<prompt> Human: I work a full time sales job and want to begin aggressively paying down the credit card debt Ive built up. Ive had one exemption on my taxes since the beginning of the year and just swapped the number to 3 via ADP app. Will I be penalized? If so, why?  <response>: 3 could be fine. The worst that could happen is that you have to write a check come April if you under withhold. Run your numbers through the IRS calculator. 