Have a similar situation with doing two Roth Conversions in 2019. Since there will be a spike in the two quarters that I do the Roth conversions (June and December), am I still able to utilize the Safe Harbor Rule by paying at least 90% of what I will owe in taxes for 2019 in 4 equal quarterly installments in March, June, September and December? Or will I have to pay more in the two months where I am doing the Roth Conversions since there will be an income spike? I have no other income or withholding of taxes for 2019.
