<prompt> Human: Hi everybody,So I do the taxes for an elderly relative. He has significant stock holdings as well as a bunch of other stuff. So every year Ive been looking at the previous years taxes, make a guesstimate on how the income stacks up on the current year, and make estimated tax payments based on that amount. In 2016 my relative was assessed a penalty for not paying enough estimated tax. It was a good year financially. So I just paid the penalty. This despite the fact that the 2014 and 2015 tax refunds which are for about 20K total had not been paid out because of a fraud alert on his file. I finally got some of that straightened out. The 2015 refund is supposed to come soon. No word on 2014 yet. However, I noticed that I paid 2016 estimated taxes in an amount that exceeded 2015 taxes. Can I apply to get a refund on the penalty? Also, is there any kind of good way to estimate tax payments that isnt just guesswork? Thanks for your help.  <response>: Can I apply to get a refund on the penalty? File the appropriate Form 2210 Also, is there any kind of good way to estimate tax payments that isnt just guesswork? Use the worksheets on Form 1040-ES or in Publication 505 