I need to amend my 2016 taxes (Federal & California). Should I use my 2016 or 2017 TT software? Note: I've just filed my 2017 taxes. 2016 taxes was filed a year ago.

[fkhalilz]

I have just realized that I have missed 1 expense item (i.e. property taxes worth about $2300 ) in calculation of my rental property income in 2016.

If I amend the 2016 taxes but don't file it (say the refund was not increased significantly), will it be OK?

After amending my 2016 taxes, how will I know if my 2017 taxes (Federal and California State taxes that are already filed) are affected or not and whether 2017 taxes also need to be amended?

When I do my 2018 taxes next year, will the information from my existing 2017 taxes (if not amended) be transferred to 2018?

Anything to worry about?

[PatriciaV · Accepted solution]

Yes, if you need to amend your 2016 tax return, you will need to use TurboTax 2016. Due to tax law changes, each version of TurboTax is specific to one tax year.

When using TurboTax for Desktop, it's best to save a copy of your filed return before you enter any information for an amended return. This ensures that you have the original filed return to use next year, in case you don't file the amended return.

If you do not file an amended return, nothing changes with regard to either 2016 or 2017. 

It's unlikely a filed amended 2016 return would affect 2017 unless you had carryover losses to apply to 2017. In that case, you would also file an amended 2017 return.

Save the final version of your filed 2017 tax return in a safe place (and back up to the cloud or on a flash drive). You will need that file when you begin your tax return next year.