A superseding return is a return filed subsequent to the originally filed return but filed within the filing period, including extensions.
The IRS considers a superseding return as the original filing, because the return takes the place of any other return previously filed during the filing period, including extensions. If you're filing a subsequent return after the filing period, including extensions, you need to file an amended return.
To mark a Form 1120 return as superseding in UltraTax CS, go to the 1120 screen in the General folder and enter
in the Superseding returnA superseding return doesn't replace any previous electronic funds withdrawal payment requests. If you include a payment request in both the original and the superseding return, the amount is withdrawn from the account twice.
An amended return is a subsequent return filed after the expiration of the filing period (including valid extensions). Amended returns are included in the electronic file.
If you needed to file the original return electronically, you also need to file the amended or superseding return electronically. This applies to the current and 2 prior tax years.