Investors & landlords
@artg wrote:
However (and I think this is important) our FITW plus the Estimated taxes we've paid are GREATER than 110% of our 2018 tax liability (Line 15 of our 2018 1040.)
Yes, that is indeed important. In that event, you will have no underpayment penalty and should not have to bother with the AI method.
See https://www.irs.gov/taxtopics/tc306
The Other Taxes screen, including Guidance is shown in the screenshot below (in case you are still curious).
