<p>Ok Since i see this question Asked by alot of people (including myself), I called the Collegeboard to confrim The question is
** Can i ADD an SAT Subject test on the test date if i have registered for one?**</p>
<p>*Answer *: yes, and you will only be charged the Extra 8$ per test you add, unless if it is a listening test then you would have to contact the collegeboard before hand.</p>