I don't understand? Insufficient with holding, what is that? and how do I know or not know what I have to with hold? I with hold more at both companies when I put my, what's it called W4? or what ever that is to hold back an extra 200 per pay check. Also my income changes, its not always the same so how am I supposed to pay this "tax" up front when I don't know what my income is going to be at the end of the year
