South Carolina state income tax — ITIN filer guide

South Carolina uses a graduated income tax from 1.99% to 5.21% (tax year 2026), administered by the South Carolina Department of Revenue. This guide covers who must file, how filing with an ITIN works, whether the state EITC applies to you, and when refunds arrive.

GRADUATED: 1.99% – 5.21% · 2 brackets

  • State return form: Form SC1040
  • Deadline (tax year 2026): April 15, 2027 (TY2026 returns due April 15, 2027 per SCDOR; e-file + e-pay by May 1 avoids penalties and interest)
  • Who must file: Pre-2026 rule: generally must file if required to file a federal return with SC income (SC started from federal taxable income). H.4216 restructures the calculation for TY2026 — SCDOR has not yet published new TY2026 threshold dollars.
  • State sales tax: 6%
  • Special regime: H.4216 decouples SC from federal standard/itemized deductions: federal AGI is now the starting point, with a new SC Income Adjusted Deduction (SCIAD) of $15,000 single / $22,500 HoH / $30,000 MFJ (income-phased). SCDOR waives penalties/interest if you file AND pay electronically by May 1.
  • Scheduled change: H.4216 (Act 110, signed March 30, 2026) rewrote the income tax effective TY2026: 1.99% on income under $30,000, 5.21% above (computed as 5.21% minus $966). From TY2027, automatic trigger cuts (max $200M/yr revenue impact) phase the top rate down toward 1.99% and eventually toward elimination when revenue grows 5%+.

South Carolina refund timing

  • E-filed returns: Most error-free returns processed in up to 8 weeks from February 2 or the filing date, whichever is later
  • Paper returns: Considerably longer than 8 weeks — mail delivery, sorting, and manual data entry are added before the same processing stages begin
  • Check your South Carolina refund status

State tax agency

  • South Carolina Department of Revenue — dor.sc.gov
  • Phone: 1-844-898-8542
  • Free filing option: No state-run portal — free filing through SCDOR-listed Free File vendor offers (dor.sc.gov/iit) or VITA; MyDORWAY does not file original individual returns

Facts verified 2026-06-11 against official state sources (primary source). Figures refresh with every dataset review.

Filing with an ITIN

Your ITIN is fully accepted on the South Carolina state return — states accept the IRS-issued taxpayer number, the same one you use federally. The flow is always the same:

  1. Complete your federal return first (Form 1040 + ITIN)
  2. Transfer your federal figures to Form SC1040
  3. Apply state-specific deductions and credits
  4. E-file — No state-run portal — free filing through SCDOR-listed Free File vendor offers (dor.sc.gov/iit) or VITA; MyDORWAY does not file original individual returns
  5. Or visit a VITA site for free in-person preparation

South Carolina state EITC — do ITIN filers qualify?

The federal EITC requires valid SSNs for you, your spouse, and qualifying children — ITIN filers can never claim it. What varies is the STATE credit:

South Carolina Earned Income Tax Credit — capped at $200 from TY2026 (was 125% of the federal EITC, nonrefundable, through TY2025) of the federal EITC

✗ SSN required (not available to ITIN filers)

SC's EITC requires eligibility for the federal EITC (SSN required), so ITIN filers cannot claim it. H.4216 limits the credit to $200 beginning TY2026; SCDOR's summary does not restate refundability, but the credit has always been nonrefundable.

See how all 52 jurisdictions compare on the state tax hub and which tax credits ITIN filers can claim.

Last verified: 2026-06-11. Primary source: South Carolina Department of Revenue.

General procedural information for educational purposes. Not legal or tax advice. State tax rates change frequently — verify current figures with the state agency before filing. For case-specific guidance, consult a tax professional, enrolled agent, or CPA.