Lago

Professional services firms often struggle with billing clients on complex, non-standard agreements that spreadsheets and basic invoicing tools can't handle. Lago is built specifically for this complexity. Instead of manually tracking billable hours against a retainer or calculating tiered project fees, you can automate it all. The platform's core strength is its ability to create 'hybrid plans,' combining recurring subscriptions with any number of usage-based metrics. This means you can model and bill for a monthly retainer plus metered consulting hours, all in one invoice. As an open-source platform, Lago provides complete transparency and control over your billing logic and data—a critical factor for financial operations. You can self-host it to meet strict data residency or security requirements. Proof of its capability comes from its adoption by tech leaders like Mistral AI for their own complex billing needs. With SOC 2 Type II compliance, Lago provides the enterprise-grade security necessary for handling sensitive client financial data, giving your firm a scalable, auditable, and automated billing engine.