Number of reliable exporter showed on the pdfs and xml of customer invoices 

The number of reliable exporter should only be displayed if our customer is part of the European Union. If is not part of this group, this field is not necessary.

This information is obtained from the "c_País" catalog: http://omawww.sat.gob.mx/tramitesyservicios/Paginas/catalogos_emision_cfdi_complemento_ce.htm

1. First of all we need to register the number of reliable exporter in the database. ​Settings » Accounting » Electronic invoicing (MX) » External trade » Number of reliable exporter. 

2. We have to make sure that the countries that are part of the European Union on this catalog also appear in the group of "europe countries" in odoo. Contacts » Configuration » Country group » Europe

3. Finally, if you create an external trade invoice for any client that are part of this group, the pdfs and xml will show the number of reliable exporter.