Getting the user ID of the user who created a taxonomy term
try to do this:


Add a field called 'Author' like a entity reference 
alter the form to prepopulate this field

function customodule_form_alter(&amp;$form, &amp;$form_state, $form_id){
print_r($form_id);  
if( $form_id == 'taxonomy-form-term' &amp;&amp; isset($form['field_author']) ){ 

  print_r($form['field_author']['nid']['nid']['#value']);  
  global $user;    
  $form['field_author']['nid']['nid']['#value'] == $user-&gt;uid;

  }  
} 



I put some print_r so you can debug this code fast.