Utilize your financial knowledge, give your answer or opinion to the input question or subject . Answer format is not limited.

Employer reported ESPP ordinary income on wrong year's W-2
Based on the statement in your question you think it should have been on the 2014 W-2 but it was included on the 2015 W-2. If you are correct, then you are asking them to correct two w-2 forms: the 2014 form and the 2015 form. You will also have to file form 1040-x for 2014 to correct last years tax forms. You will have to pay additional tax with that filing, and there could be penalties and interest. But if you directed them on the last day of the year, it is likely that the transaction actually took place the next year. You will have to look at the paperwork for the account to see what is the expected delay. You should also be able to see from the account history when it actually took place, and when the funds were credited to your account.  or you could just pay the tax this year. This might be the best if there is no real difference in the result. Now if you added the sale to your taxes lat year without a corresponding tax statement from your account, that is a much more complex situation. The IRS could eventually flag the discrepancy, so you may have to adjust last year filing anyway.