Quick answer
The best open source invoicing software for most small businesses is InvoicePlane, with InvoiceShelf and Invio as strong alternatives. Verified 16 October 2026.
Invoicing is the first thing most small businesses automate. The good news is that there are several free, self-hostable invoicing apps. The bad news is that some of the best-known names are not truly open source, so check licenses before you commit.
We write for small businesses, freelancers and growing teams, not large enterprises. Every tool below was checked on GitHub for license, archive status and recent activity, and prices are never quoted because they change. Our picks are based on each project's documentation and repository data, not on hands-on benchmarks, so always try a tool with sample data first. This is general information, not tax, legal or accounting advice.
Top picks at a glance
- InvoicePlane: Simple self-hosted invoicing and quotes.
- InvoiceShelf: Modern invoicing with estimates and expenses.
- Invio: Minimal, no-frills invoicing.
What to look for in invoicing software for a small business
- Quotes and recurring invoices. Check that you can turn a quote into an invoice and repeat invoices on a schedule.
- Tax and numbering. Make sure tax rates, invoice numbering and required fields match your country's rules.
- PDF and email. Branded PDF invoices and email delivery should work without extra plugins.
- Online payment links. If you want customers to pay online, check supported gateways.
- Project health and license. Choose a project that is not archived, has recent releases and a real open source license. Check the LICENSE file, not just the website.
Comparison table: best open source invoicing software
| Tool | Best for | License | Stack | GitHub stars | Repo updated |
|---|---|---|---|---|---|
| InvoicePlane | Simple self-hosted invoicing and quotes | MIT | PHP | 3,208 | Oct 2026 |
| InvoiceShelf | Modern invoicing with estimates and expenses | AGPL-3.0 | PHP (Laravel), Vue | 1,857 | Oct 2026 |
| Invio | Minimal, no-frills invoicing | Unlicense | TypeScript | 1,193 | Oct 2026 |
| Bigcapital | Invoices connected to real accounting | AGPL-3.0 | TypeScript (Node.js, React) | 3,939 | Oct 2026 |
| Dolibarr ERP CRM | Invoices, proposals and stock together | GPL-3.0 | PHP, MySQL/MariaDB/PostgreSQL | 7,732 | Oct 2026 |
| ERPNext | Invoicing inside a full ERP | GPL-3.0 | Python (Frappe), MariaDB | 40,232 | Oct 2026 |
| IDURAR ERP CRM | Invoices, quotes and payments on Node.js | AGPL-3.0 | Node.js, React, MongoDB | 8,878 | Aug 2026 |
Stars and update dates are a snapshot from 16 October 2026 and change daily. They show activity, not quality.
The 7 best open source invoicing tools, reviewed
1. InvoicePlane
Best for: Simple self-hosted invoicing and quotes
License: MIT · Stack: PHP · GitHub: 3,208 stars, repo updated Oct 2026
A long-running, MIT-licensed PHP application for managing invoices, quotes and clients. Easy to host on standard PHP hosting.
Source on GitHub · Official website
2. InvoiceShelf
Best for: Modern invoicing with estimates and expenses
License: AGPL-3.0 · Stack: PHP (Laravel), Vue · GitHub: 1,857 stars, repo updated Oct 2026
Open source invoicing with estimates and expense tracking. AGPL-licensed and actively maintained.
Source on GitHub · Official website
3. Invio
Best for: Minimal, no-frills invoicing
License: Unlicense · Stack: TypeScript · GitHub: 1,193 stars, repo updated Oct 2026
A lightweight self-hosted invoicing app released under the Unlicense. Good when you want something small and simple.
Source on GitHub · Official website
4. Bigcapital
Best for: Invoices connected to real accounting
License: AGPL-3.0 · Stack: TypeScript (Node.js, React) · GitHub: 3,939 stars, repo updated Oct 2026
Invoicing inside a full accounting app, so invoices feed your financial reports automatically.
Source on GitHub · Official website
5. Dolibarr ERP CRM
Best for: Invoices, proposals and stock together
License: GPL-3.0 · Stack: PHP, MySQL/MariaDB/PostgreSQL · GitHub: 7,732 stars, repo updated Oct 2026
Covers customer invoices, commercial proposals and stock in one application that runs on ordinary hosting.
Read our full guide to Dolibarr ERP CRM · Source on GitHub · Official website
6. ERPNext
Best for: Invoicing inside a full ERP
License: GPL-3.0 · Stack: Python (Frappe), MariaDB · GitHub: 40,232 stars, repo updated Oct 2026
Sales invoices linked to orders, delivery and accounting. Best when invoicing is only one part of your operations.
Read our full guide to ERPNext · Source on GitHub · Official website
7. IDURAR ERP CRM
Best for: Invoices, quotes and payments on Node.js
License: AGPL-3.0 · Stack: Node.js, React, MongoDB · GitHub: 8,878 stars, repo updated Aug 2026
A JavaScript ERP/CRM with invoices and quotes, handy if your team already works in Node and React.
Read our full guide to IDURAR ERP CRM · Source on GitHub · Official website
Open source vs paid invoicing software
Paid cloud products usually win on polish, mobile apps, automatic bank connections and support. Open source wins on running cost as you grow, data ownership and the freedom to customize. The real cost of open source is hosting, backups, updates and your own time, so count those honestly. Several of these projects also sell hosting or support if you would rather not run a server yourself.
How to choose the best invoicing software
- You want the simplest self-hosted tool: InvoicePlane or InvoiceShelf.
- You want invoices to feed accounting: Bigcapital.
- You also manage stock and proposals: Dolibarr or ERPNext.
- You want something tiny: Invio.
Popular tools that are not open source (or not maintained)
These names show up in many "open source" lists, so check the license before you choose them:
- Invoice Ninja: Licensed under the Elastic License 2.0, which is source-available but not open source. Repository
- Akaunting: Licensed under the Business Source License (BSL), a source-available license, not an open source license. Repository
- Crater: No repository update since August 2024. InvoiceShelf is a maintained alternative. Repository
Checked from the projects' LICENSE files and GitHub status on 16 October 2026. Licenses can change.
Mistakes to avoid
Invoice Ninja is popular but uses the Elastic License 2.0, so it is source-available rather than open source. Akaunting uses the Business Source License. Crater has not been updated since August 2024, and InvoiceShelf is a maintained alternative. Invoice rules differ by country, so confirm required fields with your accountant.
Where to host it
All of these tools can be self-hosted. A small VPS or a web hosting plan from a provider such as Hostinger is enough to get started with most of them. Check each project's requirements first, and read our security and backup checklist before you add real data.
Need a server to host it?
Self-hosting a CRM needs a server. PHP and MySQL apps can often run on ordinary web hosting, while Docker, Node, Python or Java apps usually need a VPS. Check each project's requirements first. Hostinger offers both shared web hosting and VPS plans.
Affiliate disclosure: this is an affiliate link. If you buy through it we may earn a commission at no extra cost to you. CRMs are listed independently of any hosting partner. Learn more.
Related comparisons
- Best Open Source Quotation & Estimates Software (2026)
- Best Open Source Accounts Receivable Software (2026)
- Best Open Source Billing Software for Small Business
- Best Open Source Accounting Software for Small Business
All open source business software comparisons
- Accounting
- Bookkeeping
- Billing
- Invoicing
- Payroll
- Inventory Management
- Warehouse Management
- Expense Tracking
- Spend Management
- Accounts Payable
- Accounts Receivable
- Cash Flow Management
- Bank Reconciliation
- Purchase Order
- Vendor Management
- Point of Sale (POS)
- Time Tracking
- Quotation & Estimates
- Revenue Recognition
- Financial Reporting
- Asset Management
- Lead Management
- Sales Pipeline
- ERP
Also see our directory of 50 open source CRMs.