Magento – How to customize Magento Invoice based on GST TAX

Well, finally it was really easy... But in fact I have lost almost one week searching the issue of this problem.

It seems that even if you will precise the tax %, in the tax rules, and you will chose tax class "Normal", the same for the product, it will not add tax to your product. It will without tax.

You have to choose tax class Shipping, for tax rule and product. And after that all works like a charm.

This is most likely due to the Tax Origin not being set correctly (it's probably on its default: US). This is different from the Default Country setting, you can find it at System -> Configuration -> [SALES] Tax -> Origin.

Let me know if it works! :)