I got a 12c letter in the mail from the IRS and have lost it, So i dont know what i need to do to fix my return. Is there anyway to access my 12c letter online or request a new one.
IRS says:
"view notices by logging in to your Online Account with IRS."
You may find the notice posted there.
If you don't have an account you can create one.
If IRS adjusted your tax return, there is nothing for you to do except pay the amount due.
If you did not pay eventually you will get a second bill.