FluxInvoice - Invoice Billing Management System

FluxInvoice is a clean, modern invoice and billing management system built with plain PHP 8 and MySQL - no frameworks, no Composer, no command line. It installs on any shared hosting in under 5 minutes with a step-by-step setup wizard.

Create professional invoices with multiple line items, tax and discounts, download them as beautiful PDF documents with your own logo, and track paid, unpaid and overdue invoices from a modern dashboard with revenue charts.

Perfect for freelancers, agencies and small businesses that want a simple self-hosted invoicing tool, or for developers who want a solid, well-commented codebase to build on.

Requirements: PHP 8.0 - 8.2, MySQL 5.7+ / MariaDB. Works on any shared hosting (cPanel etc.) - no VPS needed.

What you get: full well-commented source code, step-by-step HTML documentation, browser-based setup wizard plus manual installation guide.

Demo login - Email: demo@codeflux.me / Password: demo1234

Features

1. Professional PDF invoices with your logo (Dompdf bundled, nothing to install)
2. Dynamic invoice builder - unlimited line items, live totals, tax % and discounts
3. Status tracking - Paid / Unpaid / Overdue badges with automatic overdue detection
4. Dashboard with revenue statistics, outstanding amounts and 6-month revenue chart
5. Client management - add, edit, search and manage clients
6. Full branding - upload logo, set company details, any currency symbol, default tax rate
7. Re-theme the entire app by editing two CSS variables
8. 5-minute browser-based setup wizard with requirements check
9. Security built in - prepared statements, CSRF protection, bcrypt passwords, login lockout
10. Fully responsive - desktop, tablet and mobile
11. Well-commented code and complete HTML documentation
12. 12 months of included support

Requirements

1. PHP 8.0, 8.1 or 8.2
2. MySQL 5.7+ or MariaDB
3. PDO MySQL extension (enabled on virtually all hosting)
4. GD extension (for the logo on PDF invoices - standard on all hosting)

Works on any shared hosting (cPanel, Plesk, etc.) - no VPS, no Composer, no command line needed

Instructions

1. Upload the fluxinvoice folder contents to your web hosting (e.g. public_html) 2. Create an empty MySQL database in your hosting control panel 3. Open your website in a browser - the setup wizard starts automatically 4. The wizard checks requirements, connects your database and creates your admin account 5. Delete the /install folder when the wizard tells you to 6. Log in and set your company name, logo, currency and tax rate under Settings

Full step-by-step documentation with screenshots of every step is included in the download (documentation.html), including a manual installation method as fallback.