FIRST, we are talking about your 2017 refund, which you received in 2018.
Is the refund taxable on your 2018 return? NO-not if you took the Standard Deduction on your 2017 return.
Did you take the standard deduction on your 2017 return? I don't know, I think you say "Yes" you did, but when the program asked, you said No, you took the standard.
Do you need to know where to find this information? It is on line 40 of the 2017 1040. You need to look at this line to see if you itemized or took the standard deduction. Also, if you itemized, you would have had a 2017 Schedule A.
OK, now I think you are saying that you DO need to claim the refund, but your not sure if you already did claim the. refund on your original 2018 1040.
To see if you claimed the refund already, look at your 2018 Schedule 1 line 10.
JUST SCHEDULE 1 LINE 10.
If this line has the refund reported, you already claimed it. If not you didn't.
(schedule 1 line 10 does flow to the 1040 line 6 but so do other things, so the amount won't be the same. Just look at schedule 1 line 10)
I hope this makes sense. If not, please tell me what exactly you are trying to look at or find at this point.
