File IRS Form 1120-S Online for the 2024 Tax Year

E-file your S corporation’s income tax return with ease. TaxZerone offers a secure, accurate, and IRS-authorized way to file Form 1120-S online - whether you're filing for a single S corp or managing multiple entities.

File Form 1120-S

What You’ll Need to File 1120-S

Corporation Details: Name, EIN, business address, incorporation date
Income and Expenses: Revenue, cost of goods sold, deductions, and credits
Shareholder Information: Name, TIN, percentage ownership, and distributions
K-1 Allocations: Profit/loss distributions to each shareholder
Balance Sheet Details: Assets, liabilities, and retained earnings

Filing again next year? TaxZerone saves your past filings so you can reuse details and file faster.

Eligibility Checklist: Is Form 1120-S Right for Your Business?

Before you file, make sure your business qualifies:

Your business is a domestic corporation.
You've filed Form 2553 and received S corporation approval.
You have no more than 100 shareholders.
All shareholders are U.S. persons.
You issue only one class of stock.

Still Unsure?

Eligibility Checklist: Is Form 1120-S Right for Your Business?

What is IRS Form 1120-S?

IRS Form 1120-S is the annual income tax return filed by S corporations. It reports your company’s income, gains, losses, deductions, and credits - and it’s also used to generate Schedule K-1 for shareholders to report on their personal returns.

Form 1120-S is crucial for maintaining S corporation compliance. Late or incorrect filings can result in penalties or loss of S Corp status.

Who Must File Form 1120-S?

You must file Form 1120-S if your business:

Is classified as an S Corporation
Has an approved Form 2553 (S Corp Election)
Operates as an LLC electing to be taxed as an S Corp / Is an LLC that has filed Form 2553 and is now being taxed as an S Corporation
Has income/loss to report from U.S. operations

How to E-file Form 1120-S with TaxZerone

Filing your Form 1120-S is quick and easy - just follow these steps:

Enter Company Details
Choose Form 1120-S after login and enter corporation and shareholder details via our intuitive interface.
Add Income, Expenses & K-1 Data
Input your business income, deductions, and automatically generate K-1s for shareholders.
Validate & E-file
Our built-in validation checks help ensure your return meets IRS standards before submission.
Distribute K-1s to Shareholders.
After filing, easily send K-1s digitally via ZeroneVault or by mail.

Start Filing 1120-S Now

Why Choose TaxZerone for Form 1120-S E-filing?

IRS-Authorized Provider

Submit your corporate tax return with full confidence on a trusted, IRS-approved platform.

Guided Filing

Even if it’s your first time filing 1120-S, our system guides you through every section.

K-1 Auto-Generation

Simplify shareholder reporting with automatic Schedule K-1 generation and delivery.

Quick Repeat Filing

Returning users can copy prior-year data for faster, easier submissions.

Advanced Error Checks

We scan for missing TINs, calculation errors, and common mistakes-minimizing IRS rejections.

Transparent Pricing

No hidden charges. Pricing that scales with your needs.

Pre-Filing Document Checklist

Be prepared! Here’s what you’ll need to gather before starting:

Corporation name, EIN, address, and incorporation date
Income & expense summaries
List of shareholders and their SSNs/TINs
K-1 allocation percentages
Ending balance sheet figures

Special Pricing for CPAs & Tax Professionals

Got more than one 1120-S to file? Let’s talk savings. We offer exclusive bulk discounts, flexible pricing, and white-glove support for tax professionals and CPAs handling multiple businesses.

Bigger filings = Bigger discounts
Save time with reusable business profiles

📞 Contact Us Now to unlock your custom CPA pricing and make this tax season your easiest yet.

Form 1120-S Filing Deadlines – 2024 Tax Year

These deadlines apply if your S corporation uses a calendar year (Jan 1 – Dec 31).

Filing Type	Deadline
File with IRS (E-file)	March 15, 2025
Shareholder K-1 distribution	March 15, 2025
With Extension ( Form 7004)	September 15, 2025

Note: Deadlines shift to the next business day if they fall on a weekend/holiday.

For Fiscal-Year S Corporations

If your S corp uses a fiscal year (any year ending on a month other than December), the due date is:

The 15th day of the 3rd month after your fiscal year ends.

Example:

If your fiscal year ends June 30, 2025, your 1120-S is due September 15, 2025.
If your fiscal year ends September 30, 2025, your 1120-S is due December 15, 2025.

Need more time to file Form 1120-S?

You can request an extension by filing IRS Form 7004 before the due date.

Penalties for Late or Inaccurate Filing

Avoid costly penalties by filing on time:

Late filing: $245 per shareholder for each month late (max 12 months). If you owe tax, add 5% of the unpaid amount each month (max 25%). If your 2025 return is over 60 days late, you’ll pay at least the smaller of your tax due or $510. IRS 1120-S/PDF
Missing/incorrect K-1s: $330 per K-1 (rises for intentional disregard).

If you’re unsure, contact a CPA or our support - we’ll help you avoid errors and penalties.

E-filing Pricing for Form 1120-S

Flat Rate: $179.99 per
S Corporation filing

No hidden fees. One straightforward price covers your complete 1120-S
e-filing experience, including K-1 generation for all shareholders.

Add-on services:

Postal K-1 Delivery: $1.75 per recipient
ZeroneVault Digital Delivery: $0.50 per recipient

Start Filing Now

Common Use Cases

Annual return for single-member S Corp
K-1 generation for multiple shareholders
Filing with state-level add-ons
Converting from LLC to S Corp and filing for the first time
Preparing accurate 1120-S filings for clients with multiple S corporations

Not sure if you need to file Form 1120-S? Our support team can help you determine your requirements.

Common Mistakes to Avoid

(Pro Tips from a Tax Expert)

Make sure your shareholder compensation is “reasonable.” The IRS often audits S Corps that report high distributions but low salaries.
If your S Corp had no activity this year, you still must file 1120-S (just mark it as a final or zero-activity return).
Double-check TINs to avoid rejection
Don’t miss the K-1 delivery deadline
Match total distributions with retained earnings
Use correct codes on Schedule K

Tips: TaxZerone flags common errors before you submit!

Competitor Comparison: Why TaxZerone Wins

Feature	TaxZerone	Other E-file Platforms
IRS-Authorized	✅	✅
Built-in Error Validation	✅	⚠️
K-1 Generation & Delivery	✅	✅
Transparent Pricing	✅	❌
Support Team Access	✅	Limited

File Form 1120-S Now with TaxZerone

Ready to E-file IRS Form 1120-S?

Avoid penalties, save time, and stay compliant - file securely with TaxZerone in minutes.

Start Filing Form 1120-S Now

Frequently Asked Questions

1. What is IRS Form 1120-S?

Form 1120‑S is the U.S. federal tax return filed by S corporations. It reports income, deductions, credits, and allocates shareholder-specific items via Schedule K‑1, allowing income to pass through to owners’ personal tax returns rather than being taxed at the corporate level.

2. What is the difference between IRS Form 1120 and 1120-S?

Form 1120 is for C corporations, which are taxed at the corporate level. Form 1120‑S is for S corporations, where profits and losses pass through to shareholders to avoid double taxation. Foreign or domestic corporations with more than 100, or non-U.S., shareholders generally use 1120.

3. What tax forms do I file as an S Corp?

As an S corporation, you must file Form 1120‑S. You also issue Schedule K‑1 to each shareholder to report their share of income, deductions, or credits.

4. Is my LLC automatically a 1120 or 1120-S?

No. By default, an LLC is taxed as a sole proprietorship (single member) or partnership (multi-member). To be taxed as an S Corp, you must file Form 2553. Only then do you fileForm 1120‑S, not 1120.

5. How do I tell if a company is an S-Corp or C Corp?

Check if the IRS has accepted Form 2553 for the entity. If yes, it’s an S corporation and files Form 1120‑S. Otherwise, it’s treated as a C corporation and files Form 1120.

Free Resources Section

Add-ons:

IRS Form 1120-S Instructions ( PDF)
IRS Form 2553 Download
"S Corp Tax Checklist" (as a downloadable PDF or gated resource)

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