This is just naming convention. Various customer/suppliers are handled differently regarding tax charges, so they belong to various Tax Groups. Just treat the Tax Group as a tax filter which selects removes some taxes defined on items, and not applicable to given customer.
Janusz

This is a nice testimony of the flexibility of FrontAccounting's tax configuration capabilities in managing exceptions.

Scott

It work fine. Good suggestions.
This approach is not usual in Portugal.
FA approach
Tax Group -> Customer
Item Tax Type -> Item

Best approach for Portugal
Tax Group -> Item (because the tax is define by item, not the customer)
Item Tax Type (renamed Customer Tax Type -> Customer (because customer may be tax free)

Now go to Setup -> Item Tax Types and create the following to codes:

Tax23only
Tax06only

And exclude the appropriate tax rates for each.

Then go to your item configuration and assign the appropriate Item Tax Type.

From these instructions, you can understand that the Item Tax Type serves as an exception to the 'general' tax group assigned at the Branch-level.

Hope this helps.

Scott

when i join two rate to 1 group, it will calculate two rates for each item. Example:
Item a:
Price tax
100  23
100  6
Item b:
Price tax
200  23
200  6
I need 1 item, 1 tax. Example:
Item a:
100  23
Item b:
Price tax
200  6

If i set the tax 23 to customer. All item invoiced set 23%.

Any ideias?

Under Setup create two tax rates (Taxes sub-menu) and assign the appropriate values:

Tax23 @ 23%
Tax06 @ 6%

Next under Setup, create a tax group (Tax Groups sub-menu) and ensure the tax rates you just created are associated by 'checking' them:

POR

Next, ensure that you assign the 'POR' tax group to the Branch where-upon you will be shipping to.

Hope this helps.

Scott

I make a invoice for customer Mario with 2 item (a e b)
The tax in incoice should be:
100x23%= 23
200x6%= 12

Total tax : 35

I can do this, with FA?