I wanted to clarify whether I can avoid underpayment penalties using the safe harbor rules given my income timing this year.
So far, my tax withholding will fall short of the 110% safe harbor threshold by about $10,000. However, my income was very irregular this year, with roughly 45% of my total income earned in the last quarter (September–December).
Given this, I wanted to ask:
Can I make a single Q4 estimated tax payment of $10,000 to cover the shortfall and still avoid penalties?
Does the fact that a large portion of my income was earned in Q4 allow this even though earlier quarters were $0?
