SC1120S: 'S' Corporation Income Tax Return (Revision 2025-06)

When it's due

The return is due by the 15th day of the third month following the close of the taxable year. The form does not print separate calendar deadlines for individual tax years.

What you'll need

• Complete federal return: Attach a complete copy. SC1120S uses amounts from Schedule K of federal Form 1120S.
• Annual report information: Schedule D asks for incorporation details, registered and principal office information, share information, directors and officers, and stated capital.
• Withholding documents: Attach 1099s or I-290s if claiming tax withheld on line 13a.
• Credit form: Attach SC1120TC when reporting nonrefundable tax credits.
• Other supporting forms, if applicable: Use I-435 for the active trade or business amounts on lines 5 and 6. Attach SC2220 for a declaration penalty on line 16c.
• Supporting schedules and explanations: Attach schedules for other additions and deductions. Explain income listed in Schedule F that is not allocated to South Carolina, and provide an explanation or listing for other property on Schedule N, line 5.
• Direct deposit details, if selected: Have your account type, routing number, and bank account number ready.

How to file

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

File by mail: Use the address that matches your return.

Refund or zero-tax returns:

SCDOR Corporate Refund

PO Box 125

Columbia, SC 29214-0032

Balance-due returns:

SCDOR Corporate Taxable

PO Box 100151

Columbia, SC 29202

Pay electronically: 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 SC1120S in the memo. Do not send cash.

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

Common mistakes

• Claiming withholding twice: Do not claim tax withheld on line 13a if it was claimed on SC1120S-WH.
• Leaving out attachments: The form reminds you to attach a complete federal return and SC1120TC when reporting nonrefundable credits.
• Skipping the annual report: Schedule D must be completed by all corporations.
• Entering negative stated capital: Schedule D says 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 account number must contain 1 to 17 digits. The routing number must contain 9 digits and begin with 01 through 12 or 21 through 32.
• Treating a final return as the only closing step: The form says you must close your account with both the South Carolina Secretary of State and SCDOR.
• Sending cash: The form specifically says not to send cash.

Questions people ask

How is the License Fee calculated?

Multiply the amount on line 19 by .001, then add $15. The fee on line 20 cannot be less than $25. Multi-state corporations use Schedule E to calculate the amount for line 19.

Which corporations complete Schedules E, F, G, and H?

The form says only multi-state corporations must complete these schedules.

Which subsidiaries and LLCs belong on Schedule L?

List each Qualified Subchapter S Subsidiary (QSSS) and each disregarded LLC that does business in South Carolina or is registered with the South Carolina Secretary of State.

What can I do with an income tax overpayment?

Line 18 lets you apply the overpayment to estimated tax, apply it to the License Fee, or request a refund.

What sales ratio do I use if there are no sales anywhere?

For Schedule H-1, enter 100% on line 3 if South Carolina is the principal place of business. Enter 0% if the principal place of business is outside South Carolina.

Official sources

• https://dor.sc.gov/sites/dor/files/forms/SC1120S.pdf