Sorry if this has been asked before, but how late would be too late to update college applications for regular decision? What about early action/decision?
Also, if you apply early and get deferred, you would still be able to update your application for the regular round, right?
You don’t get to “update your application”. You can send an email update to admissions at any time before decisions come out after sending your app. For example, if you win a competition or an award, you could email that update and ask them to please consider it as part of your application.
^Correct, once you send an application, you are not going to be able to change the application itself. You can send updates or corrections to the admissions office of the college and request those be added to your file. As to timing for those, it varies and colleges do not usually state any specific end date for sending updates and it can actually vary according to the student – once they start reviewing files and making decisions (a process that itself can take a long time to get through all the applications), updates may be ignored for the purpose of making an admission decision if received after a decision on a particular file has already been made. Also, what can be sent may be limited, e.g., for ED or EA, some colleges require all testing to be done by Oct and thus sending your Nov SAT test score, even if received before the final ED or EA decison is made, will not help.
As to deferals from ED/EA to regular, you usually can update with new information, including new test scores, as long as the new information is sent in time pursuant to the college’s regular admission application schedule.
OP asked:
“Also, if you apply early and get deferred, you would still be able to update your application for the regular round,
right?”
It depends on the school. Some schools will NOT reconsider an application during regular admissions, even if a new ACT/SAT score is available. Read that school’s policy carefully.