Filing Requirements
& Due Dates

Master the rules for who must file, which forms to use, and when returns are due for individuals, corporations, and partnerships.

CPA Regulation (REG)

What Are Filing Requirements?

Filing requirements are the IRS rules that determine whether a taxpayer must submit a federal income tax return. They depend on factors like filing status, gross income thresholds, age, and dependency status.

Key Terms You Must Know

Gross Income

All income from all sources before exclusions. Includes wages, interest, dividends, and business income.

Filing Status

Determines your tax bracket and standard deduction: Single, MFJ, MFS, HoH, or Qualifying Surviving Spouse.

Due Date

The deadline by which a return must be filed or an extension requested to avoid penalties and interest.

Why Does This Matter?

On the CPA REG exam, you will be tested on your ability to identify who must file, which form to use, and when it is due. Failure to file correctly in practice results in penalties, interest, and potential legal consequences.

1

Failure-to-file penalty: 5% of unpaid tax per month, up to 25%.

2

Failure-to-pay penalty: 0.5% of unpaid tax per month, up to 25%.

3

Interest: Accrues from the original due date on any unpaid balance.

Individual Filing Thresholds

An individual must file if gross income meets or exceeds the standard deduction for their filing status. The thresholds are adjusted annually for inflation.

Filing Status	Under 65	65 or Older
Single	$ \$14{,}600 $	$ \$16{,}550 $
MFJ (both under 65)	$ \$29{,}200 $	$ \$30{,}750+ $
Head of Household	$ \$21{,}900 $	$ \$23{,}850 $
MFS	$ \$5 $ (any income)

Special Rules: Must File Regardless

Certain taxpayers must file regardless of whether their gross income meets the threshold:

1

Self-employment income: Net SE income of $ \$400 $ or more.

2

Church employee income: $ \$108.28 $ or more in wages from a church.

3

Advance Premium Tax Credit: Received APTC through the Health Insurance Marketplace.

4

AMT liability: Owe Alternative Minimum Tax.

5

Household employee taxes: Owe Social Security/Medicare tax on household worker wages.

Core Due Dates by Entity

Mar 15

S Corps (Form 1120-S) & Partnerships (Form 1065)

Calendar-year pass-through entities file by the 15th day of the 3rd month

Apr 15

Individuals (Form 1040) & C Corps (Form 1120)

Calendar-year individuals and C corporations file by the 15th day of the 4th month

May 15

Tax-Exempt Orgs (Form 990)

Calendar-year exempt organizations file by the 15th day of the 5th month

Sep 15

Extended S Corps & Partnerships

6-month automatic extension from March 15

Oct 15

Extended Individuals & C Corps

6-month automatic extension from April 15

The Due Date Formula

Forms by Entity Type

Individual

Form 1040: U.S. Individual Income Tax Return. Due: April 15. Extension: October 15.

C Corporation

Form 1120: U.S. Corporation Income Tax Return. Due: April 15. Extension: October 15.

S Corporation

Form 1120-S: S Corp Income Tax Return. Due: March 15. Extension: September 15.

Partnership

Form 1065: U.S. Return of Partnership Income. Due: March 15. Extension: September 15.

Pass-Through vs. C Corp Dates

The key distinction: pass-through entities (S corps, partnerships) file one month earlier than C corps and individuals. This ensures K-1 information reaches partners/shareholders before their personal returns are due.

Feature	Pass-Through (1065/1120-S)	C Corp / Individual (1120/1040)
Original Due Date	March 15	April 15
Extension Length	6 months	6 months
Extended Due Date	September 15	October 15
Issues K-1s?	Yes	No (C Corp) / N/A (Individual)
Pays Own Tax?	No (flows to owners)	Yes

Extension Rules: Time, Not Payment

1

Individuals: File Form 4868 for an automatic 6-month extension.

2

Corporations: File Form 7004 for an automatic 6-month extension.

3

Partnerships & S Corps: Also file Form 7004 for 6 months.

4

Payment estimate: Must pay estimated tax liability with the extension request to avoid penalties.

How to Determine Filing Requirements

1

Identify the entity type: Individual, C corp, S corp, partnership, or tax-exempt org?

2

Determine filing status (individuals): Single, MFJ, MFS, HoH, or QSS?

3

Compare gross income to threshold: Is income at or above the standard deduction for that status?

4

Check special rules: Self-employment $ \geq \$400 $? AMT? APTC? If yes, must file regardless.

5

Identify the correct form and due date based on entity type and year-end.

6

Check for extensions: Was Form 4868 or 7004 filed? Adjust the due date accordingly.

Example 1: Single Filer

1

Entity type: Individual

2

Filing status: Single, under 65

3

Threshold: $ \$14{,}600 $ for Single under 65

4

Comparison: $ \$18{,}500 \geq \$14{,}600 $ ✓ Must file

5

Form & Due Date: Form 1040, due April 15, 2025

Example 2: Self-Employed Filer

1

Gross income check: $ \$3{,}200 \lt \$14{,}600 $ threshold. Normally: no requirement.

2

Special rule check: Net self-employment income = $ \$3{,}200 \geq \$400 $.

3

Result: Must file regardless of gross income threshold. Owes SE tax.

4

Forms: Form 1040 + Schedule SE + Schedule C. Due: April 15.

Example 3: Partnership Due Date

1

Entity type: Partnership (pass-through).

2

Original due date: 15th day of the 3rd month = March 15.

3

Extension: 6 months from March 15.

4

Extended due date: September 15. Form 1065 must be filed by then.

Common Mistakes

✕ Extension = Extra Time to Pay

An extension only extends the filing deadline. Tax payment is still due on the original date. Interest accrues on unpaid balances.

✕ Same Due Date for All Entities

Pass-through entities (S corps, partnerships) are due March 15, one month before C corps and individuals.

✕ Ignoring the SE Income Rule

Self-employment income of $ \$400+ $ triggers a filing requirement even when gross income is below the standard deduction.

Master Reference Table

Entity	Form	Original Due	Extended Due	Ext. Form
Individual	1040	Apr 15	Oct 15	4868
C Corporation	1120	Apr 15	Oct 15	7004
S Corporation	1120-S	Mar 15	Sep 15	7004
Partnership	1065	Mar 15	Sep 15	7004
Tax-Exempt	990	May 15	Nov 15	8868

Question 1 of 5

A calendar-year partnership wants to file an extension. Which form should it use, and what is the extended due date?

Partnerships file Form 7004 for an extension. The original due date is March 15, so a 6-month extension moves the deadline to September 15. Form 4868 is for individuals only.

Question 2 of 5

A single taxpayer, age 30, earned $ \$12{,}000 $ in wages and no other income. Must this taxpayer file a federal return?

The 2024 filing threshold for Single under 65 is $ \$14{,}600 $. Since $ \$12{,}000 \lt \$14{,}600 $, this taxpayer is not required to file (though they may choose to for a refund).

Question 3 of 5

Why do S corporations and partnerships have an earlier filing deadline than C corporations and individuals?

S corporations and partnerships issue Schedule K-1 forms to their owners. The earlier March 15 deadline ensures owners have the K-1 information they need to complete their own individual returns by April 15.

Question 4 of 5

A taxpayer files Form 4868 for an automatic extension. Which statement is true?

An extension extends the time to file, not the time to pay. The taxpayer must still pay estimated taxes by April 15. Failure to pay by the original due date results in interest and penalties on the unpaid balance.

Question 5 of 5

A single taxpayer, age 25, earned $ \$800 $ from freelance work and had no other income. Which statement is correct?

Even though gross income of $ \$800 $ is well below the $ \$14{,}600 $ standard deduction, the self-employment income rule applies: net SE income of $ \$400 $ or more triggers a mandatory filing requirement.