@Carl wrote:
Personal 1040 tax returns have a filing deadline of Apr 15th (normally) while all other types of tax returns (1056, 1120, 1120-S) have a filing deadline of March 15th.
Form 1120 (return for a C corporation) has a filing deadline of the 15th day of the 4th month after the end of the C corporation's tax year. For calendar year corporations, that would be April 15, 2021 for the 2020 tax year, not March 15th.
