🎯 Project Overview

Developed a comprehensive billing and account management system for VoIP service providers. The platform handles multi-tenant billing, automated invoicing, payment processing, usage tracking, and customer self-service portals—all integrated seamlessly with Asterisk PBX for real-time usage data.

💼 Business Impact

Automated billing: Eliminated 40+ hours/month of manual invoice generation
Revenue recovery: Reduced billing errors and improved collections by 95%
Customer satisfaction: Self-service portal reduced support tickets by 60%
Scalability: Single system manages billing for 2,000+ active accounts
Financial clarity: Real-time revenue tracking and forecasting

🛠️ Technical Architecture

Core Technologies

Laravel 11 - Backend framework
PHP 8.2 - Core application logic
MySQL 8 - Primary database with master-slave replication
Redis - Caching and queue management
Stripe API - Payment processing
Vue.js 3 - Customer portal frontend
Laravel Cashier - Subscription management
Snappy PDF - Invoice generation

System Modules

✅ Multi-Tenant Account Management

Isolated billing per organization/reseller
Hierarchical account structure (resellers → sub-accounts)
Custom pricing plans per tenant
Credit limits and prepaid balance tracking

✅ Usage Rating & Billing

Real-time CDR (Call Detail Record) import from Asterisk
Complex rating engine (per-second, per-minute, tiered pricing)
Automatic tax calculation (state/country-specific)
Surcharge management (regulatory fees, E911)

✅ Automated Invoicing

Scheduled invoice generation (monthly, quarterly, annual)
Professional PDF invoices with custom branding
Email delivery with payment links
Multi-currency support (USD, EUR, GBP, INR)

✅ Payment Processing

Stripe integration for credit card payments
ACH/bank transfer support
Auto-pay with saved payment methods
Dunning management (failed payment retry logic)

💡 Key Features

Customer Self-Service Portal

Dashboard: Overview of current balance, usage, active services
Invoice History: Download past invoices, view payment history
Payment Methods: Add/remove credit cards, set default payment method
Usage Reports: Real-time call logs, usage graphs, cost breakdown
Service Management: Add DIDs, upgrade/downgrade plans, request features
Support Tickets: Integrated helpdesk system

Admin Features

Financial Dashboard: MRR (Monthly Recurring Revenue), ARR, churn rate, LTV
Account Management: Create/edit accounts, apply credits, adjust balances
Rate Management: Define pricing plans, carrier cost tracking, margin analysis
Collections: Overdue invoice tracking, automated reminders, suspension workflow
Reports: Revenue by product, usage by account, profitability analysis

Integration with VoIP Infrastructure

Real-Time CDR Import: Asterisk CDRs imported every 5 minutes via MySQL replication
Balance Checking: API endpoint for Asterisk to check account balance before allowing calls
Auto-Suspension: Accounts exceeding credit limit automatically suspended in PBX
DID Provisioning: Automatic DID assignment and routing when purchased

🔧 Technical Challenges Solved

High-Volume CDR Processing

Challenge: Processing 100K+ CDRs/day in real-time without impacting application performance.

Solution: Implemented Laravel queue workers with Redis. CDR import runs in background jobs, rating engine processes in batches of 1,000. Separate database read-replica for CDR queries.

Complex Rating Logic

Challenge: Rating rules vary by customer (per-second vs per-minute, different rates by destination).

Solution: Built flexible rating engine with strategy pattern. Each account has assigned rate plan with custom rules. Supports: increments (6/6, 1/1), minimum duration, connection fees, destination-based pricing.

Invoice Generation Performance

Challenge: Generating PDF invoices for 2,000 accounts takes hours, blocking the system.

Solution: Move invoice generation to queued jobs. Process 100 invoices per job, run 10 workers in parallel. Completion time reduced from 6 hours to 30 minutes. Pre-calculate invoice totals and cache.

Payment Security & PCI Compliance

Challenge: Handling credit cards requires PCI DSS compliance—expensive and complex.

Solution: Use Stripe for all payment processing. Never store card details on our servers—only Stripe tokens. Reduces PCI scope to SAQ-A (simplest level). SSL everywhere, IP whitelisting for admin access.

📊 Performance Metrics

2,000+

Active Accounts

100K+

CDRs Processed Daily

$500K+

Monthly Billing Volume

95%

Payment Success Rate

🔐 Security Features

PCI DSS Compliant: Using Stripe for card processing—no card data stored locally
Two-Factor Authentication: Required for admin panel access
Role-Based Access Control: Granular permissions (billing, support, admin)
Audit Logging: All financial transactions logged with user/timestamp
Encrypted Communication: SSL/TLS for all web traffic and API calls
Rate Limiting: Protection against brute force and API abuse

💰 Financial Impact

Metric	Before System	After System
Invoice Generation Time	40 hours/month (manual)	30 minutes (automated)
Billing Errors	~10% dispute rate	<0.5% dispute rate
Collection Rate	85% (manual follow-up)	98% (automated reminders)
Support Tickets (Billing)	200/month	80/month (-60%)

🚀 Results

✅ Automated billing for 2,000+ accounts
✅ Processes $500K+ monthly billing volume
✅ Reduced billing staff time by 90%
✅ Improved payment collection rate to 98%
✅ Self-service portal reduced support tickets by 60%
✅ Zero billing disputes due to transparent usage tracking

🔮 Future Enhancements

🔹 AI-powered fraud detection (unusual usage patterns)
🔹 Predictive churn analysis (identify at-risk accounts)
🔹 Cryptocurrency payment support
🔹 Mobile app for iOS/Android
🔹 White-label solution for resellers

🎯 Technology Highlights

Built with Laravel 11 - modern PHP framework
Queue-based architecture - handles high-volume async processing
Stripe integration - PCI-compliant payment processing
Vue.js 3 - reactive customer portal
Redis caching - sub-second page loads
Master-slave DB replication - read/write separation for performance

VoIP Billing & Account Management System