reader("ProductName").ToString()
                Dim price As Decimal = Convert.ToDecimal(reader("SellingPrice"))
                Dim gstPercent As Integer = Convert.ToInt32(reader("GST_Percent"))
            'Add row to DataGridView (dgvCart)
            dgvCart.Rows.Add(productID, productName, qty, price, qty * price, gstPercent)
            CalculateTotal() 'Update subtotal, tax, grand total
        End If
    End Using
End Using

End Sub
Private Sub CalculateTotal()
Dim subTotal As Decimal = 0
For Each row As DataGridViewRow In dgvCart.Rows
subTotal += Convert.ToDecimal(row.Cells("Total").Value)
Next
'Assuming GST is calculated on SubTotal (simplified)
Dim gstAmount As Decimal = (subTotal * 18) / 100 '18% GST
Dim grandTotal As Decimal = subTotal + gstAmount
lblSubTotal.Text = subTotal.ToString("C") 'C = Currency format
lblTax.Text = gstAmount.ToString("C")
lblGrandTotal.Text = grandTotal.ToString("C")

End Sub

Are you tired of the monthly subscription fees of QuickBooks? Frustrated that your current invoicing software doesn’t quite fit your specific business workflow?

Every business owner reaches a breaking point where they think, "I could build this myself." If you are a developer or a tech-savvy entrepreneur, diving into VB.NET billing software source code might be the best business decision you make this year.

In this post, we’re going to explore why legacy tech isn’t dead, where to find the right source code, and how customizing your own billing engine can save you thousands of dollars.

If you go hunting for source code on platforms like CodeProject, GitHub, or CodeCanyon, don’t just download the first zip file you see. Look for these critical features to ensure the code is modern and maintainable:

1. 3-Tier Architecture Ensure the code separates the logic. You want a Data Access Layer (DAL), a Business Logic Layer (BLL), and a Presentation Layer. This makes it easier to update the UI without breaking the database calculations.

2. SQL Server Backend While Access databases are common in older VB projects, you want a source code that utilizes Microsoft SQL Server. It handles large volumes of transactions and ensures your data integrity—crucial for financial records. vb.net billing software source code

3. Clean Reporting Tools The heart of billing software is the report. Look for projects using RDLC (Report Definition Language Client) or Crystal Reports. If the source code includes a "Drag and Drop" report designer, that’s a huge bonus.

Private Sub btnAddProduct_Click(sender As Object, e As EventArgs) Handles btnAddProduct.Click
    Try
        OpenDB()
        Dim query As String = "INSERT INTO tbl_Product (ProductCode, ProductName, Unit, SellingPrice, GST_Percent, StockQuantity) 
                               VALUES (@code, @name, @unit, @price, @gst, @stock)"
        cmd = New SqlCommand(query, conn)
        cmd.Parameters.AddWithValue("@code", txtCode.Text)
        cmd.Parameters.AddWithValue("@name", txtName.Text)
        cmd.Parameters.AddWithValue("@unit", cmbUnit.Text)
        cmd.Parameters.AddWithValue("@price", Convert.ToDecimal(txtPrice.Text))
        cmd.Parameters.AddWithValue("@gst", Convert.ToDecimal(txtGST.Text))
        cmd.Parameters.AddWithValue("@stock", Convert.ToDecimal(txtStock.Text))
        cmd.ExecuteNonQuery()
        MessageBox.Show("Product saved successfully.")
        LoadProductsDataGrid()
    Catch ex As Exception
        MessageBox.Show("Error: " & ex.Message)
    Finally
        CloseDB()
    End Try
End Sub

-- Create Database
CREATE DATABASE BillingSystem;
GO
USE BillingSystem;
GO
-- Products Table
CREATE TABLE Products (
ProductID INT PRIMARY KEY IDENTITY(1,1),
ProductCode NVARCHAR(50) UNIQUE NOT NULL,
ProductName NVARCHAR(100) NOT NULL,
Category NVARCHAR(50),
UnitPrice DECIMAL(10,2) NOT NULL,
StockQuantity INT NOT NULL DEFAULT 0,
GSTPercentage DECIMAL(5,2) DEFAULT 0,
CreatedDate DATETIME DEFAULT GETDATE()
);
-- Customers Table
CREATE TABLE Customers (
CustomerID INT PRIMARY KEY IDENTITY(1,1),
CustomerName NVARCHAR(100) NOT NULL,
PhoneNumber NVARCHAR(15),
Email NVARCHAR(100),
Address NVARCHAR(255),
CreatedDate DATETIME DEFAULT GETDATE()
);
-- Invoices Table
CREATE TABLE Invoices (
InvoiceID INT PRIMARY KEY IDENTITY(1,1),
InvoiceNumber NVARCHAR(20) UNIQUE NOT NULL,
CustomerID INT FOREIGN KEY REFERENCES Customers(CustomerID),
InvoiceDate DATETIME DEFAULT GETDATE(),
SubTotal DECIMAL(10,2),
GSTAmount DECIMAL(10,2),
TotalAmount DECIMAL(10,2),
PaymentMethod NVARCHAR(50),
Status NVARCHAR(20) DEFAULT 'Pending'
);
-- Invoice Items Table
CREATE TABLE InvoiceItems (
ItemID INT PRIMARY KEY IDENTITY(1,1),
InvoiceID INT FOREIGN KEY REFERENCES Invoices(InvoiceID),
ProductID INT FOREIGN KEY REFERENCES Products(ProductID),
Quantity INT NOT NULL,
UnitPrice DECIMAL(10,2),
TotalPrice DECIMAL(10,2),
GSTAmount DECIMAL(10,2)
);
 End Class

VB.NET billing software source code offers a practical, customizable foundation for desktop invoicing systems. Whether you run a retail store, a wholesale distributor, or a service center, VB.NET gives you full control over your billing logic, tax calculations, and reporting—without recurring subscription fees.

Start with a clean database schema, implement the core billing loop, and then incrementally add features like printing, barcodes, and customer history. With the code examples provided above, you can build a production-ready billing system in weeks, not months.

Remember: the best source code is the one you understand and can modify. Download a working project, dissect its Form_Load, CalculateTotals, and SaveInvoice methods, and tailor it to your local tax laws and workflow.

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