 <p>I would like to bring some more precision. At least, for the most recent version of Symfony (2.1), the correct symtax (documented on the API) is:</p> <pre><code>&lt;?php public FormBuilderInterface createNamedBuilder(string $name, string|FormTypeInterface $type = 'form', mixed $data = null, array $options = array(), FormBuilderInterface $parent = null) </code></pre> <p>It is important because you can still pass options to the FormBuilder. For a more concrete example:</p> <pre><code>&lt;?php $form = $this-&gt;get('form.factory')-&gt;createNamedBuilder('user', 'form', null, array( 'constraints' =&gt; $collectionConstraint, )) -&gt;add('name', 'text') -&gt;add('email', 'email') -&gt;getForm(); </code></pre>