SC1120U: Public Utility Tax Return (Revision 2023-05)
South Carolina · South Carolina DOR · Used for tax years 2024, 2025, 2026
Form SC1120U is South Carolina's Public Utility Tax Return. It reports income, adjustments, credits, payments, and amounts due or overpaid for Income Tax and the License Fee, and includes a corporate annual report.
Who files this form
SC1120U is South Carolina's Public Utility Tax Return. The form addresses both Public Utility C Corporations and Public Utility S Corporations.
Schedule K states that the License Fee applies to every express, street railway, navigation, waterworks, power, light, gas, telegraph, and telephone company.
All corporations must complete Schedule D, the annual report. Only multi-state corporations must complete Schedules F, G, and H.
When it's due
For tax years 2024, 2025, and 2026, the printed filing deadline is the 15th day of the fourth month following the close of the taxable year.
An extension gives more time to file, not more time to pay. Any tax due must be paid by the due date to avoid late penalties and interest.
What you'll need
- A complete copy of your federal return, which must be attached.
- Your FEIN and corporation details, including mailing address, audit contact, and the corporate information requested in Schedule D.
- Income, payment, property, and receipt records needed to complete the return. Schedule K uses the prior tax year's property value determined by SCDOR and South Carolina receipts.
- Credit and withholding attachments, if applicable: SC1120TC and tax credit schedules for credits, and Forms 1099 or I-290 for tax withheld. Attach SC2220 for the declaration penalty entry.
- Schedules explaining other additions or deductions, if reported in Schedule A and B.
- Consolidated return information, if applicable: attach Schedule J for each corporation included in the consolidation and complete the consolidated return affiliations information in Schedule M.
If claiming the infrastructure credit on line 17, complete Schedule I and attach a schedule identifying the project, the person completing it, its county, the qualifying statutory sections, cash payments with recipients and dates, the infrastructure provided, and its actual or expected completion date. If the infrastructure is not complete when you file, include a waiver of the statute of limitations.
How to file
Complete the applicable schedules, attach a complete federal return, and have an officer sign and date the return.
Mail balance-due returns to:
SCDOR Corporate Taxable
PO Box 100151
Columbia, SC 29202
Mail refund or zero-tax returns to:
SCDOR Corporate Refund
PO Box 125
Columbia, SC 29214-0032
Payment: Pay online through MyDORWAY at dor.sc.gov/pay and select Business Income Tax Payment. If paying by check, make it payable to SCDOR and include your name, FEIN, tax year, and SC1120U in the memo. Do not send cash.
The supplied text describes online payment and extension requests, but does not provide instructions for e-filing the return.
Common mistakes
- Leaving out your FEIN or federal return. The form requires your FEIN and a complete copy of your federal return.
- Treating a filing extension as extra time to pay. There is no extension of time for payment of tax.
- Forgetting the extension checkbox. Mark it if you filed a state or federal extension.
- Sending cash. The form specifically says not to send cash.
- Missing closure requirements on a final return. You must close with both the South Carolina Secretary of State and SCDOR.
- Including corporations not doing business in South Carolina on Schedule M. That schedule says to include only corporations doing business in the state.
Questions people ask
What Income Tax rate does the form use?
Line 7 calculates tax by multiplying South Carolina net income subject to tax on line 6 by 5%.
What is the minimum License Fee?
Schedule K sets a $25 minimum before the Section 12-20-105 credit. The amount after that credit cannot be less than zero.
How do I request a filing extension?
Pay your balance due through MyDORWAY at dor.sc.gov/pay and select Business Income Tax Payment. The payment automatically submits your extension request, with no additional paperwork. To request an extension by mail, use SC1120-T. If no tax is due and you requested a federal extension, South Carolina accepts it if SCDOR receives your return within the IRS-extended time. An extension does not extend the payment deadline.
Which additional instructions should I use?
Public Utility C Corporations should use the SC1120 Instructions. Public Utility S Corporations should use the SC1120S Instructions. Both are available at dor.sc.gov/forms.
Do I need to list disregarded LLCs?
Schedule L asks you to list each disregarded LLC doing business in South Carolina or registered with the South Carolina Secretary of State. Include additional Schedule Ls as needed.