Best Open Source Accounts Payable Software for Small Business (2026): 6 Tools Compared

Accounts payable (AP) is the money you owe suppliers. Small businesses need to record bills, track due dates and pay on time. These open source tools handle supplier bills inside an accounting system.

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

• ERPNext: Purchase invoices linked to orders.
• Dolibarr ERP CRM: Supplier invoices for small teams.
• LedgerSMB: Vendor invoices in double-entry books.

What to look for in accounts payable software for a small business

• Bill capture and due dates. Record bills quickly and see what falls due this week.
• Payment tracking. Mark bills paid, record partial payments and match them to the bank.
• Aging reports. An accounts payable aging report shows what is overdue.
• Approval before payment. Optional approval steps prevent mistaken payments.
• 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 accounts payable software

Stars and update dates are a snapshot from 16 October 2026 and change daily. They show activity, not quality.

The 6 best open source accounts payable tools, reviewed

1. ERPNext

Best for: Purchase invoices linked to orders
License: GPL-3.0 · Stack: Python (Frappe), MariaDB · GitHub: 40,232 stars, repo updated Oct 2026

Records supplier bills against purchase orders and payments, and shows what you owe in accounting reports.

Read our full guide to ERPNext · Source on GitHub · Official website

2. Dolibarr ERP CRM

Best for: Supplier invoices for small teams
License: GPL-3.0 · Stack: PHP, MySQL/MariaDB/PostgreSQL · GitHub: 7,732 stars, repo updated Oct 2026

Handles supplier invoices and payments in a PHP suite that runs on ordinary hosting.

Read our full guide to Dolibarr ERP CRM · Source on GitHub · Official website

3. LedgerSMB

Best for: Vendor invoices in double-entry books
License: GPL-2.0 · Stack: Perl, PostgreSQL · GitHub: 570 stars, repo updated Oct 2026

Web-based accounting with vendor invoices and payables in a proper double-entry model.

Source on GitHub · Official website

4. Bigcapital

Best for: Bills and vendors in a modern app
License: AGPL-3.0 · Stack: TypeScript (Node.js, React) · GitHub: 3,939 stars, repo updated Oct 2026

An accounting app with vendor bills and reporting, easier to learn than a full ERP.

Source on GitHub · Official website

5. Odoo Community

Best for: Vendor bills in the Invoicing app
License: LGPL-3.0 (Community edition) · Stack: Python, PostgreSQL · GitHub: 55,072 stars, repo updated Oct 2026

Odoo Community can record vendor bills. Advanced accounting features are part of Enterprise.

Read our full guide to Odoo Community · Source on GitHub · Official website

6. GnuCash

Best for: Payables on the desktop
License: GPL-2.0 or GPL-3.0 · Stack: C (desktop app) · GitHub: 4,378 stars, repo updated Oct 2026

GnuCash includes business features for vendors and bills for a single bookkeeper.

Source on GitHub · Official website

Open source vs paid accounts payable 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 accounts payable software

• You also run purchasing and stock: ERPNext.
• You want a simple suite: Dolibarr.
• You want only accounting: Bigcapital or LedgerSMB.
• You are a single bookkeeper: GnuCash.

Mistakes to avoid

Pay on time to protect supplier relationships and avoid late fees, and keep original bills as your local law requires. Make sure purchase tax or input credits are set up correctly 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.

Related comparisons

• Best Open Source Accounts Receivable Software (2026)
• Best Open Source Purchase Order Software for Small Business
• Best Open Source Vendor Management Software (2026)
• Best Open Source Bank Reconciliation Software (2026)

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.