Part IV - 2018 Estimated Tax payments ..... error in EFTPS Confirmation Number (odd but this is a 2019 Form 1120, and they are 2019, not 2018 Estimated Taxes in the Worksheet) .... and I have no estimated tax payments ... this is a C-Corp with NOL c/f

Officer Firm name must be 20 characters or less (name in Worksheet is John) ...

When taxable income is zero, or less than zero, Line 35, Amount owed should be left blank .... (this is the most plausible, but line 35 on page one of return is a calculated figure and is blank in my form)

So, none of the articulated speculative reasons for this error make sense