Did you file a joint tax return, and you both had W-2s?
What probably happened is that you entered your W-2 and your spouse's W-2 as if
they were for the same person, instead of one for you and one for your spouse.
When you first start to enter a W-2 in a joint return, you have to indicate
whose W-2 it is. The W-2 summary screen ("Here's your W-2 info")
shows which one of you each W-2 was entered for. The program alerts
you of the excess if this happened and asks you to verify that the W-2s are
entered correctly. If you don't make the
correction at that point then sadly the
error is yours. See screen shot for
what the warning screen looks like.
You both had Social Security tax withheld
from your pay. The maximum Social Security withholding has to be calculated
separately for each person. When you enter both W-2s as if they were for the
same person, it makes it look like that person had too much Social Security tax
withheld. The amount that appears to be excess Social Security tax goes on 1040
line 71. If you had entered each W-2 for the correct person, TurboTax would
have seen that there was no excess Social Security tax, and it would not have
put anything on line 71.
You received a refund of the excess Social
Security tax shown on line 71 of your tax return. But because of the error
entering the W-2s, it was not really excess and you were not entitled to that
refund. So now you have to pay it back.
And you better check
your 2017 return line 71 and see if it
happened again. If you transferred from 2016 it would still be wrong. Then for
next year 2018 better not transfer or delete all the w2s and enter them as new
ones to keep the error from continuing.
Another less
common error on the box 12 of the W-2
... also a date entry error by the user which the program would not consider it
an error and would not flag it ...
check your box 12 on each actual W-2 form in your tax file: a code
"A" or code "M" with a $$ amount may also affect your line
71 value.
