After you file

Thank you for the reply, I've been self-employed for several years but I always struggle with Setting aside the right amount. I'd prefer to withhold more than I need. In the past, I've tried automated banking with qaptal but even that was too tempting. I know that I have the option of setting up " Backup tax withholding" (automatically sets aside 24%). I'm just wondering if there are any negatives this other than not receiving interest.