billingcat – invoicing software powered by the speedata Publisher

It has been a while since my last post on this blog. This time I would like to introduce a project that is a bit different in scope but technically closely related to the speedata Publisher: billingcat – an open-source application for invoicing and simple customer relationship management.

What is billingcat?

billingcat is an open-source project that combines two essential tasks for freelancers and small businesses: creating invoices (including ZUGFeRD support) and managing customer data in a lightweight CRM.

The project is currently in the alpha stage and only available in German, but already allows users to create invoices, manage clients, and use their own letterheads for invoices.

Screenshot billingcat dashboard

Connection to the speedata Publisher

Under the hood, billingcat uses the speedata Publisher to generate ZUGFeRD-compliant PDF/A invoices. The Publisher handles the PDF generation, embedding of XML data, and layout rendering.

In the future, billingcat will also use the Publisher for other PDF outputs to take full advantage of its layout and automation features while keeping a simple web-based interface for end users.

Screenshot example invoice

Looking ahead

billingcat is still in its early stages, but the feedback from the first alpha testers has already been very encouraging. For me, this project is also a great example of how the speedata Publisher can be integrated into other systems to produce high-quality document output – even as part of modern web applications.

In an upcoming post, I plan to write about a brand-new feature in billingcat: the Letterhead Editor. It allows users to design their own letterheads and upload custom font files, making it possible to generate personalized layouts without additional coding effort.

More on that soon here on the blog.

More information about the project: billingcat.de
Source code on GitHub: github.com/billingcat