Finance & Accounting
7 Best Open-Source Invoicing & Finance Tools for Freelancers (2026)
7 tools compared
Top Picks
<p>Freelancers have a love-hate relationship with invoicing. You love getting paid. You hate the 45 minutes every month spent wrestling with templates, chasing overdue payments, and reconciling bank transactions against a spreadsheet that stopped making sense three clients ago. <strong>The typical solution is a SaaS subscription — FreshBooks at $17/month, QuickBooks at $30/month, or Wave (now owned by H&R Block) with its transaction fees.</strong> For a freelancer earning $50-80K/year, that's $200-360/year just to send invoices and track expenses.</p><p>Open-source tools flip this equation entirely. You get professional invoicing, expense tracking, and financial reporting — often with features that rival paid platforms — <strong>without recurring subscription fees.</strong> The trade-off is that most require self-hosting, which means setting up a server (a $5/month VPS or even a Raspberry Pi). But for freelancers who value data ownership, customization, and not paying a middleman to manage their own money, the savings compound quickly. A freelancer switching from QuickBooks to a self-hosted Invoice Ninja saves $360/year <em>minimum</em> — and that's before accounting for the premium features locked behind expensive tiers in commercial tools.</p><p>We evaluated these seven open-source tools on the criteria that matter most to freelancers: <strong>ease of invoicing</strong> (how fast can you create and send an invoice?), <strong>payment collection</strong> (can clients pay online?), <strong>expense tracking depth</strong> (beyond basic categorization), <strong>self-hosting complexity</strong> (Docker one-liner or weekend project?), and <strong>financial reporting</strong> (can you generate reports come tax season?). Each tool occupies a distinct niche — from full accounting suites to lightweight time-billing apps — so your best choice depends on whether you need QuickBooks-level accounting or just a fast way to get invoices out the door.</p><p>Browse all tools in our <a href="/categories/finance-accounting">Finance & Accounting</a> and <a href="/categories/invoicing-billing">Invoicing & Billing</a> directories. If you're also considering paid options, see our guide to the <a href="/best/best-accounting-software-freelancers-solo-consultants">best accounting software for freelancers</a>.</p><p>One common mistake: <strong>choosing the most feature-rich tool instead of the one that matches your workflow.</strong> A freelance writer who invoices 3 clients monthly doesn't need double-entry bookkeeping. A freelance developer billing 15 clients across 3 currencies does. Match the tool to your complexity level, not the other way around.</p>
Full Comparison
Free open-source invoicing, expenses, and time-tracking for freelancers and small businesses
💰 Free plan for up to 5 clients. Pro plan at \u002414/month (\u0024140/year). Enterprise plan at \u002420/month (\u0024200/year).
<p><a href="/tools/invoice-ninja">Invoice Ninja</a> is the closest thing to a free QuickBooks for freelancers — and in many ways, it's better. <strong>The platform handles professional invoicing, online payments via 100+ gateways (Stripe, PayPal, Square, ACH), expense tracking, time tracking, and project management</strong> in a single self-hosted or cloud-hosted package. For freelancers who need to send polished invoices, accept payments instantly, and track billable hours, Invoice Ninja covers more ground than any other open-source tool on this list.</p><p>What makes Invoice Ninja particularly valuable for freelancers is the <strong>time-to-payment pipeline.</strong> Log hours with the built-in timer, convert tracked time into an itemized invoice, send it to your client through the branded portal, and get paid via their preferred payment method — all without leaving the platform. The client portal is a professional touch that many paid tools charge extra for: clients can view invoices, approve quotes, make payments, and download documents on their own. Recurring invoices with auto-billing eliminate the monthly invoicing chore entirely for retainer clients.</p><p>The free tier is generous — unlimited invoices for up to 5 clients — which covers most solo freelancers starting out. The Pro plan at $14/month unlocks 20 clients and removes Invoice Ninja branding. But the real power move is <strong>self-hosting the open-source version</strong>, which removes all client limits and gives you full control over your data. The Docker installation takes about 30 minutes for anyone comfortable with a terminal. Multi-currency support for 100+ currencies with automatic exchange rates makes it ideal for freelancers with international clients.</p>
Professional InvoicingOnline PaymentsExpense TrackingTime Tracking & ProjectsQuotes & ProposalsClient PortalMulti-Currency SupportPurchase Orders & VendorsBank Transaction ImportSelf-Hosted Option
Pros
- Supports 100+ payment gateways — clients can pay via Stripe, PayPal, Square, or ACH directly from the invoice
- Built-in time tracking with project management converts billable hours into invoices with one click
- Branded client portal for professional invoice delivery, quote approvals, and payment history
- Self-hosted version is completely free with no client or invoice limits
- Multi-currency invoicing in 100+ currencies with automatic exchange rate updates for international freelancers
Cons
- Free cloud tier limits you to 5 clients — most growing freelancers will need the $14/month Pro plan within a year
- Only Enterprise plan ($20/month) supports multiple users — unusable for small teams on lower tiers
- Interface can feel overwhelming initially due to the breadth of features beyond basic invoicing
Our Verdict: Best all-around open-source invoicing tool — the only free option with 100+ payment gateways, time tracking, and a client portal, making it the closest open-source equivalent to FreshBooks or QuickBooks.
Free open-source online accounting software for small businesses and freelancers
💰 Free (self-hosted). Cloud plans from $15/month. Premium self-hosted from $239/year.
<p><a href="/tools/akaunting">Akaunting</a> is what you choose when you need <em>accounting</em>, not just invoicing. <strong>Where Invoice Ninja excels at getting invoices out the door, Akaunting provides the full financial picture</strong> — profit & loss statements, balance sheets, cash flow reports, and tax management that your accountant will actually recognize. For freelancers whose finances have grown beyond "send invoice, receive money," Akaunting bridges the gap between simple invoicing and enterprise accounting software.</p><p>The multi-company management feature is a standout for freelancers running multiple businesses or side projects. <strong>Manage a consulting practice, an e-commerce store, and a content creation business from a single Akaunting installation</strong> with completely separate books for each. Bank account connections auto-import transactions for reconciliation, and the app store extends functionality with inventory management, payroll, and point-of-sale modules. It's modular — start with core invoicing and expenses, add capabilities as your business grows.</p><p>Built with Laravel and Vue.js, Akaunting has a modern web interface that feels closer to commercial accounting software than most open-source alternatives. The <strong>self-hosted version is completely free</strong> with no artificial limitations — unlimited users, clients, invoices, and companies. The premium tiers ($239-399/year) add advanced apps and priority support, but the free version covers everything most freelancers need. The learning curve is steeper than Invoice Ninja or SolidInvoice, but the financial reporting alone justifies the investment for freelancers earning $75K+ who need proper books.</p>
Invoicing & BillingExpense TrackingFinancial ReportingMulti-Currency SupportMulti-Company ManagementClient PortalBank ConnectionsApp StoreRESTful APITax Management
Pros
- Full accounting suite with profit & loss, balance sheet, and cash flow reporting — not just invoicing
- Multi-company management lets freelancers with multiple income streams keep separate books in one installation
- Extensible app store adds inventory, payroll, and POS capabilities as your business grows
- Free self-hosted version has no user, client, or feature limitations
- Modern Laravel/Vue.js interface that feels professional compared to legacy open-source accounting tools
Cons
- Steeper learning curve than simpler invoicing tools — expect a weekend to set up and configure properly
- Premium apps for advanced features cost $239-399/year, which erodes the 'free' advantage for power users
- Can feel over-engineered for freelancers who just need to send invoices and track a few expenses
Our Verdict: Best open-source accounting suite for freelancers — choose this when you need proper financial statements and multi-business management, not just invoice generation.
Open-source time tracking for teams and freelancers
💰 Free (self-hosted), Cloud from €2.99/user/mo
<p><a href="/tools/kimai">Kimai</a> approaches freelancer finance from the other direction: <strong>start with time tracking, end with an invoice.</strong> If your freelance work is billed by the hour — consulting, development, design, writing — Kimai's workflow is the most natural on this list. Start a timer when you begin working, stop it when you're done, categorize the entry by client and project, and at the end of the week or month, generate a professional invoice directly from your tracked hours. No manual data entry, no copying time logs into a separate invoicing tool.</p><p>Originally created in 2006 and actively maintained since, Kimai has the maturity and stability that newer tools sometimes lack. <strong>Unlimited users with role-based permissions</strong> make it equally suitable for solo freelancers and small agencies where multiple people track time against shared projects. The reporting engine exports to Excel and CSV for detailed analysis, and the plugin ecosystem adds features like approval workflows, vacation tracking, and customer budgets. Cloud hosting starts at just €2.99/user/month for teams that don't want to self-host.</p><p>The key limitation for freelancers: Kimai is <strong>primarily a time tracker that generates invoices, not an invoicing platform that tracks time.</strong> The invoicing templates are functional but basic compared to Invoice Ninja's polished output. There's no built-in expense tracking, no payment gateway integration, and no client portal for online payments. For freelancers who bill exclusively by the hour and handle payments through bank transfer or separate payment tools, Kimai is excellent. For those who need full-featured invoicing with online payments, pair Kimai with another tool or choose Invoice Ninja instead.</p>
Time TrackingExpense TrackingInvoicingReporting & ExportsMulti-User & RolesAPI & IntegrationsSelf-HostingMulti-Language SupportTwo-Factor Authentication
Pros
- Seamless time-to-invoice workflow — tracked hours convert directly into client invoices with zero manual data entry
- Unlimited users with role-based permissions scale from solo freelancer to agency without per-seat cost increases
- Mature codebase (since 2006) with proven stability and an active plugin ecosystem
- Cloud hosting at €2.99/user/month is exceptionally affordable for teams that don't want to self-host
- Cross-platform browser-based interface works on any device including tablets for on-site time tracking
Cons
- No built-in expense tracking — time and invoicing only, limiting it as a standalone freelancer finance tool
- Invoice templates are functional but basic compared to Invoice Ninja's professional output
- No online payment gateway integration — clients can't pay directly from the invoice
Our Verdict: Best for hourly-billing freelancers — the most efficient time-to-invoice pipeline of any open-source tool, ideal for consultants, developers, and designers who bill by the hour.
Free open-source invoicing app for freelancers and small businesses
💰 Free and open-source (self-hosted only)
<p><a href="/tools/crater">Crater</a> is the rare open-source invoicing tool that <strong>takes mobile seriously.</strong> Built with React Native for iOS and Android alongside its Laravel/Vue.js web app, Crater lets you create and send invoices from your phone during client meetings, at job sites, or on the commute home. For freelancers in fields like photography, event planning, or contracting — where you're often away from a desk — mobile invoicing isn't a nice-to-have, it's essential.</p><p>The feature set is deliberately focused: <strong>invoices, estimates, expenses, payments, and reports.</strong> No time tracking, no project management, no accounting modules — just the core billing workflow done well. Create an estimate for a potential client, convert it to an invoice upon approval, record the payment when it arrives, and generate reports by client or time period for tax preparation. Multi-currency support handles international clients, and the client portal provides a professional interface for invoice delivery.</p><p>Crater is <strong>100% free with no premium tiers or hidden fees.</strong> It's self-hosted only — there's no managed cloud option — which means you need a server with PHP and MySQL. The community is smaller than Invoice Ninja's, and development has slowed somewhat in recent years. There's no built-in payment gateway integration, so clients can't click a button to pay online. But for freelancers who want a clean, mobile-friendly invoicing tool without any subscription overhead, Crater fills a specific niche that no other open-source tool matches.</p>
Professional InvoicingEstimates & QuotesExpense TrackingRecurring InvoicesMulti-Currency SupportClient PortalTax ManagementFinancial ReportsMobile AppsRESTful API
Pros
- Native iOS and Android apps — the only open-source invoicing tool with proper mobile support via React Native
- 100% free with no paid tiers, hidden fees, or premium features locked behind a paywall
- Clean, focused interface that handles invoicing and expenses without accounting complexity
- Estimate-to-invoice conversion workflow streamlines the freelancer client approval process
- Multi-currency support for international freelance billing
Cons
- Self-hosted only with no managed cloud option — requires a PHP/MySQL server to run
- No online payment gateway integration — clients must pay via bank transfer or external methods
- Smaller community and slower development pace compared to Invoice Ninja or Akaunting
- No time tracking features — hourly billers need a separate tool
Our Verdict: Best for mobile invoicing — the native iOS/Android apps make Crater the top choice for freelancers who create invoices away from their desk.
Free open-source desktop accounting software for small businesses and freelancers
💰 Free and open-source (desktop application)
<p><a href="/tools/frappe-books">Frappe Books</a> takes a fundamentally different approach from every other tool on this list: <strong>it's a desktop application that runs entirely offline.</strong> No server to set up, no cloud account to create, no internet connection required. Download the app, open it, and start creating invoices. Your financial data lives in a local SQLite file on your computer — it never touches the internet unless you explicitly choose to share it. For privacy-conscious freelancers who don't trust SaaS providers with their financial data, Frappe Books is the purest form of data sovereignty.</p><p>Despite being lightweight, Frappe Books includes <strong>proper double-entry bookkeeping</strong> — something most simple invoicing tools skip. Chart of accounts, journal entries, ledger views, profit & loss statements, and balance sheets are all built in. The invoicing interface generates clean PDF documents with customizable HTML templates, and the integrated point-of-sale module handles retail transactions for freelancers with a physical product component. A fuzzy search (Ctrl+K) lets you jump to any function or create invoices from anywhere in the app — a nice touch borrowed from developer tools.</p><p>The limitations are inherent to the desktop-only architecture: <strong>no multi-user access, no web interface, no mobile app, and no integrations with payment gateways or bank accounts.</strong> You can't send invoices directly from the app or accept online payments. For freelancers with simple needs — send a few invoices monthly, track expenses for tax season, generate basic financial reports — Frappe Books is beautifully simple. For anything requiring collaboration, online payments, or remote access, you'll need a web-based tool instead. Created by the team behind ERPNext (one of the most popular open-source ERP systems), the code quality and design polish are a cut above most open-source accounting software.</p>
Invoicing & BillingDouble-Entry AccountingPayment TrackingExpense ManagementFinancial ReportsPoint of SaleOffline-First DesignCustom Invoice TemplatesMulti-Currency SupportFuzzy Search
Pros
- Zero setup — download the desktop app and start invoicing immediately with no server or cloud account needed
- 100% offline operation means financial data never leaves your computer — maximum privacy
- Proper double-entry bookkeeping with chart of accounts, journal entries, and financial statements
- Beautiful, modern desktop interface that rivals paid software — built by the ERPNext team
- Completely free with no paid tiers, subscriptions, or feature limitations
Cons
- Desktop-only with no web interface, mobile app, or remote access capability
- No online payment gateway integration — invoices must be paid via external methods
- No multi-user or collaboration features — strictly a single-user tool
- Limited integrations with other tools compared to web-based alternatives like Invoice Ninja
Our Verdict: Best for privacy-first freelancers who want offline desktop bookkeeping — download, open, invoice, with zero cloud dependency and proper double-entry accounting.
Open-source invoicing software for freelancers and small businesses
💰 Free self-hosted. Cloud at $88/month or $80/year (annual). 30-day free trial, no credit card required.
<p><a href="/tools/solidinvoice">SolidInvoice</a> is the <strong>"just let me send an invoice" tool</strong> of the open-source world. While Invoice Ninja packs in time tracking, projects, and 100+ payment gateways, and Akaunting builds toward a full accounting suite, SolidInvoice focuses narrowly on doing invoicing well — creating invoices, sending them to clients, accepting payments via Stripe and PayPal, and following up on overdue balances. For freelancers who find Invoice Ninja overwhelming and don't need accounting, SolidInvoice hits the sweet spot of simplicity.</p><p>The core workflow is streamlined: <strong>create a client, generate an invoice or quote, send it, and collect payment.</strong> Recurring invoices handle retainer billing automatically, and payment reminders chase overdue invoices without manual follow-up. Multi-currency support covers international clients, and the client management system tracks contacts, notes, and activity history per client. Role-based permissions enable team collaboration when you bring on a virtual assistant or bookkeeper. The interface is clean and focused — you won't spend 20 minutes looking for the button to create an invoice.</p><p>SolidInvoice offers both a <strong>free self-hosted version and an affordable cloud option</strong> — the cloud runs $80/year (annual billing), which is competitive with commercial alternatives. The self-hosted version includes the full feature set. The main trade-off is feature depth: no time tracking, no expense management, no financial reporting beyond basic revenue tracking. SolidInvoice won't replace QuickBooks for freelancers with complex financial needs, but it will replace the "create invoice in Google Docs and email it as a PDF" workflow that too many freelancers still rely on.</p>
Unlimited Invoices & QuotesRecurring BillingOnline PaymentsAutomatic Payment RemindersClient ManagementMulti-Currency SupportTeam CollaborationFinancial ReportingREST APISelf-Hosted Option
Pros
- Clean, focused interface that does invoicing without the complexity of full accounting or project management
- Stripe and PayPal payment integration — clients can pay online directly from the invoice
- Affordable cloud hosting at $80/year for freelancers who don't want to self-host
- Automatic payment reminders reduce the manual work of chasing overdue invoices
- Multi-currency support and recurring billing cover the essentials for retainer-based freelancers
Cons
- No time tracking or expense management — strictly invoicing and payment collection
- Smaller ecosystem and community than Invoice Ninja or Akaunting
- Cloud pricing ($80/year) is higher per-feature than Invoice Ninja's Pro plan ($168/year) which includes more capabilities
- Limited financial reporting — no profit & loss or balance sheet generation
Our Verdict: Best for simplicity — the easiest open-source invoicing tool to set up and use, ideal for freelancers who want clean invoices with online payments and nothing more.
A free and open source personal finance manager
💰 Free and open-source (AGPL-3.0)
<p><a href="/tools/firefly-iii">Firefly III</a> isn't an invoicing tool — it's a <strong>personal finance command center for freelancers who treat their business finances like a serious operation.</strong> While every other tool on this list focuses on getting invoices out and payments in, Firefly III focuses on what happens to that money afterward: budgeting, expense categorization, savings goals, and financial reporting across every account you own. For freelancers juggling variable income, multiple bank accounts, and irregular expenses, Firefly III provides the financial visibility that invoicing tools alone can't deliver.</p><p>The <strong>double-entry bookkeeping system</strong> tracks every transaction across multiple accounts and currencies — business checking, personal savings, credit cards, PayPal, crypto. Automated rules categorize imported transactions ("any payment from Client X goes to the Consulting Income category"), and the budgeting system with "piggy banks" helps freelancers set aside money for taxes, equipment, and irregular expenses. The reporting engine generates expense breakdowns by week, month, or year — exactly what you need when estimating quarterly tax payments or analyzing which clients are actually profitable after expenses.</p><p>Firefly III is <strong>self-hosted only and completely free</strong> under the AGPL-3.0 license. The setup requires Docker or manual server configuration, and the learning curve is steeper than consumer budgeting apps like YNAB. There's no invoicing, no client management, no payment collection — it's purely for tracking and analyzing your finances. The ideal setup for a freelancer is <strong>Firefly III paired with Invoice Ninja</strong>: Invoice Ninja handles the client-facing billing pipeline, and Firefly III provides the personal finance intelligence layer that helps you understand where your money goes and whether your freelance business is actually profitable after all expenses.</p>
Double-Entry BookkeepingMulti-Currency SupportBudgeting & Piggy BanksAutomated Rules EngineData ImportAdvanced ReportingREST JSON APIRecurring Transactions
Pros
- Comprehensive personal finance tracking with double-entry bookkeeping across multiple accounts and currencies
- Automated rule engine categorizes bank transactions — saves hours of manual expense categorization each month
- Budgeting with piggy banks helps freelancers set aside money for taxes, equipment, and irregular expenses
- Completely free and self-hosted with no premium tiers — your financial data stays on your server
- Powerful REST API enables custom integrations and automated data imports from banks
Cons
- Not an invoicing tool — no invoice creation, client management, or payment collection features
- Steep learning curve with complex setup (Docker or manual server configuration required)
- No native mobile app — web-only interface that's functional but not optimized for phones
- Strict CSV import format requirements can be frustrating when importing bank data
Our Verdict: Best for financial tracking and budgeting — not an invoicing tool, but the ideal companion to pair with Invoice Ninja or Crater for freelancers who want complete visibility into their business finances.
Our Conclusion
<h3>Quick Decision Guide</h3><ul><li><strong>Need a full QuickBooks replacement</strong> → <a href="/tools/invoice-ninja">Invoice Ninja</a>. Invoicing, expenses, time tracking, 100+ payment gateways, and a client portal. The free tier covers most solo freelancers.</li><li><strong>Want proper accounting with financial reports</strong> → <a href="/tools/akaunting">Akaunting</a>. Profit & loss, balance sheets, and multi-company support from a free self-hosted install.</li><li><strong>Bill clients by the hour</strong> → <a href="/tools/kimai">Kimai</a>. The time-to-invoice pipeline is unmatched — start a timer, stop it, generate an invoice.</li><li><strong>Need to invoice from your phone</strong> → <a href="/tools/crater">Crater</a>. Native iOS/Android apps are rare in open-source invoicing.</li><li><strong>Want zero cloud dependency</strong> → <a href="/tools/frappe-books">Frappe Books</a>. Everything runs on your desktop with a local SQLite file.</li><li><strong>Just want simple invoicing, fast</strong> → <a href="/tools/solidinvoice">SolidInvoice</a>. Clean interface, Stripe/PayPal payments, no accounting complexity.</li><li><strong>Need expense tracking and budgeting (not invoicing)</strong> → <a href="/tools/firefly-iii">Firefly III</a>. The gold standard for self-hosted personal finance management.</li></ul><h3>Our Top Pick</h3><p>For most freelancers, <strong>Invoice Ninja is the best starting point.</strong> The free tier supports unlimited invoices for 5 clients, and the Pro plan at $14/month is still dramatically cheaper than FreshBooks or QuickBooks while offering comparable features. The self-hosted version removes all limits for free. It strikes the right balance between power and simplicity — sophisticated enough for multi-currency international work, but not so complex that you need an accounting degree to send an invoice.</p><p>For freelancers who want <em>accounting</em> (not just invoicing), <strong>Akaunting paired with a self-hosted install gives you a genuine QuickBooks alternative at zero cost.</strong> The learning curve is steeper, but your accountant will thank you at tax time when you hand them proper financial statements instead of a pile of invoices.</p><p>One trend worth watching: <strong>open-source invoicing tools are rapidly closing the gap with commercial alternatives.</strong> Invoice Ninja v5 and Akaunting both now offer features — like bank transaction imports and automated recurring billing — that were exclusive to paid platforms two years ago. If you tried open-source invoicing before and found it lacking, it's worth a second look. For more freelancer-focused guides, see our <a href="/best/best-ai-tools-freelancers-automate-workflow">best AI tools for freelancer automation</a> and browse our full <a href="/categories/invoicing-billing">invoicing & billing directory</a>.</p>
Frequently Asked Questions
Are open-source invoicing tools really free?
The self-hosted versions are genuinely free — you download the code and run it on your own server. The only cost is hosting ($5-10/month for a VPS). Some tools like Invoice Ninja and Akaunting also offer managed cloud versions with monthly fees, but the self-hosted option always remains free. Tools like Crater and Frappe Books are 100% free with no paid tiers at all.
Do I need technical skills to self-host invoicing software?
It depends on the tool. Invoice Ninja and Akaunting offer Docker one-click installs that most tech-comfortable freelancers can set up in under an hour. Frappe Books requires zero setup — just download the desktop app. Crater and Kimai need a PHP server with MySQL, which requires basic server administration knowledge. If self-hosting feels daunting, Invoice Ninja and Akaunting both offer affordable managed cloud plans.
Can open-source invoicing tools accept online payments?
Invoice Ninja supports 100+ payment gateways including Stripe, PayPal, and Square. SolidInvoice integrates with Stripe and PayPal. Akaunting supports payments through its app store extensions. Crater and Frappe Books focus on invoice generation and manual payment tracking — they don't have built-in payment gateway integration. For online payment collection, Invoice Ninja is the strongest option.
Which open-source tool is best for tax reporting?
Akaunting provides the most comprehensive financial reporting with profit & loss statements, balance sheets, and configurable tax rates. Invoice Ninja tracks expenses and generates reports but isn't a full accounting system. Firefly III excels at personal finance tracking with detailed expense categorization. For proper tax-ready financial statements, Akaunting or Frappe Books (with double-entry bookkeeping) are your best options.
Can I migrate from QuickBooks or FreshBooks to an open-source tool?
Most open-source invoicing tools support CSV imports for client lists, invoices, and expenses. Invoice Ninja has the most robust import system, supporting data from FreshBooks, Zoho, and Wave directly. For QuickBooks, you'll typically export to CSV and import into your new tool. The migration takes 1-3 hours for most freelancers. Start by running both tools in parallel for a month to ensure nothing falls through the cracks.