<p>I submitted the common app to a school a few days prior to the supplement thinking I would finish it on time and, unfortunately, I did not. All other materials were submitted, and I made an account on their admissions site, so I'm not sure how I should go about telling them to "withdraw" my application. Will they do it automatically or should I email them and tell them about it?</p>
<p>Did you try to complete the supplement and it wouldn’t let you? I would still try since you submitted the rest of the application on time. If you’ve just decided not to apply, then do nothing.</p>