<p>How many are allowed?</p>
<p>How many are advised?</p>
<p>You can take up to 3 tests. They are each just under an hour, so taking all three takes about as much time as the full SAT I. You register for whatever tests you want when you sign up for your test date, but keep in mind that’s very flexible - when you show up at your test center the morning of the test, you can take fewer tests than you originally signed up for, more tests, or different tests. If you take fewer, I think you forfeit the money for the skipped test, and if you take more, you get billed for it later.</p>