If you forgot to include a W-2 with your return that you
have already filed, it may not delay your refund, but unless you file an
amended return to correct your mistake you will be contacted by the IRS for not
reporting all of your income.
Adding the W-2 may increase your refund or it may require
you to pay some money back. Without
knowing your entire tax situation and the amounts that were not reported there
is no way to know how your return will be affected.
When you create and file your amended return, it will take
into account the refund that was shown on your originally filed return. It would be best for you to wait for the
refund and then file the amended return so that the IRS will not be processing
two returns for you at the same time. As
long as the amended return is filed before the April deadline for 2017 returns,
you will not incur any penalties for not including the W-2 on your return.
The instructions for amending your 2017 return will be
available soon. The link below will
update when they become available.
https://ttlc.intuit.com/replies/3288565
https://ttlc.intuit.com/replies/3318732
