Forgot to report solo 401k employee contributions after w-2 was already filed. single person s-corp

[Anonymous]

does it matter if I don't report my contributions?  can I add them for 2016 by amending w-2?

[Anonymous]

I don't see anywhere to reply so I'll try it here.  dmertz answered and I appreciate the answer however my box 1, w-2 will change.  What happens to the soc sec and medicare figures. The 941's will no longer match the w2. Help!!

[dmertz · Accepted solution]

Your S-corp must issue a corrected W-2 (Form W-2C) if the original W-2 failed to report employee elective deferrals (code D) or Roth contributions (code AA).  Elective deferrals (code D) should also have been excluded from the amount in box 1 of the W-2.  If the corrected W-2 results in no change to tax liability on your personal tax return, there is need to amend your personal tax return.  However, if the amount in box 1 changes as a result of an elective deferral not being previously excluded, you would need to amend your personal tax return.

[dmertz]

Elective deferrals to a 401(k) are to be excluded from Form W-2 box 1, but not from boxes 3 (up to the SS wage base) and 5.

If you correct what you report in box 1 of the W-2, I believe that you must also correct line 2 of your Forms 941.

I'm curious, though, how you could get line 2 of Form 941 (and box 1 of the W-2) wrong if you were properly withholding elective deferrals from each paycheck and depositing them into the 401(k) within the proper timeframe.  (The Department of Labor requires that elective deferrals from each paycheck be deposited no later than the 15th business day of the month following the pay date.)

[Anonymous]

Unfortunately I deposited contributions straight out of my business account and failed to subtract them from wages paid.  I don't do a normal payroll.