The best open source alternative to Billsby is Lago. If that doesn't suit you, we've compiled a ranked list of other open source Billsby alternatives to help you find a suitable replacement. Other interesting open source alternatives to Billsby are: Autumn, OpenMeter, Flowglad, and Paymenter.
Billsby alternatives are mainly Subscription & Billing Management Tools but may also be Payment Infrastructure Tools or Cloud Cost & Optimization Tools. Browse these if you want a narrower list of alternatives or looking for a specific functionality of Billsby.
Open-source billing system that handles metering, usage-based pricing, and invoicing at scale. Perfect for AI, cloud, and API companies needing flexible monetization.

Lago delivers enterprise-grade billing infrastructure that scales with your business needs. The platform excels at processing high-volume usage data (up to 15,000 events/second) and converting it into accurate invoices through real-time metering.
Key capabilities include:
As an open-source solution, Lago provides full transparency and customization options. Companies can audit the code, maintain data control, and build custom features on top of the core platform. The system integrates seamlessly with popular tools like Stripe, NetSuite, AWS Marketplace, and accounting software.
Trusted by industry leaders including Mistral AI, Algolia, and Github, Lago has proven its ability to handle complex billing requirements at scale. The platform is particularly valuable for AI companies, cloud services, API providers, and fintech firms needing sophisticated usage-based monetization.
Looking for open source alternatives to other popular services? Check out other posts in the alternatives series and openalternative.co, a directory of open source software with filters for tags and alternatives for easy browsing and discovery.
Simplify Stripe integration for AI startups with 3 functions, 0 webhooks. Build pricing plans in 30 minutes with usage tracking, credits, and feature controls.

Transform complex Stripe billing into simple code with just 3 functions and zero webhooks. Autumn eliminates the complexity of payment integration, letting you build sophisticated pricing models in 30 minutes instead of weeks.
Key features include:
Built for developers by developers, Autumn provides drop-in React components and shadcn/ui variants. Handle upgrades, downgrades, and one-time payments with a single function call. The platform scales from free startups to enterprise customers processing over $50K monthly revenue.
No transaction fees beyond Stripe's standard rates (~0.7%). Start free until you reach $8K monthly revenue, then pay a flat fee with no surprises.
Open source billing platform that turns events into revenue with real-time metering, usage limits, and flexible pricing. Integrates with Stripe, CRMs, and payment providers.

OpenMeter transforms how AI and DevTool companies handle usage-based billing by providing real-time metering and flexible billing infrastructure. Built for developers and loved by product teams, it offers both open source and managed cloud solutions.
Key Features:
Developer-First Approach: OpenMeter provides SDKs for Node.js, Python, and Go with seamless integrations to Stripe, CRMs, and tax providers. The platform handles millions of events per second while maintaining SOC2 compliance with RBAC and SSO support.
Proven by Industry Leaders: Trusted by companies like Trigger.dev for per-millisecond compute billing, Requestly for API usage tracking, and backed by engineering leaders from Google, Netflix, and Stripe. The platform leverages battle-tested event-streaming techniques from high-scale production systems.
Quick Implementation: Get started in 5 minutes with comprehensive documentation, open source availability on GitHub under Apache 2.0 license, and a free forever cloud option with no credit card required.
Build payment systems with real-time billing state and full-stack SDK. Design pricing in natural language, deploy checkout and metering instantly with zero webhooks.

Open-source payment infrastructure that eliminates the complexity of traditional payment integrations. Build sophisticated billing systems without wrestling with webhooks or managing fragile data synchronization.
Real-time billing state means your application always has access to current customer entitlements and usage data directly from the source. No more webhook delays or sync failures that break your user experience.
The full-stack SDK provides React hooks and backend functions that let you implement checkout flows, customer portals, and usage tracking with minimal code. Design pricing models using natural language and deploy instantly.
Key advantages:
Built by developers for developers, with transparent pricing that scales with your business. Currently processes payments through Stripe with plans to support additional providers. Perfect for SaaS applications, API services, and any business requiring sophisticated billing logic without the traditional complexity.
Automate subscriptions and manage payments with a flexible, open-source billing system designed specifically for hosting providers.

A powerful billing platform built specifically for hosting businesses, Paymenter offers comprehensive payment management without vendor lock-in. The platform features automated subscription handling, multi-currency support, and seamless service deployment integration.
Key capabilities include:
The platform is highly customizable with themes and extensions, allowing you to create a tailored billing experience.
The system offers exceptional performance, responsive design across all devices, and cloud deployment options starting at $5/month. Perfect for hosting providers seeking a transparent, community-driven billing solution with extensive integration options.
Open-source pricing and billing platform that helps SaaS companies launch, test, and scale complex billing models with ease. Features metering, invoicing, and real-time data.

Flexible billing infrastructure designed for modern SaaS companies at any stage of growth. This open-source platform eliminates billing headaches by providing a comprehensive solution that separates pricing logic from payment processing.
Key capabilities include:
Developer-friendly features:
Modular architecture allows you to use the entire platform or pick specific modules that fit your needs. Built by an active open-source community with backing from the French State's France 2030 program, ensuring long-term sustainability and continuous innovation.
Looking for open source alternatives to other popular services? Check out other posts in the alternatives series and openalternative.co, a directory of open source software with filters for tags and alternatives for easy browsing and discovery.
BillaBear offers powerful tax management, automated workflows, and comprehensive subscription control for businesses using Stripe

BillaBear is a robust billing management solution designed to give businesses complete control over their billing processes. With its deep integration with Stripe, BillaBear offers a suite of powerful features to streamline and enhance your billing operations:
Powerful Tax Management:
Comprehensive Subscription Management:
Automated Workflows:
Flexible Integrations:
Multi-Brand Support:
Insightful Business Analytics:
Developer-Friendly Features:
BillaBear is built to scale, offering unlimited brands, advanced team permissions, and the option for self-hosting. Whether you're a growing startup or an established enterprise, BillaBear provides the tools you need to take full control of your billing processes and optimize your revenue management.
Replace expensive billing solutions with open-source software. Automate subscriptions, accept multiple payments including crypto, and gain real-time revenue insights.

Replace expensive proprietary billing systems with UniBee's open-source platform designed specifically for SaaS businesses. This comprehensive solution combines subscription management, payment processing, and revenue analytics in one powerful system.
Key advantages include:
The platform supports various billing models from simple recurring subscriptions to complex usage-based pricing. Whether you need cloud-based scalability or prefer self-hosted control, UniBee adapts to your infrastructure requirements.
Built for international operations, UniBee helps manage global customer bases with localized invoicing and regional payment methods. The transparent, community-driven development ensures continuous improvements and enhanced security.
Deployment flexibility means you can choose between cloud hosting for convenience or self-hosting for maximum data control. This makes UniBee suitable for startups through enterprise-level operations.