The main thing in this strategy is that your estimate is pretty close to the amount owed. So you may overshoot or undershoot, but likely by a pretty small amoun

The main thing in this strategy is that your estimate is pretty close to the amount owed. So you may overshoot or undershoot, but likely by a pretty small amount, which is likely to make the difference owed small. I guess it could be considered a cost of filing taxes.