Steuernummer was being validated at tax report xml generation. The check was moved to the company form view. Moreover, the field was set visible in the company form view for multivat. It should be a constraint raising when trying to set the steuernummer to the company; there is no point in only checking it at XML generation. task-3809218 closes odoo/odoo#161423 X-original-commit: c8543f716164d9e1f7e5b39908ff9805c9cc53bd Related: odoo/enterprise#60496 Signed-off-by: Olivier Colson (oco) <oco@odoo.com> Signed-off-by: Hesham Saleh (hsal) <hsal@odoo.com>