<p>Different institutions have their own rules. At Cal, the ceiling is 130 units for those pursuing a single major, and 136 for those pursuing a double. As a transfer, you are allowed 4 semesters (5 if you have two majors) of unrestricted enrollment. This means that so long as you havent gone past 4 semesters, you can enroll in as many units as you want and the unit ceiling will not apply (you can go past 130 units). If you finish 4 semesters however, and you are still not finished at Cal, then the unit ceiling will apply and thus, you can continue enrolling there until you hit 130 units, at which point a block will go on your account and you will not be able to register anymore.</p>