Form 1120-S U.S. Income Tax Return for an S Corporation can be amended by clicking the Checkbox next to Amended Return, on page 1 section H.
To access this checkbox through the Q&A:
You will need to attach an explanation of changes, and if the income, deductions, or credits changed, then a new Schedule K-1 (Form 1120-S) Shareholder’s Share of Income, Deductions, Credits, etc. must be filed and copies sent to the shareholders.
TaxAct supports the e-filing of amended S Corporation returns. At the end of the Amended Federal Return section, you will be prompted to select either Paper Filing or Electronic Filing.
Note: If you filed the original return through TaxAct, you can create an amended return for free, however, there may be fees for any additional forms required that were not included in the original return.