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.

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File Form 1120-S Online for Just $179.99

One flat fee. No hidden charges. Your complete 1120-S e-filing includes K-1 generation for all shareholders.

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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.

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

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

Before you file, make sure your business qualifies:

Your business is a domestic corporation or an LLC that has filed and received IRS approval for
Form 2553 (Election by a Small Business Corporation).
You have income, gains, losses, deductions, or credits to report from U.S. operations.
Your company has 100 or fewer shareholders.
All shareholders are U.S. persons (individuals, estates, certain trusts, or qualifying exempt organizations).
You issue only one class of stock.

If your business meets these criteria, you are required to file Form 1120-S to report your S Corporation’s income and distribute Schedule K-1s to shareholders for their individual tax filings.

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

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.

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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.

Key Schedules Included with IRS Form 1120-S

When filing your S Corporation tax return, several crucial schedules must accompany Form 1120-S to provide a comprehensive financial and tax overview to the IRS:

Schedule K: This schedule summarizes each shareholder’s share of the corporation’s income, deductions, credits, and other tax-related items for the year.
Schedule K-1: Provided individually to each shareholder, Schedule K-1 details their specific portion of the S Corporation’s income or loss to be reported on their personal tax returns.
Schedule L: Presents the corporation’s balance sheet, showing assets, liabilities, and equity at the start and end of the tax year.
Schedule M-1: Reconciles the difference between the corporation’s book income (financial accounting) and taxable income on the return.
Schedule M-2: Tracks changes in the corporation’s retained earnings and accumulated adjustments during the year.

Completing these schedules accurately is essential to comply with IRS regulations and helps prevent errors or delays in processing your tax return.

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Filing Form 1120-S Made Simple for Small Corporations & First-Time Filers

Starting an S Corporation comes with big responsibilities-and filing your first Form 1120-S doesn’t have to be overwhelming. At TaxZerone, we simplify the process so you can focus on running your business, not navigating IRS complexities.

Why This Matters for Small Corporations

Straightforward Pricing: A single flat fee with no surprise charges-perfect for businesses managing tight budgets.
Step-by-Step Guidance: Our platform is designed for filers with little to no prior experience, breaking down IRS requirements into easy steps.
Automatic K-1 Generation: Instantly generate and distribute Schedule K-1s for all shareholders without extra work.
Error-Free Filing: Built-in validation checks catch common mistakes that could delay your return or trigger IRS notices.

First-Time Filers Get Extra Peace of Mind

Clear Explanations at Every Step: We keep things easy to understand by avoiding complex tax terminology.
Free Resources & FAQs: Access practical guides tailored for new S Corporation owners.
Dedicated Support Team: Whether it’s your first filing or you just need reassurance, our experts are ready to help.

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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
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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.

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.

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.

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	✅ 100% trusted by the IRS	✅ Available
Built-in Error Validation	✅ Automatic error check before submission	⚠️Limited or manual checks
K-1 Generation & Delivery	✅ Instant K-1 creation + postal & digital delivery options	✅ Basic K-1 generation only
Transparent Pricing	✅ Flat fee + clear add-ons (no surprises)	❌ Hidden charges & upsells
Support Team Access	✅ Expert help via chat, email, & phone	Limited or delayed support

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Ready to E-file IRS Form 1120-S?

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

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Frequently Asked Questions

1. 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.

2. 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.

3. 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.

4. 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.

5. Can I tell if I am an S Corp or C Corp?

Yes. Review your IRS filings: if you filed and were approved using Form 2553, your business is an S corp. If not, or if you receive a regular corporate tax return notice, you are a C corp.

Free Resources Section

Add-ons:

IRS Form 1120-S Instructions (Download)
IRS Form 2553 Download

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