In AR parameters / updates / Tax exempt number requirement I put domestic +EU member states. In tab dialog it says : select the countries/ régions where a tax exempt number is required before making out an invoice.
I do not have a tax exempt number to one Customer, but I manage to post an invoice on this Customer via the project module.
Is it the standard way of Ax ?
Do anyone can help me concerning this setup ?
I would like to do this field of tax exempt number only mandatory for Customer when I want to post an invoice.
When the Tax exempt number requirement is enabled for invoices the check (within projects) should be performed at the time of creating the invoice proposal. You can check if this still works in your environment. If the proposal is created and then this setting will be enabled, AX is not cheching at time of posting the invoice itself.
It is based upon the country code settings of the address of the customer - can you check this is configured correctly?