With nearly 10,000 GitHub stars and over a decade of development since 2013, Invoice Ninja is the most complete source-available invoicing platform for freelancers and small businesses — combining professional invoicing, online payments, expense tracking, and project management in a single self-hosted application. The Laravel API backend powers a React web portal and Flutter native applications for Windows, macOS, Linux, iOS, and Android, delivering a consistent experience across every device. Create professional invoices and quotes with real-time PDF preview, product libraries, custom templates, and automatic tax calculations. Clients receive branded emails and access their dedicated portal at your custom domain to view documents, approve quotes with e-signatures, and pay with one click via Stripe, PayPal, Square, GoCardless, Authorize.net, Braintree, or Mollie. Recurring invoices with auto-billing charge saved payment methods on schedule — weekly, monthly, or annually — with automatic reminders and late fee calculations. The built-in project management suite includes Kanban boards for task organization, billable time tracking with start/stop timers, and vendor expense management with receipt attachments. Bank account synchronization via Yodlee or GoCardless automatically imports transactions for reconciliation. E-invoicing with PEPPOL network integration supports electronic invoicing standards for European and government compliance. Reports cover invoices, expenses, profit and loss, tax summaries, and aged receivables. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Elastic License v2.

SolidInvoice ships a complete billing platform as a single FrankenPHP binary — no separate PHP installation, no web server configuration, just one executable that delivers quote-to-invoice conversion, automated recurring billing, Stripe and PayPal payment processing, multi-currency precision arithmetic, and eight render-ready PDF templates out of the box. Maintained since 2012 across 63 releases with 30 contributors, the Symfony 7 and PHP 8.4 backend provides quote creation with one-click conversion to invoices, recurring billing with configurable frequency schedules, and online payment processing through Payum supporting Stripe, PayPal, and additional gateways. Multi-currency support uses real Money objects for precision arithmetic, while multi-tax support handles invoice-level and line-item tax rates with automatic calculation. Client management stores contacts, multiple addresses with map integration, credit balances, and complete quote and invoice history per client. The redesigned Tabler-based UI features a dashboard with hero statistics, ChartJS revenue trend visualization, attention-required alerts for overdue and draft invoices, quick actions, and a recent activity timeline. A RESTful API enables integrations with external systems. Multi-channel notifications deliver alerts via email, SMS, and webhooks. Google OAuth and two-factor authentication secure access. Grid export and full company data export support backup and migration. Deploy using Docker, Homebrew, the standalone FrankenPHP binary, or from source. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Create an invoice, share a secure link, get paid — that's the entire workflow, no client portals or account registrations required. Invio distills billing into its absolute minimum viable surface while still producing legally compliant EU electronic invoices in Factur-X/ZUGFeRD 2.2 BASIC, UBL 2.1, and Italian FatturaPA formats, all embedded as XML attachments inside WeasyPrint-rendered PDFs. The Deno 2 backend uses Hono v4 for HTTP routing with SQLite persistence, while the SvelteKit 2 frontend styled with Tailwind CSS v4 and DaisyUI v5 delivers a responsive interface that stays out of your way. The team access system includes a permission matrix, TOTP-based two-factor authentication, and OIDC integration with configurable auto-provisioning — drop it into existing identity infrastructure without manual user management. Preset products let you build invoices from reusable catalog items. A change history log tracks every modification for audit purposes. Rate limiting protects the API behind reverse proxies. The entire stack ships as a single multi-stage Docker image containing Deno, Bun, Node, WeasyPrint, and all required font packages — zero external service dependencies beyond the container itself. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Unlicense licensed.

Invoicerr nails the exact billing sequence freelancers actually use: draft a quote, send it to the client, collect a legally-binding electronic signature via a secure browser link, convert the approved quote into an invoice, and generate a branded PDF — no DocuSign account, no external signing service, no enterprise complexity. The React frontend with NestJS backend uses Prisma ORM with your choice of SQLite for instant local setup or PostgreSQL for production workloads. Quotes and invoices are first-class objects with independent status tracking — unread, sent, viewed, signed for quotes; paid for invoices — not a single form with a label swap. The e-signature system generates secure-token signing links that clients open in their browser to review and sign documents without needing any account or external service. PDF generation renders quotes, invoices, and receipts with your company logo, name, VAT number, colors, and custom email templates so documents reflect your brand identity rather than the software's defaults. Authentication supports JWT tokens or OIDC providers stored in cookies. The REST API backend enables future integrations with mobile and desktop clients. A plugin system with community-made features and outgoing webhooks extends functionality without forking core code. International-friendly with customizable currencies. Deploy with Docker Compose using the prebuilt image from GitHub Container Registry. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.

Named after the Bosnian word for invoice (račun) with a raccoon twist, Rachoon provides a clean self-hosted invoicing platform that handles the complete billing cycle from quotation to payment reconciliation without touching a third-party SaaS subscription. The Nuxt.js frontend serves a dashboard that surfaces revenue totals, pending balances, overdue items, and client statistics at a glance, while the AdonisJS backend manages all business logic against a PostgreSQL 16 database with TypeScript throughout the full stack. Invoice templates use Nunjucks with full HTML and CSS control—including conditional logic, loops, and custom formatting—so the rendered PDFs actually match your design intent. This is possible because Rachoon delegates PDF generation to Gotenberg, which renders invoices through headless Chrome rather than a restricted drawing API, producing output that faithfully preserves complex layouts, web fonts, and CSS grid. Client records stay organized and searchable, each linked to their invoice and quotation history with payment status tracking across pending, paid, and overdue states. Multi-currency billing with flexible tax configuration supports international operations, and all data remains on your own infrastructure. The monorepo is managed by Turborepo with a CI pipeline covering linting, PostgreSQL integration tests, build verification, and multi-platform Docker image creation for both amd64 and arm64 architectures. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.

InvoicePlane manages the complete freelance and small-business billing cycle — draft quotes, convert them to invoices, automate recurring charges, collect payments through Stripe and PayPal, and generate EU-compliant eInvoice XML for automated processing by accounting systems. Deployed over 100,000 times across 193 countries, the PHP 8.2+ application on CodeIgniter 3 with MySQL or MariaDB handles everything from first estimate to final receipt. EU-compliant eInvoice generation creates machine-readable XML invoices meeting European Union standards since version 1.6.2. Recurring invoices automate periodic billing with configurable controls that pause generation when previous invoices remain unpaid. Online payment integration lets clients pay directly through Stripe, PayPal with Advanced Credit Cards, and Venmo support. The CRM-like client management module stores contact details, notes, custom fields, and complete transaction history per client. Product and task management modules let you build line-item invoices from reusable product catalogs and project tasks. Customizable PDF templates powered by mPDF support branded invoice layouts with QR codes, while email delivery via PHPMailer handles automated sending with configurable SMTP. A guest portal gives clients read-only access to view and pay their outstanding invoices and quotes. Financial reporting tracks revenue, outstanding balances, and payment history. The multi-language interface supports community translations, and multi-currency handles international invoicing. Deploy via Docker Compose with automatic database migrations. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Akaunting is an online accounting software for small businesses and freelancers. The double-entry accounting engine provides a full Chart of Accounts, journal entries, and balance sheet reporting, eliminating the manual errors inherent in single-entry systems. Unlimited invoice creation with customizable templates, automatic payment reminders, and client portal access lets businesses present professional documents and accept payments through PayPal, Stripe, and other gateway integrations. Expense tracking captures operational costs with category-based organization, receipt scanning, and vendor bill management with overdue payment alerts. Bank Feeds auto-syncs transactions from connected bank accounts and matches them against invoices and bills for streamlined reconciliation. The dashboard displays receivables, payables, cash flow summaries, profit and loss charts, expenses by category, and account balances at a glance with configurable date ranges. Quotes and estimates convert directly into invoices upon client approval, while recurring invoices and bills automate periodic billing without manual intervention. The modular architecture built on Laravel with the Akaunting Module package enables an App Store where developers publish extensions for payroll, inventory, projects, and CRM functionality. Multi-company support manages separate books from a single installation with per-company user roles. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. BSL licensed.

Quote to cash in one web application - create quotes, convert them to invoices, record payments, track customers: iDURAR is an open-source ERP and CRM platform for small and medium-sized businesses. Built on the MERN stack (MongoDB, Express, React, Node.js) with Ant Design components and Redux state management, it presents a clean SaaS-style interface that needs little onboarding. Core modules cover invoice management with PDF generation and email delivery, payment recording against invoices, quote and proforma handling, customer records, and accounting views over the resulting data. Multi-currency support and localization make it usable for internationally operating teams. Because the whole stack is JavaScript with an API-first backend, extending it - custom fields, new modules, integrations - is approachable for any Node/React developer rather than requiring a specialist ERP skill set. Deployment is straightforward via Docker with a MongoDB instance. Licensed under AGPL-3.0 with free commercial use; a hosted enterprise version exists but the self-hosted edition is fully functional.

Bigcapital gives small and medium businesses a complete double-entry accounting, invoicing, and inventory management platform they can self-host for free, replacing the per-seat subscriptions of QuickBooks, Xero, and Wave. Every transaction records debits and credits across your chart of accounts, automatically generating balance sheets, profit and loss statements, trial balances, general ledger reports, journal entries, accounts receivable and payable summaries, cash flow analysis, inventory valuation, and inventory summary reports. Sales invoicing supports recurring schedules, customer payment tracking, estimate-to-invoice conversion, and configurable GST/VAT tax rates. Purchase invoicing handles vendor bills with expense categorization for payroll, rent, and operational costs. The inventory module tracks stock levels using FIFO and average cost methods, automatically adjusting quantities on every sale or purchase and providing reorder alerts. Multi-currency accounting converts transactions at real-time exchange rates and consolidates them under customer or vendor profiles with detailed currency reports. The platform deploys via Docker Compose with multi-tenant isolation giving each organization its own separate database, requiring as little as 2GB RAM for the complete production stack. A headless REST API with Postman collections lets developers embed the accounting engine into external applications for programmatic transaction management. Role-based permissions control access for team members and invited accountants across organizations. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.

With 7,400+ GitHub stars, 280+ contributors, and 99 releases spanning 15 years of active development since 2011, Dolibarr is the modular ERP and CRM platform that scales from freelancers tracking invoices to manufacturing companies managing full production workflows — all within a single PHP application requiring only a web server and database. Enable exactly the modules your business needs: CRM with leads, proposals, and online contract signing; invoicing with customer and supplier management, credit notes, and SEPA direct debit; double-entry accounting with bank reconciliation and margin analysis; stock and warehouse management with barcode scanning, batch and lot tracking, and product variants; bill of materials and manufacturing orders with workstation scheduling; HR with employee records, leave management, expense reports, recruitment pipelines, and timesheets; project and task management with shared iCal calendars; and a ticket system with integrated knowledge base for customer support. TakePOS provides a touch-optimized point-of-sale interface for retail shops, bars, and restaurants with floor and table management, QR code self-ordering, automatic stock decrements, and Stripe terminal integration. Payment processors connect via PayPal, Stripe, and Paybox. The marketplace offers over 1,000 third-party add-ons, and the low-code Module Builder enables custom extensions without programming. Deploy via the official Docker image with MariaDB, DEB and RPM packages for Linux, or manual installation on any PHP-capable server. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPL-3.0 licensed.

Roughly 40 integrated business apps forming a full ERP: Odoo's open-source suite runs companies end to end. The Community Edition, licensed LGPL-3.0, ships roughly 40 apps covering CRM, sales, invoicing, basic accounting (journals, chart of accounts, taxes, reconciliation), inventory and warehouse management with multi-step routes, manufacturing with BOMs and work orders, purchasing, project management, timesheets, HR, a website builder, and eCommerce. Each app works standalone, but they share one PostgreSQL database and one data model, so a confirmed sale updates stock, triggers procurement, and posts invoices without integration glue. The modular design means you enable only the apps you need and extend with 40,000+ community modules from the Odoo app store covering nearly any vertical requirement. Inventory supports multi-warehouse stock, reordering rules, and lot and serial tracking with barcode-ready operations; manufacturing ties BOMs, work orders, and work-center routing directly to sales demand and stock levels; and the website builder sells straight from your product catalog with payment provider integrations. You can start with just CRM and invoicing on day one and switch on inventory or eCommerce later - new apps integrate with existing data instantly because the schema is shared. The server is Python with an XML/JavaScript view layer, and because data lives in plain PostgreSQL there is no proprietary format: you can query, back up, migrate, and extend business data directly, with unlimited users and no per-seat licensing - where enterprise ERP pricing is per user per month, headcount here costs nothing.

With over 37,800 GitHub stars and active development since its first release in 2008, ERPNext is the most-starred open-source ERP system — delivering accounting, inventory management, manufacturing, CRM, project tracking, asset management, HR, and point-of-sale capabilities through a unified web interface built on the Frappe Framework's metadata-driven architecture. The accounting module handles multi-company consolidation, multi-currency transactions, tax templates for GST and VAT, bank reconciliation, and automated journal entries with real-time profit and loss, balance sheet, and cash flow reporting. Manufacturing covers production planning with multi-level bill of materials, work order scheduling, capacity planning, subcontracting, and quality inspection at each production stage. Inventory tracks stock across multiple warehouses with batch and serial number tracing, automatic reorder levels, landed cost calculations, and perpetual inventory valuation using FIFO or moving average methods. The CRM module manages leads, opportunities, and customer communication with email integration, while project management tracks tasks, timesheets, and Gantt-based scheduling with budget controls. Custom applications extend functionality through the Frappe ecosystem without forking the core codebase, and the REST API enables integration with payment gateways, shipping providers, and third-party services. Deployable via Docker Compose or the bench CLI tool with MariaDB and Redis. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPL-3.0 licensed.

Full double-entry accounting on your own server: Manager.io Server Edition runs the same engine as the free desktop edition as a web server, so unlimited users work in unlimited businesses concurrently, with all books on infrastructure you control. The module coverage is genuinely comprehensive - general ledger with a customizable chart of accounts, sales and purchase invoices, quotes and orders, bank and cash account reconciliation, inventory with stock tracking, fixed assets with depreciation, payroll, multi-currency with exchange gains and losses, tax codes for VAT and GST regimes, and the complete reporting stack: balance sheet, profit and loss, trial balance, aged receivables and payables, and cash flow statements. The interface is translated into more than seventy languages, reflecting a genuinely global user base. The licensing model is the refreshing part: a server license is a one-time perpetual purchase, not a subscription - twelve months of updates included, optional renewals after, no per-user tiers, no data limits, and you can downgrade to the free desktop edition anytime, so your books are never hostage. Businesses wanting collaborative accounting behind their own firewall, with data sovereignty and no monthly fees, get exactly that.

Hosting companies that sell VPS plans, game servers, or dedicated machines get a branded storefront, recurring billing, and a ticket desk from Paymenter, running on their own server. A customer browses a category, picks a free, one-time, or recurring plan billed every few days, weeks, months, or years, and shapes the order with select, radio, checkbox, text, number, or textarea options, some of which carry their own price. Prices can differ per currency, and a setup fee is optional. Payment runs through Stripe, PayPal, or Mollie, with tax rates and coupons set from the admin panel. Once it clears, a server extension for Pterodactyl, Virtualizor, VirtFusion, Convoy, cPanel, Plesk, DirectAdmin, or Enhance creates the service. A daily job issues renewal invoices, suspends overdue accounts, and terminates long-overdue ones. The customer portal covers services, invoices, and tickets in 24 languages, and tickets accept replies by IMAP email piping. Staff work with roles, audit logs, email logs, and notification templates, while API keys and OAuth clients connect outside tools. Optional extensions add an affiliate program, announcements, and Discord alerts. Moving over from WHMCS takes one built-in command that imports clients, products, services, tickets, and invoices from a copy of your database. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Why export timesheets from one tool, manage Kanban tasks in a second, and copy billable hours into a third just to send a client invoice when TimeTracker handles the entire agency workflow in one self-hosted platform? Start a persistent server-side timer from any browser or log hours manually using saved templates, bulk entry forms, and automatic idle detection. Project managers organize deliverables across drag-and-drop Kanban boards, Gantt timelines, and threaded task comments while monitoring real-time project budgets and cost burn rates. A built-in CRM tracks client contacts, lead scores, and sales pipeline stages before work even begins. When billing day arrives, you convert unbilled hours, reimbursable receipts, mileage logs, and per diem allowances directly into branded multi-currency invoices without double-billing a single minute. Finance teams can customize PDF invoice layouts, automate recurring billing schedules, and transmit EN 16931 compliant electronic invoices via Peppol or embedded ZUGFeRD/Factur-X XML. Interactive analytics dashboards and scheduled CSV or Excel exports give every stakeholder complete visibility into billable utilization. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPL-3.0 licensed.

From a freelancer logging billable hours to companies with hundreds of users, Kimai scales professional-grade open-source time tracking - a Symfony/PHP application without the per-seat pricing of Harvest or Toggl. Tracking is flexible by design: run multiple concurrent timers, use punch-in/punch-out mode, or enter times manually, organized by customer, project, and activity with tags, and priced by user-, customer-, or project-specific rates. The billing pipeline is where Kimai earns "professional grade": generate invoices directly from timesheet data with configurable templates (DOCX, ODS, XLSX, PDF), entry grouping, and invoice-number generators, while an export flag locks billed records against editing and excludes them from future invoices - the audit-safety detail spreadsheet workflows never get right. E-invoicing supports EN 16931, XRechnung 3.0, and Zugferd/Factur-X. Enterprise controls come standard: SAML and LDAP login against Google Workspace, Azure AD, or Authentik, TOTP two-factor auth, customizable role permissions, and teams that scope customers and projects to departments. Money and time budgets alert before overruns, advanced reporting slices recorded time by any dimension, and an extensive JSON API plus a plugin marketplace (expenses, approvals, and more) integrate it with existing infrastructure. Over 30 translations, multi-timezone, AGPL-licensed.