Doubts about tax rules

Hello how are you?
I have a question regarding the tax rules, since when creating the tax rule and adding it to the third party in its configuration, it only allows me to take the first line of the tax rule

For example, as can be seen in the image, this is how the tax rule is configured, but when creating an invoice with this configuration, it only takes the first line, and not the two tax lines, is it normal? Or am I skipping some configuration?

Yes you can replace only one tax by another.

It wil be great if you can share what you want to achieve with the tax line so we can give proper indications.

I have a third party that I must make the supplier invoice, and the product in its accounting category, has a tax configured, since this product is normally bought with tax, but with this third party there is something special, it is that he handles different taxes Due to its tax status in Colombia, therefore, the invoice must be made with two taxes (as shown by the tax rule), but when it comes to making the invoice, it only brings me the first line of the tax rule

Image of the configuration of the accounting category of the product:

Image of the tax rule for that third party:

Image when bringing the product on the supplier invoice:

As I said this is not how tax rule works.
Now I remember I had already such discussion about something similar: Update unit price + tax rules - #2 by ced
So for me it is still the same solution that should be implemented (in a module) by adding extra taxes as substitution.

Normally what we do is create a tax rule that does two steps:

  1. Repalce the original tax with the first tax.
  2. Have another line that adds another tax (you can achieve that by having and empty group on the rule).

If you create the tax rule this way it should work.

Hope it helps!

This design really depend of the kind of taxes because the second tax added should not be linked to the product at all.

For me we need a detailed explanation about what are exactly those taxes:

In Colombia there is a box called Industry and Commercial Withholding (Rete ICA) which serves as an advance payment to deduct the payment of the Industry and Commerce tax (ICA) annually. This box is depending on the economic activity of the company that makes the purchase and is a municipal tax.
For more information about this collection: RETEICA. Qué es el Reteica. Como se calcula y se contabiliza. Cuando se retiene. Explicación Ejemplo | Videofinanzas.

In this case, the tax rule is created with 2 tax lines, since the product that is purchased from this third party in its accounting category has a tax (2.5% for taxpayers) because it is normal to apply this tax , but with this third party there is something special, he is not a taxpayer, therefore in Colombia for non-declarants the 3.5% percentage is used, said tax I placed to replace the rule, but additional, I as a buyer can withhold ICA (industry and commerce box), but I cannot assign said tax in the product category because it is only assigned to special third parties.

What is a box?

I do not understand.

Sorry, but here you explain how you try to configure Tryton for this but what we need to understand is an explanation about what is this thing?