Four Open Source Invoicing Apps Worth Checking Out

Invoicing is one of the necessary evils for freelancers and small business owners. It's a pain in the neck to bother with but, on the other hand, it's always nice to get paid. Here are four open source invoicing applications that make the job a little easier.

Argentum - This full-featured invoicing app lets you manage multiple clients, along with their contact, bill, shipping, and contract information. It supports multiple currencies and has a built-in currency converter. Argentum has all kinds of different add-on modules for emails, budgeting, and live timers, along with an API so you can create customized modules to suit your specific needs. Argentum is free to download and use on your server, or the company will provide managed hosting for $10 per month.

BambooInvoice - Simple and easy to use, this invoicing software sits on your server so you can control all your data securely and privately. It's highly customizable, including the ability to upload your own logos and images. BambooInvoice lets you manage your customer invoices at a granular level -- add invoice and client notes to each file, itemize work performed, include tax information, and more.

Simple Invoices - This Web-based invoicing system makes billing your customers a breeze. It's accessible from anywhere and has a batch of features that should satisfy all but the most demanding users. Invoices you created can be emailed right from the app, exported to one of several formats including PDF, plain text, or Excel, and the app supports multiple invoice types as well. You can even use Simple Invoices to create receipts, quotes, estimates, documents, and many other kinds of forms contractors find themselves creating for clients.

siwapp - This invoicing system was designed to be intuitive and fast to use. It has support for multiple invoices, clients, and will automatically generate invoices on a periodic basis if you want it to. Siwapp can be accessed online, but you can easily make backups to your own hard drive any time. If you're looking for an invoicing app that's straightforward without a lot of bells and whistles to get in the way, swiapp might be just what you're looking for.