If you are "almost positive" that you did not mail the original return (not sure how how you do not know if you took an envelope to a mailbox..) Amending is STILL inappropriate. You only send in a Form 1040X if the original return has been processed. The IRS needs an ORIGINAL return from you. If you have to, start over again and prepare an original return on a Form 1040 (NOT a 1040X) with ALL of your income on it.
But....you cannot start a new online return using TurboTax now, since online tax prep is closed. A new return has to be started on desktop software which must be downloaded to a full PC or Mac.
Then if you want to take your chances on having two different mailed returns sitting in piles at the IRS, take the chance and mail the return that is correct and hope that is the one that gets processed.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
