@DoninGA- thank you for the clarification. So, CA Tax authority sent me a past due tax notice for ~ $800 because they didn't have a return on file. When I am filing the return now, the tax due is $1400. Should I only send them a remaining amount of $600? If yes, where do I state on the form that I have paid $800 for the 2018 taxes already , but in 2022. I don't want to send them a check for $1400 when I already paid $800 in 2022. that's my confusion and seems like for the Federal taxes, as you rightly said, nothing needs to be done for the 2018 return, but modify on the 2022 return.
