So what still confuses me, If I make a single massive estimated payment at the end of the year, then would the IRS care if I my withholdings were way to little throughout the year? How would they know as long as I was good by Dec 31?
I never knew about Schedule Al since I never had a penalty to worry about. But my income is becoming more uneven and unpredictable with time. I understand I can make quarterly payments, I just don't understand why I can't just "square up" at the end of the year.
