SC1120: 'C' Corporation Income Tax Return (Revision 2025-07)

Who files this form

SC1120 is South Carolina’s C Corporation Income Tax Return and includes disregarded LLCs. The supplied form does not state the full rules for determining whether a corporation must file.

All corporations completing the return must complete Schedule D, the annual report. Only multi-state corporations must complete Schedules E, F, G, and H.

When it's due

For tax years 2024, 2025, and 2026, the printed deadline is the 15th day of the fourth month following the close of the taxable year.

Check the extension box on the return if you filed a federal or state extension.

What you'll need

• Complete federal return: Attach a complete copy.
• Withholding forms: Attach 1099s or I-290s if reporting tax withheld on line 14a.
• Credit forms: Attach SC1120TC and tax credit schedules when reporting credits in Schedule C.
• Adjustment schedules: Attach schedules for other additions or other deductions reported in Schedules A and B.
• Declaration penalty form: Attach SC2220 if reporting a declaration penalty on line 17c.
• Annual report information: Have the corporation’s registered office, registered agent, stock, director, officer, and stated capital information ready for Schedule D.
• Consolidated return schedules: Complete and attach Schedule J for each corporation included in the consolidation.
• Disregarded LLC information: Schedule L asks for the name and FEIN or South Carolina file number of each disregarded LLC doing business in South Carolina or registered with the South Carolina Secretary of State.

How to file

File electronically: Use Modernized Electronic Filing (MeF). The form directs filers to dor.sc.gov/biz-services for more information.

Mail a balance-due return to:

SCDOR Corporate Taxable

PO Box 100151

Columbia, SC 29202

Mail a refund or zero-tax return to:

SCDOR Corporate Refund

PO Box 125

Columbia, SC 29214-0032

Pay online: Use MyDORWAY at dor.sc.gov/pay and select Business Income Tax Payment.

Pay by check: Make the check payable to SCDOR. Include your name, FEIN, tax year, and SC1120 in the memo. Do not send cash.

Attach a complete copy of your federal return and complete the officer signature fields.

Common mistakes

• Leaving out the federal return: The form reminds filers to attach a complete copy.
• Sending cash: The form specifically says not to send cash.
• Entering negative stated capital amounts: Schedules D and J say paid-in capital stock, paid-in capital surplus, and total stated capital cannot be negative.
• Using incorrect direct deposit details: Only US accounts are allowed. The routing number must have 9 digits and begin with 01 through 12 or 21 through 32. The account number must have 1 to 17 digits.
• Treating a final return as the only closure step: The form says you must close with both the South Carolina Secretary of State and SCDOR.
• Including the wrong corporations on Schedule M: The form says to include only corporations doing business in South Carolina.

Questions people ask

What income tax rate does SC1120 use?

Line 7 calculates tax by multiplying South Carolina net income subject to tax on line 6 by 5%.

Does this return also calculate a License Fee?

Yes. Part II calculates the License Fee. Line 21 multiplies the amount on line 20 by .001 and adds $15. The fee cannot be less than $25 per taxpayer.

Can I apply an income tax overpayment instead of receiving a refund?

Yes. Line 19 provides options to apply the overpayment to Estimated Tax, apply it to the License Fee, or receive a refund.

Can I receive my refund by direct deposit?

Yes. The form offers direct deposit to a US checking or savings account. Enter the account type, routing number, and bank account number.

Where do I list disregarded LLCs included in the return?

Use Schedule L. List each disregarded LLC doing business in South Carolina or registered with the South Carolina Secretary of State. Add Schedule L forms as needed.

Official sources

• https://dor.sc.gov/sites/dor/files/forms/SC1120.pdf