South Carolina C Corporation Tax Deadlines 2026
Complete guide to C Corporation filing dates, extensions, estimated payment schedules, and required forms in South Carolina for the 2026 tax year. South Carolina imposes a state income tax, so C Corporation entities must file both federal and state returns.
South Carolina C Corporation filing deadline
Calendar-year due date follows federal timing for corporations.
Due: Apr 15, 2026
Extension: Oct 15, 2026
Form: State corporate income tax return
Estimated payments
Quarterly estimated payment dates: Apr 15, 2026, Jun 15, 2026, Sep 15, 2026, Dec 15, 2026.
Due: Apr 15, 2026
South Carolina C Corporation Tax Calendar at a Glance
| Event | Date |
|---|---|
| Filing deadline | Apr 15, 2026 |
| Extension deadline | Oct 15, 2026 |
| Q1 estimated payment | Apr 15, 2026 |
| Q2 estimated payment | Jun 15, 2026 |
| Q3 estimated payment | Sep 15, 2026 |
| Q4 estimated payment | Dec 15, 2026 |
FAQ
When is the C Corporation tax filing deadline in South Carolina for 2026?
The South Carolina C Corporation tax return is due Apr 15, 2026 for the 2026 tax year. An extension is available until Oct 15, 2026.
Does South Carolina require C Corporation estimated tax payments?
Yes, South Carolina requires estimated tax payments for C Corporation entities. The quarterly due dates are: Apr 15, 2026, Jun 15, 2026, Sep 15, 2026, Dec 15, 2026. Penalties may apply if you underpay or miss a deadline.
What form do I file for a C Corporation in South Carolina?
C Corporation entities in South Carolina file using Form State corporate income tax return. You can download the form from South Carolina Department of Revenue at https://dor.sc.gov.
Can I get an extension for my South Carolina C Corporation tax return?
Yes. South Carolina allows an extension for C Corporation returns until Oct 15, 2026. Note that an extension gives you more time to file, not more time to pay — any tax owed is still due by the original deadline of Apr 15, 2026.
What are the penalties for filing late in South Carolina?
South Carolina typically charges a failure-to-file penalty (usually 5% of unpaid tax per month, up to 25%) and a failure-to-pay penalty (usually 0.5-1% per month). Interest also accrues on unpaid balances. Filing for an extension by the original deadline avoids the failure-to-file penalty but not the failure-to-pay penalty.
Where can I file South Carolina C Corporation taxes?
File through South Carolina Department of Revenue. Visit https://dor.sc.gov for e-filing options, downloadable forms, and payment portals.
South Carolina Estimated Tax Payments
View the full quarterly estimated payment schedule for South Carolina, including all entity types and payment methods.
View South Carolina estimated payments →