Invoice Management System Documentation

# Invoice Management System - Documentation

## Overview

The Invoice Management System is a web-based application designed to simplify billing, manage customers and vendors, generate GST-compliant invoices, track payments, and provide in-depth business analytics. It is ideal for SMEs, traders, service providers, and professionals.

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## Key Features

### 1. **Dashboard**

* Real-time business overview
* Total invoices, revenue, pending dues, and expenses
* Graphs for monthly trends

### 2. **Client / Customer Management**

* Add/Edit/Delete customers
* Store billing & shipping address, GSTIN, email, and phone
* View client-wise invoice and payment history

### 3. **Vendor / Supplier Management**

* Add/Edit/Delete vendors
* Link purchase bills to vendors
* Track payments and credits

### 4. **Item Management**

* Add/Edit/Delete products or services
* Set tax %, unit, HSN/SAC code, default price
* Inventory tracking (optional)

### 5. **Invoices**

* Create multi-item GST invoices
* Auto calculation of tax, discounts, and totals
* Invoice preview, print, email, and PDF
* Status tracking: Paid / Unpaid / Partial

### 6. **Quotations**

* Generate and send quotes
* Convert quotation to invoice
* Track quote acceptance and status

### 7. **Delivery Challan**

* Generate challans for goods delivery
* Convert to invoice once goods are billed
* Track delivery status

### 8. **Credit Note & Debit Note**

* Issue notes linked to invoices
* GST compliant
* Adjustment against future invoices

### 9. **Purchase Orders (PO)**

* Create and send purchase orders to vendors
* Convert PO to purchase bill
* Track PO status

### 10. **Purchase Bills**

* Record vendor bills
* Calculate GST input credit
* Track due payments

### 11. **Expenses**

* Record business expenses by category
* Upload receipts
* Tax and non-tax entries

### 12. **Reports**

* Sales, Purchase, Tax, Profit & Loss
* Exportable PDF/Excel reports
* GSTR-compatible tax summaries

### 13. **Preferences**

* Configure company details, logo, GSTIN
* Set invoice format, numbering logic
* Enable/Disable modules

### 14. **Admin Panel**

* Dashboard analytics
* User Management:

* Add/Edit/Delete Users
* Enable/Disable Users
* Reset Password / See Password
* View user's Invoices & Clients
* Export user-related data
* Role-Based Permissions
* Backup & Restore
* Audit Logs

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## Security

* Role-based Access Control (RBAC)
* Encrypted password storage
* Login/session timeout
* Admin-only access for sensitive features

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## Technology Stack

* Frontend: HTML, React.js, Tailwind CSS
* Backend: Node.js / PHP / Python (flexible)
* Database: MySQL / MongoDB
* PDF: jsPDF / Puppeteer / PDFMake

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## Export Options

* Invoice PDF / Excel
* Reports: Sales, Tax, Client
* Backup All Data (zip/csv)
* Per-user Export
* UPI / Payment Gateway Tracking
* Recurring Invoice Automation
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