<prompt> Human: My company has a stock purchase plan that 5 of your after tax income goes into stock at a 15 discount of the lowest price in a 6 month period. Would it be worth it to claim more allowances to increase my after tax income if it means Ill have to pay more at the end of the year? Are there any other downsides to taking more allowances? Im planning to sell the stock right away.  <response>: I will bet you dollars to donuts that its not 5 of your after-tax income but 5 of your gross income, in after-tax non-deductible money. Go check your paystub and I think youll see theyre doing 5 of gross to the ESPP. 