The best open-source accounting software in 2026 (self-hosted bookkeeping and invoicing)

The best open-source accounting software in 2026 is Bigcapital for small-business bookkeeping, ERPNext when accounting must sit inside a full ERP, and LedgerSMB for classic double-entry books on PostgreSQL. For invoicing, Invoice Ninja and InvoiceShelf lead. Watch the licences: two popular names, Akaunting and Invoice Ninja, are source-available, not OSI open source.

Accounting is where "open source" claims most need checking. We read the LICENSE file of every project below, not just the GitHub badge, and dropped anything archived or untouched for over a year. Star and commit figures are GitHub snapshots from early October 2026; each app page shows live numbers.

Open-source accounting software compared

App	Best for	Stars	Commits (12 mo)	Licence	Stack
Bigcapital	Small-business double-entry books	3,921	1,005	AGPL-3.0	TypeScript
ERPNext	Accounting inside a full ERP	39,821	6,664	GPL-3.0	Python
LedgerSMB	Traditional books on PostgreSQL	570	710	GPL-2.0	Perl
Odoo	Invoicing within the Odoo suite	54,848	10,679	LGPL-3.0 (Community)	Python
Akaunting	Sole traders inside its free limits	10,159	518	BSL 1.1 (source-available)	PHP
Invoice Ninja	Invoicing and getting paid	10,223	2,002	Elastic 2.0 (source-available)	PHP
InvoiceShelf	OSI-licensed invoicing	1,846	733	AGPL-3.0	PHP
hledger	Plain-text accounting	4,746	1,992	GPL-3.0	Haskell

Browse the full list in the Accounting & Invoicing category.

Bigcapital: the best dedicated accounting app

Bigcapital is accounting and inventory software for small and medium businesses. It keeps double-entry books, produces financial statements and exposes an API so other systems can post transactions into it ("headless accounting").

• Pros: AGPL-3.0 with no paid edition gating the core; official Docker and Docker Compose guide; active development (over 1,000 commits in the last year).
• Cons: still versioned below 1.0 (v0.25 at the time of writing), so expect changes between releases; a smaller community than the big ERPs.

ERPNext: full accounting inside an open ERP

ERPNext's accounting module covers everything from recording transactions to financial reports, and it is wired to sales, purchasing, stock, manufacturing and projects. Every part is GPL-3.0 with no closed edition.

• Pros: the most complete open-source books here, including multiple companies; one system for invoices, stock and accounts; official Docker setup.
• Cons: you run a full ERP stack (Python, MariaDB, Redis) even if you only want the ledger; setting up a chart of accounts and workflows takes time.

If you are also considering a lighter ERP, read ERPNext vs Dolibarr.

LedgerSMB: traditional double-entry accounting

LedgerSMB is a web-based double-entry accounting system with quotations, ordering, invoicing, projects, timecards, inventory and shipping, storing its data in PostgreSQL. It has been around for many years and is aimed squarely at small and midsize businesses.

• Pros: proper accounting-first design; an official Docker Compose setup; GPL-2.0.
• Cons: a Perl codebase and a more traditional interface; a small community (570 stars), though development is steady.

Odoo: invoicing as part of a larger suite

Odoo's LGPL-3.0 Community edition includes invoicing alongside CRM, sales, inventory and POS. The full Accounting app and several other features are Enterprise-only, so check Odoo's edition comparison before relying on it for your books. See Odoo vs ERPNext.

Akaunting: polished, with real limits

Akaunting is a Laravel and Vue accounting app for small businesses and freelancers, with an App Store for extensions and support for MariaDB, MySQL, PostgreSQL or SQLite. It is one of the most-starred projects in this space, but its licence is the Business Source License 1.1. Free production use is limited to two users, one company and 1,000 invoices, and you may not rebrand it or offer it as an accounting service. Each version becomes GPLv3 four years after release.

• Pros: friendly interface; flexible database support; good fit for a sole trader inside the limits.
• Cons: not OSI open source; outgrow the limits and you need a paid on-premise plan.

Invoice Ninja: the most complete invoicing app

Invoice Ninja 5 handles quotes, invoices, recurring billing, payments, expenses and a client portal, with official desktop and mobile apps that connect to self-hosted servers. The self-hosted code includes all Pro and Enterprise features; a $40-per-year white-label licence removes the branding.

• Pros: the richest invoicing feature set; Docker image plus Cloudron, Softaculous and YunoHost packages.
• Cons: the Elastic License 2.0 is source-available, and forbids offering Invoice Ninja to others as a hosted service. It is invoicing, not full double-entry accounting.

Compare the two directly in Akaunting vs Invoice Ninja.

InvoiceShelf: OSI-licensed invoicing

InvoiceShelf, a fork of Crater, covers invoices and estimates with PDF export, payments, expenses, taxes, recurring invoices, a customer portal and multiple companies, under AGPL-3.0. A public demo resets automatically.

• Pros: genuinely open source; official Docker Compose setup with a SQLite option for small installs.
• Cons: the default 3.x branch is an alpha preview, so use the 2.x release for production data, as the README advises.

Plain-text accounting: hledger and Fava

If you are comfortable with text files and version control, hledger (GPL-3.0) keeps double-entry books in plain text and offers command-line, terminal and web interfaces, with strong CSV import. Fava is a web interface for the Beancount format. Both are excellent for freelancers and technical founders who want full control and an audit trail in Git, but they are not point-and-click tools for a bookkeeper.

Other tools worth a look

• InvoicePlane (MIT) and SolidInvoice (MIT): mature, focused invoicing for small businesses.
• Invoicerr (AGPL-3.0): freelancer invoicing with e-invoice XML formats such as Factur-X, UBL, XRechnung and Peppol BIS, useful where e-invoicing is mandatory.
• Invio (public domain, Unlicense): deliberately minimal; create an invoice, share a link, get paid.
• TaxHacker (MIT): uses an LLM of your choice, including a local one, to extract data from receipts and invoices. Its README says it is early in development, so treat it as a helper, not your system of record.
• ERPSAAS (MIT): a Laravel double-entry accounting platform, though only a handful of commits landed in the last year.

Open source vs source-available: why it matters for your books

Your accounting data has to stay readable for years, often for as long as tax authorities can audit you. That makes the licence more than a technicality. With an OSI licence such as GPL, AGPL or MIT, you, a contractor or a community fork can keep the software running even if the original company changes direction. With a source-available licence, the vendor sets the rules: Akaunting's BSL caps free use by users, companies and invoice count, and Invoice Ninja's Elastic License blocks anyone from running it as a service for others.

Neither is a reason to avoid those apps outright. Invoice Ninja's terms do not affect a business hosting it for its own invoicing, and a sole trader can stay inside Akaunting's limits. Just make the choice knowingly, and keep regular exports of your data in an open format.

Before you migrate your books

• Pick a clean cut-over date, usually the start of a month or financial year, and enter opening balances from your old system's trial balance rather than importing years of history.
• Export everything from the old tool first: customers, suppliers, items, open invoices and the chart of accounts, in CSV where possible.
• Check the features your jurisdiction needs: multi-currency, tax rates and reports, e-invoicing formats and audit trails differ a lot between these apps.
• Give your accountant access or agree on an export format before year-end, so closing the books does not become a data-conversion project.
• Automate backups of the database and uploaded files, and test a restore.

How to choose

• You need real books (balance sheet, P&L, reconciliation) for a small company: Bigcapital, or LedgerSMB if you prefer a long-established project.
• You also manage stock, purchasing or manufacturing: ERPNext.
• You mainly send invoices and chase payments: Invoice Ninja, or InvoiceShelf if you want an OSI licence.
• You are a freelancer who likes text files: hledger or Fava.
• You are replacing a specific product: see our open-source alternatives to QuickBooks, Xero, FreshBooks, Wave, Zoho Books and Sage.

Whichever you pick, back up the database off-site and test a restore before tax season. If you also run a shop, our best open-source POS systems roundup covers the till side, and for managing customers see the best open-source CRM.