The custodian of my 401k failed to deduct the 10% withholding that I had requested to be taken from my year-end RMD. I left a message for them regarding this error late Dec. 29th and received an apology on Dec. 30th for receiving "incorrect information" from their representative and stated that nothing could be done. I wrote to the HR department of my former employer about this issue. I was later contacted and told that the call log of my request was going to be reviewed. I was again contacted and they admitted that I had made the request and was told that they were working on a resolution. After several more days, I was told that there was nothing that could be done as the Dec. 31st deadline had passed. What can I do if I find that their error has caused an underpayment of my taxes when I file for 2021?
