Such fiscal positions define an alternate VAT for a specific region. When foreign_vat is set, a country must be set on the fiscal position; it'll be used to know for which tax report the fiscal position must be available as an alternate VAT (in the tax report; see enterprise branch). Note that it is possible to defined several foreign VATs for the same country, as long as they belong to different states within that country.
Note that this new feature is only for FOREIGN stuff; so, when you have to submit a tax report in different regions than yours. For example if you have a Belgian accounting, have French customers, and have a French VAT in addition to your Belgian VAT, to submit a tax report in France. For domestic operations, simply use your the vat field of your company, just like before.
[IMP] account: add country_id on taxes and filter them on invoices
The invoices now compute the country from which they should accept the taxes: it's either the one defined by fiscal_position_id.country_id (if fiscal_position_id is a foreign VAT fiscal position, i.e. it defines a foreign_vat value), or the company's account_fiscal_country_id.
Taxes from other countries are filtered from the view; we don't want them to be available there. There is also a constraint ensuring that. Same goes for tax repartition lines and tags from other countries.
We don't want to mix taxes, tags and foreign VAT fiscal positions from different countries, as it would break the tax report in enterprise. Doing this ensures the tax report can efficiently discriminate the move lines between the different regions whose report they have to appear in.
[IMP] account: add country_id to account.chart.template
This is done so that the taxes are created in the right country, and the fiscal country is initialized in a consistent way when instantiating the CoA on the company.
[IMP] account: print foreign VAT on invoice instead of company VAT if one is defined
[IMP] web: allow forcing company vat on document templates
This is done to allow the use of foreign vat fiscal position on invoices: in that case, we don't want to use the company VAT, but the value of fiscal_position_id.foreign_vat. So, when such a value exists, the invoice simply set the force_vat variable to the right value.
[IMP] base_vat: also validate VAT of foreign VAT fiscal positions
We generalize the code formerly only done for res.partner so that the foreign_vat field of account.fiscal.position can be checked in the same way.
oco-odoo