<p>You will get a letter in the mail acknowleging receipt of your app -- and it also gives you an ID number that allows you to make changes/additions to your app.</p>
<p>This is from the UC site:
"It is important that applicants complete the Academic History thoroughly and accurately. Students should use grade reports, transcripts and the high school's UC-certified course list; they should not work from memory. Any information that changes after the application is submitted should be reported immediately to the admissions office at each campus to which the student has applied."</p>
<p>It's best to call them. Someone said in 3-4 weeks, they will reopen your applicationa and you can add things. I called UCLA and they said something to this effect but it's best that you call them yourselves. Each campus is different.</p>