Software Source Code - Vb.net Billing

: Generate sales reports, inventory reports, customer statements, profit/loss statements, and transaction histories—often exportable to PDF, Excel, or printed directly.

"The lack of a layered architecture makes the application brittle. For example, if the database schema changes, modifications are required directly in the UI event handlers (e.g., BtnSave_Click ), violating the Open/Closed Principle."

-- 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() );

Private Sub GenerateInvoiceNumber() currentInvoiceNumber = "INV-" & DateTime.Now.ToString("yyyyMMdd") & "-" & DateTime.Now.ToString("HHmmss") txtInvoiceNo.Text = currentInvoiceNumber End Sub vb.net billing software source code

A fully functional billing application typically includes these modules:

or Microsoft Reporting Services (for generating invoices) 2. Database Schema (SQL Server)

Stores the itemized breakdown for each invoice (Many-to-One relationship with Invoices). DetailID (AutoNumber, Primary Key) InvoiceID (Number, Foreign Key) ProductID (Number, Foreign Key) Quantity (Number) UnitPrice (Currency) SubTotal (Currency) Designing the Windows Forms Interface Database Schema (SQL Server) Stores the itemized breakdown

Before coding, you need a structured database. Create a database named BillingDB and execute these queries:

Here are the most valuable VB.NET billing source code repositories available for learning and customization:

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 printDialog

Use libraries like iTextSharp to export the DataGridView content into a PDF invoice.

printDialog.Document = printDocument If printDialog.ShowDialog() = DialogResult.OK Then printDocument.Print() End If End Sub

Developing a billing system is one of the most common projects for VB.NET developers, and with good reason—it's the perfect way to master database integration, user interface design, and business logic implementation.