@les_rjtt Regrettably, in the situation where there is an overpayment in the first/second quarter (merged in 2020 due to COVID relief), my TT desktop for windows, as of 3/3 morning, is NOT correctly carrying the overpayment to the third quarter, instead carrying a 0 amount. So at least in this particular case, TT is not correctly calculating the tax.
This is highly unusual, so I don't blame you for assuming the calculations and relationships between fields would all be correct, but in this particular situation (overpayment in the first quarter) if TT shows you owing an underpayment penalty, it may not be [i.e. is] calculating the amount correctly. Otherwise you should be fine. [This is all in this one thread because often people posting here are making the assumption you're making and are mystified what's wrong. Really there were two issues--the form being ready for those who need it and then the form calculating inaccurately for a small fraction of those using it. The form is now ready. The calculating problem is still there.]
