Open4Tax is an open source provider of knowledge on sales tax, in particular the role of technology to facilitate sales tax collection by open source e-commerce platforms like Ubercart, Drupal Commerce, Zen Cart and others.

Our sales tax directories are made up of products/technologies which we believe will help e-tailers collect sales tax correctly. We do not charge manufacturers to be included in our directories - we do not sell any of their products - we publish our directories because we think they are a helpful and safe way for you to learn what is possible!

If you are a finance professional advising eCommerce web sites we encourage you to participate in our forums.

Please read our content to better understand how you can comply with today’s sales tax requirements.

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All content on our site is moderated. We limit our contributors to recognized sales tax experts and e-tailers willing to share their experiences implementing sales tax solutions!

As a guest, by reading our postings!
As a contributor, by sharing your thoughts!
As a developer, by contributing technology!
As a sponsor, by advertising on our site!


Millions of individuals, private businesses, and public programs are impacted by sales tax collections.