That makes sense. I guess my confusion results from the IRS ONLY mentioning withholding taxes in Part I of Form 2210. This makes it sound like withholdings are a way to circumvent timely payments. Here is an example:
I get large lump payments from a publisher in Q1 and Q3 every year. These payments vary. Assume that I pay no estimated tax payments and only pay tax via withholdings from my day job. Now towards the end of the year, I substantially increase my withholdings for two months so that I fall within the safe harbor rules listed in Part I of Form 2210. Could the IRS still assess a late penalty even though I followed exactly what they state in Part I of Form 2210?
