Which entity is required to file a corporate tax return?

An S-Corporation is a specific type of corporation that allows income, deductions, and tax credits to be passed through to shareholders for federal tax purposes. This means that the S-Corporation itself does not pay federal income tax; instead, its shareholders report the income on their personal tax returns. However, the S-Corporation is still required to file a corporate tax return, specifically Form 1120S, indicating its income, deductions, and other relevant tax information.

In contrast, a sole proprietorship, LLC (if treated as a disregarded entity), and general partnership typically do not file a corporate tax return since they may not exist as separate taxable entities. Instead, their income is reported on the personal tax returns of the owners or partners, reflecting a different taxation structure. Therefore, the requirement for filing a separate corporate tax return is unique to S-Corporations within the provided options.