Confirm only part of certain restrictions

I have this field:

$builder->add('offices', 'entity', array(
    'class' => 'ControlPanelBundle:Offices',
    'property' => 'name',
));

      

        
        
        
      

    

In my form, I only use one field out of all the possible fields for this object Offices

. When I submit it tries to validate all fields. How can I temporarily disable verification only during this time?