How to pay South Carolina estimated taxes.

South Carolina collects its own estimated tax through the South Carolina Department of Revenue, separate from the IRS. Here’s who needs to pay, when, and how to pay online.

Do you need to pay?

You must make estimated payments if you expect to owe $100 or more in South Carolina income tax when you file your SC1040, after withholding and credits.

A penalty may apply if you do not pay at least 90% of the total tax due. You can generally avoid it by paying, on time, 100% of the tax shown on your prior-year SC1040 (which must cover a full 12 months). If your prior-year adjusted gross income was more than $150,000, the prior-year rule rises to 110%.

If you underpay: Interest on underpayments for 2026 is 7% from January 1 to March 31, 6% from April 1 to June 30, and 7% from July 1 to December 31 (simple interest for estimated tax underpayments). SCDOR sets the rate periodically by Information Letter.

For how to pick a safe amount, see how much to pay in estimated taxes.

Deadlines

Four equal installments due April 15, June 15, and September 15, 2026, and January 15, 2027. This matches the federal schedule. You can skip the January payment if you file your SC1040 by February 1, 2027 and pay the full balance.

Payment	Due
1st	April 15
2nd	June 15
3rd	September 15
4th	January 15 of the next year

A date on a weekend or holiday moves to the next business day. Pay at least two business days early.

Paying South Carolina, step by step

What you need

Nothing to set up. MyDORWAY takes payments without an account.
Your Social Security number and a copy of last year's South Carolina return.
Your bank routing and account numbers.

Start at MyDORWAY, South Carolina's official payment site.

Go to dor.sc.gov/pay. No account is required.
Select Individual Income Tax Payment.
Enter your SSN, ITIN, or FEIN and legal name, and select Individual Income Tax.
Select Estimated Payment.
Enter the required information, select a payment method, and complete the steps for that method.
Do not mail a paper SC1040ES if you pay online.

Other ways to pay: Mail a check payable to SCDOR with the SC1040ES voucher to SCDOR, IIT Voucher, PO Box 100123, Columbia, SC 29202; put your name, SSN, and 2026 SC1040ES in the memo. SCDOR says MyDORWAY ACH debit and card payments have no convenience fees. A MyDORWAY account lets you schedule payments.

South Carolina will not fill these payments in for you. Your preparer has to enter each estimated payment on your South Carolina return. Keep your own record of the date, amount, and confirmation number.

Extension payments

You get six more months to file. Paying through MyDORWAY by April 15 automatically submits your extension request, so no SC4868 is needed when you pay online. If you owe nothing and have a federal extension, SCDOR accepts the federal extension. The extension does not extend the time to pay.

Make this year's first estimated payment as a separate transaction, marked as an estimate for the current year.

Good to know

Act 110 changes South Carolina income tax starting with tax year 2026: two brackets, taxable income starting from federal AGI, and a new South Carolina Income Adjusted Deduction. The SC1040ES worksheet (Rev. 10/13/25) predates the law, so SCDOR tells estimated payers to read Information Letter #26-20.
If you owe $15,000 or more in connection with any SCDOR return, you must file and pay electronically.
SCDOR does not mail a statement of the estimated tax you paid, so keep your own record.
Individuals whose prior-year tax liability was $0 for a full 12 months are exempt from estimated payments.
Paying other states? See the payment links for every state's official site, and the federal walkthrough.

Official sources

Checked October 2026 against the South Carolina Department of Revenue's own publications.

This guide is for general education and reflects rules as of October 2026. Tax law and agency websites change, and your situation may have details that change the answer. Please talk with your tax professional before acting on it.