Thanks for the reply, @dmertz @Opus 17 @rjs! For some more context, here are the numbers of my other W-2 boxes (btw, I haven't submitted the W-2 yet, so I can still correct it.):
- Box 2: 430.20
- Box 3 and Box 5: 13,334
- Box 4: 826.70
- Box 6: 193.34
The mistake I made was I calculated my income tax withholding for Form 941 based on my entire gross pay (without first deducting the 401K contribution from my gross pay). If I had, my Box 2 would have been 0 because I contributed all my salary to pre-tax 401K. I withheld the 7.65% Social Security and Medicare taxes as required.
I thought the maximum 401K contribution is 100% of pre-tax gross pay, which would be $13,334 in my case. So that's the amount I contributed to my 401K. Is the maximum actually supposed to 100% of (gross pay - 7.65% FICA tax)?
To correct my current situation, is it ok if I keep my Form 941 income tax withholding of $430.20 as is (that's what I currently have in W-2 Box 2), and at the same time correct my 2020 401K contribution to be (gross pay - Box 2 - Box 4 - Box 6)? After this correction, my W-2 Box 1 will be the sum of Boxes 2, 4 and 6.
Thanks a lot for your help!
