What the % shall I use in estimating tax prepayment from stock gains? What if the sale is in the last quarter?
1. Do I need to prepay state tax as well?
2. Is it enough if I assume 15% tax on capital gain and 30% on short term gain?
3. What if the sale happens in Q4 (or more extremely, nearly year end)? Since I would have no time to prepay, will I be charged penalty?
Thank you very much.