Businesses can be structured in many different ways, and the filing requirements will depend on the chosen structure.
Sole proprietors or single-member LLC are required to file Schedule C, which is filed as part of a personal tax return.
Partnerships or multiple-member LLCs are required to file Form 1065 and provide Schedule K-1s for each partner/LLC member
S-Corporations are required to file Form 1120-S, while C-corporations file Form 1120.
If you're reporting your business income on your personal tax return you must also complete Schedule SE for calculation of self-employment taxes. TFX will handle everything for you.