How to custom theme Inline Entity Form (IEF) - using a .tpl.php file Is there a way to theme the Inline Entity Form (IEF) for example creating a .tpl.php file for that form and just declaring it on the theme's template.php?

I wanted to create a .tpl.php specifically since I want to add in custom codes in the form like, views, a little html, jquery and css.

Any help would be greatly appreciated.
I don't think that Inline Entity form supports that. You could alter the behaviour of the form itself though with

 function THEMENAME_inline_entity_form_entity_form_alter(&amp;$entity_form, &amp;$form_state) {
   // your alters
}