I am too busy with the start of the semester to complete the mandatory immigration check-in steps with OIP-ISSS, would that be a problem?
These should be some of your highest priorities upon entry to the US. Failure to check-in with OIP-ISSS (within 15 days for Transfer students, 20 days for all other students who are new or returning under a new SEVIS ID) could lead to a serious violation of your F-1 or J-1 status, termination of your SEVIS record by the US Department of Homeland Security, and the loss of your lawful nonimmigrant status in the US. For more information, please contact OIP-ISSS via e-mail at oipadm@pobox.upenn.edu or by phone at 215-898-4661.