Can I change from "not need-based" on my app to "need-based"?

<p>In general: my family income is around $180,000, 2 kids (including me, other one is much younger), 1 parent that works. I don't really know what my EFC would be, but am worrying that applying not need-based might have been a mistake...does it hurt to change it on your application? When are most Financial Aid materials due and how long do they usually take to fill? Thank you for any help you can provide.</p>