Invoice Ninja

Invoice Ninja is free, open-source invoicing and billing software built for freelancers, consultants and small businesses that need to look professional and get paid faster. Trusted by more than 200,000 businesses and running since 2014, it bundles invoicing, online payments, quotes, time tracking and expense management into one platform you can use in the cloud or self-host on your own server.

What is Invoice Ninja?

Invoice Ninja lets you create polished, branded invoices in minutes and send them to clients who can pay directly from the invoice in a single click. Around that core it adds the surrounding workflow most small businesses juggle across several tools: quotes and proposals, recurring and auto-billing, a branded client portal, expense and vendor tracking, and project management with Kanban boards.

Who it's for

The platform is a natural fit for freelancers, contractors, designers, developers, consultants and accountants — anyone who bills clients and wants a dependable, low-cost way to manage the money side of the business. The generous free plan makes it especially attractive for solo operators and new businesses watching every expense.

Key features

• Professional invoicing with customizable templates
• One-click online payments from the invoice
• Recurring and automatic billing
• Quotes, proposals and e-signatures
• Time tracking and Kanban-style project management
• Expense and vendor management
• A branded client portal
• Bank and credit-card transaction import
• Multi-factor authentication and PCI-DSS compliance

Payments and integrations

Invoice Ninja accepts payments through a wide range of gateways including Stripe, PayPal, Square and GoCardless, so clients can pay however they prefer. It connects with more than 50 services — QuickBooks, Gmail, Slack, Mailchimp and hundreds more — via Zapier, Make and Pabbly, and its API and self-hosting options make it a favorite among technically minded users who want full control of their data.

Open source and self-hosting

Unlike most billing tools, Invoice Ninja is open source with a public GitHub repository, and it can be self-hosted for teams that want to own their infrastructure and data outright. That transparency is a large part of why developers and privacy-conscious businesses gravitate to it.

Pricing

The Free plan is genuinely free forever and covers the essentials for a small client list, with no credit card required. Paid tiers add more templates, clients and advanced features: Ninja Pro at around $14/month, Enterprise at around $18/month, and a Premium Business tier for larger operations. A 30-day money-back guarantee backs the paid plans.

Getting paid faster

The whole product is oriented around shortening the gap between sending an invoice and receiving the money. Auto-billing charges recurring clients on schedule, payment reminders chase overdue invoices for you, and the one-click pay experience removes the friction that makes clients delay. Because customers can pay by card, PayPal or direct debit straight from the invoice, there are fewer excuses and fewer late payments.

Security and reliability

Invoice Ninja takes the money side seriously, with multi-factor authentication to protect accounts and PCI-DSS compliance for card handling. Self-hosting adds another layer of assurance for businesses that would rather keep financial data entirely on their own infrastructure, and the open-source codebase means the security model is transparent and auditable rather than a black box.

Why choose Invoice Ninja

Invoice Ninja's pitch is simple: professional invoicing and full billing workflow without the subscription bloat. The combination of a real free tier, open-source transparency, self-hosting and one-click payments makes it one of the best-value ways for independent businesses to bill clients and get paid on time. For freelancers and small teams who resent paying a premium just to send an invoice, it is one of the strongest options on the market.