7 Best open source billing software

Top 7 Open Source Billing and Invoicing Software for Small Businesses

In the fast-speed world of business, finding billing software can be challenging. But what if there is a solution that not only fulfills your needs but also provides you the freedom and flexibility to modify your billing system? 

That’s exactly where an open source billing software comes in. But, there are plenty of options and people often end up choosing the wrong one. That’s why we’ve done the research and compiled a list of the best open source billing software. 

In this article, we will cover the top 7 open source billing software and highlight their key features. 

So without further delay, let’s jump in!

What is an open source billing software?

The billing system is an application or software that is used to automate and speed up billing processes and payment services. It helps to send and generate invoices, track online payments, customer information or services and handle billing-related tasks for businesses or organizations efficiently. 

As the name indicates, Open source billing software is an open source product for billing and invoicing. They may also include features like payment tracking, client management, analysis, and many more.

Although these features can vary based on software functionality, the key features are:

  • Ability to generate customized professional invoices and add itemized billing and due dates
  • Features to easily manage subscriptions, track expenses, and refundable costs
  • Easily get an insight into financial transactions
  • Reports to analyze business performance and customer activities
  • Supports popular payment methods and receives online payments securely
  • Storage for keeping your client details, and tracking communication history
  • Track user payment status and send reminders to clients automatically 

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Why do you need an open source billing and invoicing software in the first place?

Searching for a billing and invoicing solution that aligns with your business? 

Whether you’re a small or large business, open source software can modify the way you want to handle your invoices. Let’s dive into the reasons that make it an essential tool for your businesses:

  • Cost savings: Cost-effectiveness of an open source billing and invoicing software make it a primary option for every business. It assists businesses to save money on overall costs.
  • Flexibility and scalability: Open source invoice software is made to be both scalable and adaptable in order to support your growing operations, you may quickly modify the program, interface it with other systems, and add or delete features.
  • Community support and collaboration: You can access a lot of information, get support, and collaborate with others to enhance software functionality and development.
  • Transparency and security: With open source invoice software, you can review the source code to look for any potential deficiencies and security problems. The transparency of open source software often leads to more rapid bug fixes and security patches.
  • Freedom from a single vendor: You will not be tied up to a specific vendor by using open source software. This reduces vendor lock-in and gives you the freedom to switch to continuous improvement and innovation. 

Overall, whether you’re a small startup or a large enterprise, open source software can revolutionize the way you handle your invoices. And these advantages make it an attractive option for businesses for reliable and customizable invoicing solutions.

Factors to consider when choosing open source billing software:

With so many open source invoice systems on the market, choosing the right one can be difficult. Each invoice software provides unique factors that can help to boost your business. 

But you can’t afford to buy all of them, right?

We always recommend, considering your company’s requirements and picking the option that best fits your requirement. Here are some key factors to consider when selecting the best open source invoice software: 

  • Scalability and integration capabilities: An open source software needs to scale with your business growth and integrate with other essential tools such as CRM, and payment gateways to smoothen your day-to-day operations.
  • User interface and ease of use: Invoice software should be easy to use to navigate for you and your team. The invoice software you’re going to use should have a user-friendly interface that helps you to set up easily and manage your invoices.
  • Reporting and analytics features: It’s essential to have reporting and analytics tools to get an insight into financial performance. These abilities can help you to make wise and informed decisions.
  • Documentation and community support: Make sure to choose an open source invoice software that comes with dedicated support and available documentation for smooth implementation.
  • Security and data privacy: Verify that the software meets industry security standards and protects your sensitive financial data. Look for features like encryption, access control, and regular software updates to ensure data privacy and protection.

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7 best open source invoicing and billing software

Sending invoices is vital for sustaining your small business, regardless of your reasons for starting it. Timely payments are essential for maintaining business continuity. While commercial invoicing tools exist, open source alternatives offer greater versatility. 

Now let’s take a closer look at seven open source invoicing tools that are suitable for freelancers and small businesses:


Freshbooks is a complete open source billing software for small businesses. With this software, you can manage all financial activities and create, modify, and send professional invoices within a few clicks. It’s a SaaS and cloud-based invoicing tool that works with all of the top website builders as well as WordPress and CRM systems.

freshbooks invoicing and billing software

With the Freshbooks automation system, you can send reminders to your clients about their due payments. Additionally, Freshbook securely charges your customer’s credit card for recurring payments and sends an alarm to both you and your clients.

It is suitable for small businesses, freelancers, creators, and consultants.

Key features of Freshbooks:

  • You can create and customize professional invoices that align with your brand
  • It provides multiple secure online payment gateways for the client’s convenience
  • With Freshbooks, you stay connected with your businesses from anywhere
  • You can customize your invoice software templates, add or remove features
  • It helps you keep track of payable hours with time-tracking features
  • You can track and categorize expenses and attach receipts for accuracy
  • It provides detailed financial insight with complete reports and analytics
  • Efficiently manage client, and contact lists and track communication history

Freshbooks pricing: 

  • Lite: 8.50$ per month
  • Plus: 15$ per month
  • Premium: 27.50$ per month
  • Custom pricing

Invoice Ninja

Invoice Ninja is a powerful open source billing software that primarily offers invoicing. However, it’s actually full of a variety of features. With these functionalities, you will receive a ton of benefits without paying anything(including excellent customer service)!

invoice ninja invoicing and billing software

It provides customizable invoice templates, multiple currency support, and integration with a popular payment gateway. Along with these, you can additionally take advantage of special functionalities like listening commands and a Buy Now e-commerce button. 

Key features of Invoice Ninja:

  • You can automate your billing process and eliminate errors while saving time
  • Helps you customize invoice templates to reflect your brand identity
  • Supports various billing methods such as hourly rates or subscriptions
  • It has a feature that will let you connect Excel, Word Docs, and more
  • Seamlessly integrate with popular payment gateways for secure transactions
  • It helps you to see insights with comprehensive reporting and analytics features
  • Efficiently manage client information and communication history
  • Support to serve international clients with multi-currency and multi-language
  • Billing data is secure and protected with strong privacy measures

Invoice Ninja pricing: 

  • Free plan available
  • Ninja Pro plan: $10 per month
  • Enterprise plan: $14 per month


InvoicePlane is a self-hosted open source billing software that offers invoicing, and payment tracking features. It supports multi-user access and provides an option for regular invoices and automated reminders.

invoice plane invoicing and billing software

By using InvoicePlane, you can implement CRM tools for customer management. Moreover, you can include details about your client’s contacts and create notes about each customer. For a truly personalized customer experience, you can customize your invoice platform by selecting themes. 

Key features of InvoicePlane:

  • Maximize revenue and efficiency through data analysis and optimization
  • Valuable billing data insights for data-driven decision
  • Easy integration with flexible API for smooth connection
  • Regular updates, bug fixes, and ongoing support 
  • Integrated with a popular online payment gateway
  • Accurate time tracking and billing functionalities
  • Multilingual interface with 23+ language
  • Supports one-click online payments
  • You can customize it to make sure it fits all your needs

InvoicePlane pricing: 

  • Free


BambooInvoice is lightweight open source billing software designed for simplicity and ease of use. If you are an entrepreneur, it’s an ideal open source invoicing and payment solution provider.

bambooinvoice invoicing and billing software

Additionally, you can conveniently create and modify invoices while organizing them by the assigned invoice numbers. It allows you to generate professional-looking invoices and records. 

Key features of BambooInvoice:

  • Offers a user-friendly interface for easy navigation and usage
  • Effortlessly create and edit invoices
  • Appropriate email and PDF generation for seamless sharing with clients
  • Integrated with online payment providers
  • Customization options based on invoicing needs
  • Created with current coding standards to keep things available
  • Available in 10+ languages, including French, English, Spanish, German, Italian

BambooInvoice pricing:

  • Free

Fluent Forms

Fluent Forms is an open-source form builder plugin for WordPress. It is suitable for businesses and individuals who want a flexible payment and invoicing solution within their WordPress site.

fluent forms plugin

You can use Fluent Forms as an invoicing software with the help of Fluent Forms PDF and payment collection. It offers a drag and drop features to create customizable templates and integration with popular payment gateways like PayPal, Stripe, Razorpay, Mollie, etc.

Key features of Fluent Forms:

  • Custom invoice form creation using pre-built templates and elements
  • Easily integrates with WordPress websites
  • You can automate your invoice process, reduce errors and save time
  • Conditional logic to create dynamic fields based on user inputs
  • Integration with payments gateways like PayPal, Stripe, and Authorize.net
  • Proper email notifications and PDF generation for sending invoice notifications
  • Regular updates, bug fixes, and continuous support
  • Properly manage customer information and contact history

Fluent Forms pricing: 

  • Single site license: $41 per year
  • Agency license: $90 per year
  • Unlimited license: $139 per year

Sliced Invoices

Sliced Invoices stands out as the leading invoice plugin for WordPress that is popular for creating great quotes and invoices easily. It is the ultimate invoicing solution for businesses who want to generate invoices directly on their WordPress website with its exceptional flexibility, and functionality.

sliced invoice invoicing and billing software

This amazing plugin offers you a lot of features, allowing you to customize invoice templates according to your preferences and information for offline payments. With this plugin, you will get the opportunity to export invoices as CSV files, making data management more accessible.

Key features of Sliced Invoices:

  • Simplify accounting with complimentary tax extensions
  • Effortlessly export invoices as CSV files
  • Thoroughly track and report on invoices
  • Seamlessly process payments via PayPal Express Checkout
  • Invoice in your preferred currency
  • Craft custom invoice templates from scratch
  • Conveniently customize offline payment information
  • Choose from a selection of ready-to-use invoice templates
  • Set default due dates for projects

Sliced Invoices pricing: 

  • Freelance bundle: $79 per year
  • Business bundle: $179 per year
  • Agency bundle: $299 per year


OpenSourceBilling is a powerful open source invoice software solution that is designed to simplify invoicing process for businesses. It provides various functionalities that will help you to generate professional invoices track payments, and monitor financial data effectively.

OpenSourceBilling invoicing and billing software

One of the key features of OpenSourceBilling is its user-friendly interface, which is easy for both beginners and experienced users. With this, you can create custom templates and customize invoice elements like logos, colors, and formatting for ensuring the professional look of your brand.

Actually, OpenSourceBilling is specially designed for telecom and hosting service providers who require a strong billing system for fulfilling recurring billing structures. 

Key features of OpenSourceBilling:

  • You can customize the software to match your unique billing needs
  • Allow you to connect with payment gateways and third-party services easily
  • Simplify recurring billing, invoicing, and payment reminders
  • Supports multi-currency and multi-language to operate globally
  • Gain insights into billing operations for informed decisions
  • Saving money with free, license-free usage
  • Regular updates and community support for data protection
  • Get support for ongoing development

OpenSourceBilling pricing: 

  • Free

Our recommendation: Freshbooks

Oh, we’ve reached the most challenging part of this blog!

When there are so many amazing choices, it’s challenging to make a decision. While we’ll suggest one that we think is good from our point of view. Keep in mind that you should make your choice based on the features that are important for your business.

After comparing several popular open source billing software we recommend Freshbooks as a top choice.

Freshbooks provides a user-friendly interface, good features including an automation system, a cloud-based tool that works with all website builders and CMS platforms including WordPress, advanced reporting, and many more.

Plus, it’s suitable for all types of businesses including small businesses and their pricing is remarkably affordable —starting at just $10 per month and also you can also use their free version!

However, we would recommend that you thoroughly evaluate all available options and select the one that best aligns with your specific requirements.

In order to maximize the success of your business or smooth your invoicing system, whether you choose Freshbooks or another open source invoice software, carefully evaluate the features, pricing, and support. We wish you all the best!

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