A Guide to Federal Filing Requirements for Privately Held Corporations

By James R. Leichter (aka: Mr. HVAC)

An Introduction to Federal Filing Requirements

Understanding the federal filing requirements for various business entities is essential for maintaining tax compliance and avoiding penalties. Whether you’re managing an S-Corporation, C-Corporation, LLC, partnership, or non-profit organization, staying on top of federal tax forms is crucial.

This comprehensive guide covers everything from payroll tax forms to annual reports, ensuring your business meets all IRS obligations.

Discover the key federal forms required for different entities, including monthly, quarterly, and annual filings, along with their due dates and tips for efficient tax management. Dive into the details to ensure your business stays compliant.

Requirements by Business Entity

S-Corporations and C-Corporations


Form 941 (Employer’s Quarterly Federal Tax Return)
Due Dates: April 30, July 31, October 31, and January 31.
Note: While this is a quarterly form, payroll deposits need to be made monthly or semi-weekly, depending on the size of the payroll.


Form 941 (Employer’s Quarterly Federal Tax Return)
Due Dates: April 30, July 31, October 31, and January 31.
Reports federal income tax, Social Security, and Medicare tax withheld from employees’ wages, as well as the employer’s portion of Social Security and Medicare tax.

Form 720 (Quarterly Federal Excise Tax Return)
Due Dates: Last day of the month following the end of the quarter (April 30, July 31, October 31, and January 31).
Required for companies that owe excise taxes.

Form 941 Schedule B (Report of Tax Liability for Semiweekly Schedule Depositors)
Due Dates: Same as Form 941.
Required for employers who are semiweekly depositors.


Form 1120 (U.S. Corporation Income Tax Return) for C-Corps
Due Date: April 15 (for calendar year filers) or the 15th day of the fourth month after the end of the corporation’s tax year.

Form 1120S (U.S. Income Tax Return for an S Corporation) for S-Corps
Due Date: March 15 (for calendar year filers) or the 15th day of the third month after the end of the corporation’s tax year.
Schedule K-1: Due to shareholders on the same date as Form 1120S.

Form 940 (Employer’s Annual Federal Unemployment (FUTA) Tax Return)
Due Date: January 31.
Reports annual FUTA tax.

Form 1099-NEC (Nonemployee Compensation)
Due Date: January 31.
Required if the company pays $600 or more to independent contractors.

Form W-2 (Wage and Tax Statement)
Due Date: January 31 to employees and Social Security Administration.
Reports wages paid to employees and the taxes withheld.

Form 1096 (Annual Summary and Transmittal of U.S. Information Returns)
Due Date: January 31.
Used to transmit paper Forms 1099 to the IRS.

Form 5500 (Annual Return/Report of Employee Benefit Plan)
Due Date: July 31.
Required if the company offers an employee benefit plan, such as a 401(k).

Form 944 (Employer’s Annual Federal Tax Return)
Due Date: January 31.
Required for small employers with an annual liability for social security, Medicare, and withheld federal income taxes of $1,000 or less.

Additional Business Entities

These business entities are not as common for HVAC, plumbing, and other field service businesses.

Limited Liability Company (LLC)

This type can be treated as a disregarded entity, partnership, or corporation for tax purposes. Filing requirements depend on the tax classification (e.g., Form 1065 for partnerships, Form 1120 for corporations).


General Partnerships, Limited Partnerships (LP), Limited Liability Partnerships (LLP)
Main form: Form 1065 (U.S. Return of Partnership Income) and Schedule K-1s for partners.

Non-Profit Organization (501(c)(3) and others)

Main form: Form 990 (Return of Organization Exempt from Income Tax). Other variations: Form 990-EZ or Form 990-N depending on gross receipts.

B-Corporation (Benefit Corporation)

This generally follows the same filing requirements as a C-Corp or S-Corp but with additional reporting related to social and environmental performance.

Professional Corporation (PC) or Professional Association (PA)

Similar filing requirements to C-Corps or S-Corps depending on how they are structured.

Cooperative (Co-op)

Main form: Form 1120-C (U.S. Income Tax Return for Cooperative Associations).

Final Thoughts

Maintaining compliance with federal form filing requirements is critical for all business entities to avoid penalties and ensure smooth operations. It’s important for these businesses to stay organized and keep track of all due dates for monthly, quarterly, and annual filings.

Consulting with a tax professional can help ensure all forms are filed accurately and on time. By understanding and meeting these obligations, business owners and managers can focus on growing their businesses.