eftps.gov or irs.gov/payments.
IRS Form 1120-S (U.S. Income Tax Return for an S Corporation) is the annual federal tax return filed by small business corporations that elect pass-through taxation under Subchapter S of the Internal Revenue Code. While S corporations generally pass net profits, losses, deductions, and credits to shareholders via Schedule K-1 (exempting the entity from federal income tax), an S corporation may still owe entity-level taxes.
Entity-level corporate taxes can include Built-in Gains Tax (Section 1374), Excess Net Passive Income Tax (Section 1375), and Investment Credit Recapture. This comprehensive guide details Form 1120-S annual filing deadlines, how to remit corporate tax balances, how to request an automatic 6-month extension with Form 7004, and how to use EFTPS for corporate tax compliance.
Form 1120-S Deadlines & Tax Specifications
Key corporate filing schedules for S Corporation officers:
| Filing Requirement | Statutory Deadline | Compliance Details |
|---|---|---|
| Form 1120-S Annual Return | March 15 (or 15th day of 3rd month) | Mandatory electronic or paper filing including Schedule K-1 for all shareholders |
| Automatic 6-Month Extension | March 15 (Extends to September 15) | Filed via Form 7004; extends filing deadline but does not extend tax payment due date |
| Late Filing Penalty (IRC 6699) | ~$235 / shareholder / month | Assessed monthly (up to 12 months) even if the S Corp owes $0 in entity tax |
| Entity-Level Taxes | 21% Corporate Rate (Flat) | Applies to built-in gains and excess passive investment income |
How to Pay Form 1120-S Corporate Taxes Online (Step-by-Step)
Method 1: Using the Electronic Federal Tax Payment System (EFTPS)
- Visit the official Treasury portal: eftps.gov.
- Log in using your business Employer Identification Number (EIN), PIN, and internet password.
- Select “Make a Payment”.
- Select Tax Form: “1120 – US Corporate Income Tax Return” (or Form 7004 for extensions).
- Select Tax Type: “1120-S Balance Due” or “Estimated Tax”.
- Enter the tax year, payment amount, and authorized bank account routing details.
- Submit at least one business day prior to the due date (before 8:00 PM EST) to ensure timely credit.
Method 2: Electronic Funds Withdrawal (EFW) During E-Filing
When e-filing Form 1120-S or extension Form 7004 through professional tax preparation software (TurboTax Business, Drake, ProConnect, CCH Axcess), you can input your corporate bank routing and account number to authorize a direct withdrawal on the statutory due date.
Method 3: Same-Day Federal Wire Transfer
If you missed the online ACH cutoff window, have your commercial bank originate a Same-Day Federal Tax Wire payment directly to the Federal Reserve Bank following IRS wire instructions at irs.gov/payments/same-day-wire-federal-tax-payments.
Severe Penalties for Late 1120-S Returns
Under IRC Section 6699, the IRS assesses a mandatory late-filing penalty of approx. $235 per shareholder per month (or fraction of a month), up to a maximum of 12 months. For an S Corp with 4 shareholders, filing 5 months late results in a massive $4,700 penalty, even if the corporation had zero taxable income. Always file Form 7004 by March 15 if you need extra time!
IRS Business Support Directory
- IRS Business & Specialty Tax Line: 1-800-829-4933 (Mon–Fri 7:00 AM – 7:00 PM Local Time)
- EFTPS Customer Service: 1-800-555-4477
- Official Website: irs.gov/form1120s
Frequently Asked Questions (FAQ)
Does an S Corporation pay federal income tax directly?
In general, no. S Corporations are pass-through entities. Net corporate income passes directly to shareholders, who report it on their individual tax returns (Form 1040, Schedule E). However, entity-level taxes apply to built-in gains (assets held during C-corp conversion) and excess passive net income.
How do shareholders pay taxes on their S Corporation distributions?
Shareholders receive IRS Schedule K-1 from the S Corp after year-end, which reports their share of ordinary business income, dividends, and capital gains. Shareholders pay income taxes on this income by submitting quarterly Form 1040-ES estimated tax payments.
Related Federal Tax Guides:
Disclaimer: BillPayment.guide is an independent educational portal and is not affiliated with, endorsed by, or operated by the Internal Revenue Service or U.S. Department of the Treasury. For corporate tax strategy, consult a certified CPA or tax attorney.
Anisur Rahman brings over 17 years of experience at the intersection of complex technology and digital strategy to BillPayment.guide. Active in the digital space since 2009, Anisur uses his deep industry insights to break down financial technologies, secure online payment methods, and digital platforms. His actionable guides help readers navigate the fast-paced digital economy and manage their online transactions with confidence.
