Applying tax twice and other taxes

The module works like this (maybe is lack of documentation)

- Create a Tax Vocabulary, with these values (i.e.) "10% Tax" and "20% Tax"
- Create one tax for each vocabulary term, in this case, would be logical to create a tax with a 10% and another with 20%, in the tax settings, asign each term to the tax.

When buying, if the product has one of these terms, the tax or taxes assigned in the tax settings are applied, it doesn't work by a "yes/no" basis.

I think we need some more information from nigel as to how he would be attempting to achieve this.
Where and what are you applying the taxonomy terms to? As pcambra said they can only be applied to products.

However, the same tax rate being applied twice to the order is a bug. It happens when the criteria of an order matches both that for uc_taxes and uc_taxonomy_tax (e.g. the product content type, and a taxonomy term).
I've just committed a fix that prevents items being taxed if they have already been done so by uc_taxes.

Thanks
Leon

Try to disable the "product" option in the tax settings, only set the taxonomy.

shouldn't this module override the default uc_taxes? or should I disable it and just use uc_taxonomy_tax?
This module is dependent on uc_taxes.

It also is not possible to override what uc_taxes does. You cannot remove tax from a hook (at least from what I know and tried).

I think what is needed is some clearer messaging on the uc_taxes admin page, as there were also a few people confused by this over on the ubercart forums.
It basically needs to say "taxed taxonomy terms" OR "taxed product types". I.e. if a product matches anything selected in either of these boxes it will be taxed.