Business Tax Deadlines

State filing information

South Carolina

Business tax filing in South Carolina: state returns, sales tax, other business taxes, and the federal dates that apply everywhere.

checked 2026-09-01Verified against South Carolina Department of Revenue (SCDOR). 13 sources.

Corporate income tax return

April 15
Corporate income tax of 5% on SC taxable income

Partnership / S corporation returns

March 15
Partnerships March 15; Same for S corporations

Sales tax return

20th of the following month
sales and use tax · Monthly by default; a taxpayer must request SCDOR approval (MyDORWAY web message or email to SalesTax@dor.sc.gov) to file quarterly or annually

Other business taxes

3 taxes
Corporate license fee (annual); Initial corporate license fee (CL-1)

South Carolina Department of Revenue

Other business taxes

TaxWho owes itDue
Corporate license fee (annual)C corporations and S corporations doing business in SC: 0.1% of capital stock and paid-in or capital surplus plus $15 (i.e., $15 + $1 per $1,000), minimum $25Paid with the corporate return: 15th day of the 4th month (SC1120, April 15 calendar year) or 15th day of...
Initial corporate license fee (CL-1)New corporations: file the Initial Annual Report of Corporations (CL-1) and pay a one-time $25 initial license fee to SCDOR within 60 days of initially doing business...Within 60 days of commencing business in SC (one-time)
Active trade or business income entity-level tax (elective, 3%)Qualifying partnerships and S corporations that elect entity-level taxation on Form I-435 (annual election, tax years 2021+)With SC1065 / SC1120S, 15th day of the 3rd month (March 15 calendar year)

Rules in full

Corporate income tax

Corporate income tax of 5% on SC taxable income. All corporate taxable entities other than S corporations and tax-exempt organizations file annually on or before the 15th day of the 4th month after the close of the taxable year; return and payment due together.

Extension. File SC1120-T (Application for Automatic Extension of Time to File a Corporate Tax Return) with payment of any income tax and license fee by the...

Partnerships and S corporations

S corporations owe the annual corporate license fee (0.1% of capital stock and paid-in surplus plus $15, minimum $25) filed with SC1120S; LLCs not taxed as corporations and partnerships do not owe the license fee or annual report. Nonresident withholding: 5% of nonresident shareholders'/partners' SC taxable income (SC1120S-WH / with SC1065), due 15th day of the 3rd month, waived for owners providing an I-309 affidavit or included in a composite return. PTE election: beginning tax year 2021 a qualifying partnership or S corporation may elect annually (by the return due date including extensions) to have its active trade or business income taxed at the entity level at a flat 3%, computed on Form I-435 attached to SC1065/SC1120S; income taxed at entity level is not subject to nonresident withholding.

Sales and use tax

Due date. Returns due the 20th of the month following the reporting period (e.g., January period due February 20).

Filing frequency. Monthly by default; a taxpayer must request SCDOR approval (MyDORWAY web message or email to SalesTax@dor.sc.gov) to file quarterly or annually. Taxpayers with SC tax liability of $15,000 or more per filing period must file and pay electronically.

Annual report

Due Bundled with the corporate income tax return: Schedule D (annual report) is... (South Carolina Department of Revenue...)

Notes

SC is unusual in that the corporate annual report is a schedule of the SCDOR income tax return rather than a Secretary of State filing. The 2025 corporate instructions update IRC conformity through December 31, 2024; no 2024+ change to due dates or the license fee formula was found.

What we could not confirm. Length of the SC1120-T corporate extension is not stated on the SCDOR pages or SC1120I passages fetched (the partnership page states SC8736 gives up to six months), so the C-corp extension length is left unstated. SCDOR publishes no dollar thresholds for quarterly/annual sales tax filing frequency on the pages fetched (approval is by request), so thresholds is null; no sales tax prepayment/accelerated schedule was found, set to null rather than asserting none. Secondary corroboration for the corporate facts is from additional SCDOR pages (Avalara SC guide returned 404, Nolo 402); TaxJar corroborates the sales tax 20th-of-month rule.

Federal dates that apply in South Carolina

  1. SEP15Tue
    Individuals & Sole Proprietors
    Q3 2026 estimated tax payment (Form 1040-ES)
  2. SEP15Tue
    Partnerships
    Form 1065 extended return (Form 7004), tax year 2025
  3. SEP15Tue
    S-Corporations
    Form 1120-S extended return (Form 7004), tax year 2025
  4. SEP15Tue
    C-Corporations
    Q3 2026 corporate estimated tax (Form 1120-W)
  5. OCT15Thu
    Individuals & Sole Proprietors
    Form 1040 extended return (Form 4868), tax year 2025
  6. OCT15Thu
    C-Corporations
    Form 1120 extended return (Form 7004), tax year 2025

All 2026 federal deadlines

Sources

  1. https://dor.sc.gov/ official
  2. https://dor.sc.gov/business-income-taxes/corporate official
  3. https://dor.sc.gov/business-income-taxes/corporate/c-corporation official
  4. https://dor.sc.gov/business-income-taxes/corporate/corporate-faqs official
  5. https://dor.sc.gov/tax/c-corp/filing-req official
  6. https://dor.sc.gov/sites/dor/files/forms/SC1120I.pdf official
  7. https://dor.sc.gov/business-income-taxes/corporate/s-corporation official
  8. https://dor.sc.gov/business-income-taxes/partnership official
  9. https://dor.sc.gov/sites/dor/files/forms/SC1065_2025.pdf official
  10. https://dor.sc.gov/sites/dor/files/forms/I435.pdf official
  11. https://dor.sc.gov/sales-use-tax-index/sales-tax official
  12. https://dor.sc.gov/sales-use-tax-index official
  13. https://www.taxjar.com/sales-tax/south-carolina

Checked 2026-09-01; researcher confidence 0.88. Corrections with a link to the state's own page: contact@businesstaxdeadlines.com.