I live abroad so I must mail in my return. I was about it mail it when I realized a mistake on my return. Do I need to do "amend" since I have not mailed it out yet?

[Opus 17]

It is not an amended return.  But, if your return is considered “filed” (by mail) by TurboTax, you may be unable to make changes without using the Amend button.  

I would try these steps in order.

1. Try and change your return and reprint it without using the amend button.  

2. If that doesn’t work, contact support and see if they can mark it “unfiled” so you can change it and “file” it again.  You may need to use Facebook or twitter to contact them since they won’t do an overseas call back. 

3. Make the amended return with the changes.  Since an amended return is a complete copy of your tax return plus the 1040x cover sheet, you can discard the cover sheet and mail the rest and it will be identical to an original return.  If you do this, download a copy of your tax data file to your computer for safekeeping (before and after amending) in case you need to really amend later.