The Simplified Method is when you claim the FTC without filing form 1116. the penalty for doing this is you lose the right to claim any FTC carryover. Under the SM, if you are single you can claim up to $300 of FTC ($600 if married) on passive income without filing the form. The credit is also limited to your tax liability. so if you have $300 of FTC, a tax liability of $200, and elect the SM you reduce your liability to $0 but lose the $100 carryover. it would seem that since form 1116 was not included in the filed tax return you have no usable carryover from 2017.
