Individual Declaration of Estimated Tax Want more information about Individual Income Taxes? Visit dor.sc.gov/iit Fast. Easy. Secure. Manage your tax accounts online for FREE! Why MyDORWAY? • Make ACH debit or credit card payments with no convenience fees • Option to schedule payments (SC1040ES and SC1040V) • Access and update your account information 24/7 • Automatic calculations reduce errors Ready to sign up for MyDORWAY? Go to dor.sc.gov/MyDORWAY to get started You’ll need: • Your SSN, ITIN, or FEIN • Your last payment amount or copy of your last return How to pay with MyDORWAY Visit dor.sc.gov/pay • Select Individual Income Tax Payment • Enter SSN, ITIN, or FEIN and Legal Name, and select Individual Income Tax • Next, select Estimated Payment • Enter the required information, and select a payment method • Next, complete the required steps for the selected payment method • Do not mail a paper copy of the SC1040ES if you pay online Pay online with MyDORWAY! No account or additional paperwork required! By paying on MyDORWAY you: • receive immediate confirmation for transactions • can make your payment anytime, 24/7 • don’t have to worry about using the correct tax year voucher

cut along dotted line Name and address (include spouse's name if filing jointly) SC1040ES (Rev. 10/13/25) 3080 Payment amount Your SSN Composite Filer . 2026 Spouse's SSN (if filing jointly) 1350 SC DEPARTMENT OF REVENUE INDIVIDUAL DECLARATION OF ESTIMATED TAX Do not send cash. Make your check payable to SCDOR and include your name, SSN, and 2026 SC1040ES in the memo. 30801260 1st Qtr Jan, Feb, Mar Mark quarter with X (required) 3rd Qtr Jul, Aug, Sep 2nd Qtr Apr, May, Jun 4th Qtr Oct, Nov, Dec 00 dor.sc.gov Pay online! It's quick and easy! Use our free online tax portal, MyDORWAY, at dor.sc.gov/pay. STATE OF SOUTH CAROLINA DEPARTMENT OF REVENUE 2026 INDIVIDUAL DECLARATION OF ESTIMATED TAX STATE OF SOUTH CAROLINA DEPARTMENT OF REVENUE SC1040ES (Rev. 10/13/25) 3080 1350 dor.sc.gov INSTRUCTIONS

Pay online using our free tax portal, MyDORWAY, at dor.sc.gov/pay. Select Individual Income Tax Payment to get started. Do not mail a paper copy of the SC1040ES if you pay online.

• If you owe $15,000 or more in connection with any SCDOR return, you must file and pay electronically according to SC Code Section 12-54-250.

• If you're making an Individual Income Tax return payment, use the SC1040V.

• If you file by paper, use only black ink on the SC1040ES form and on your check.

• Enter your Social Security Number (SSN) and your spouse's SSN (if filing jointly).

• Check the Composite Filer box if this payment will be claimed on a SC1040, Individual Income Tax Return, filed for nonresident partners or shareholders of a Partnership or S Corporation.

• Mark the box for the quarter the payment is being made.

• Enter your name and address, including apartment number and ZIP.

• Enter your payment amount in whole dollars without a dollar sign (for example: 154.00).

• Your payment amount should match the amount on line 11 of your 2026 Estimated Tax Worksheet.

• If no payment is due, do not mail the SC1040ES.

• Make your check payable to SCDOR. Include your name, SSN, and 2026 SC1040ES in the memo. Do not send cash.

• Mail your SC1040ES and payment in one envelope.

Mail your SC1040ES and payment to: SCDOR, IIT Voucher, PO Box 100123, Columbia, SC 29202

Name and address (include spouse's name if filing jointly) SC1040ES (Rev. 10/13/25) 3080 Payment amount Your SSN Composite Filer . 2026 Spouse's SSN (if filing jointly) 1350 SC DEPARTMENT OF REVENUE INDIVIDUAL DECLARATION OF ESTIMATED TAX Do not send cash. Make your check payable to SCDOR and include your name, SSN, and 2026 SC1040ES in the memo. 30801260 1st Qtr Jan, Feb, Mar Mark quarter with X (required) 3rd Qtr Jul, Aug, Sep 2nd Qtr Apr, May, Jun 4th Qtr Oct, Nov, Dec 00 dor.sc.gov Pay online! It's quick and easy! Use our free online tax portal, MyDORWAY, at dor.sc.gov/pay. Pay online! It's quick and easy! Use our free online tax portal, MyDORWAY, at dor.sc.gov/pay. cut along dotted line Name and address (include spouse's name if filing jointly) SC1040ES (Rev. 10/13/25) 3080 Payment amount Your SSN Composite Filer . 2026 Spouse's SSN (if filing jointly) 1350 SC DEPARTMENT OF REVENUE INDIVIDUAL DECLARATION OF ESTIMATED TAX Do not send cash. Make your check payable to SCDOR and include your name, SSN, and 2026 SC1040ES in the memo. 30801260 1st Qtr Jan, Feb, Mar Mark quarter with X (required) 3rd Qtr Jul, Aug, Sep 2nd Qtr Apr, May, Jun 4th Qtr Oct, Nov, Dec 00 dor.sc.gov cut along dotted line Name and address (include spouse's name if filing jointly) SC1040ES (Rev. 10/13/25) 3080 Payment amount Your SSN Composite Filer . 2026 Spouse's SSN (if filing jointly) 1350 SC DEPARTMENT OF REVENUE INDIVIDUAL DECLARATION OF ESTIMATED TAX Do not send cash. Make your check payable to SCDOR and include your name, SSN, and 2026 SC1040ES in the memo. 30801260 1st Qtr Jan, Feb, Mar Mark quarter with X (required) 3rd Qtr Jul, Aug, Sep 2nd Qtr Apr, May, Jun 4th Qtr Oct, Nov, Dec 00 dor.sc.gov Pay online! It's quick and easy! Use our free online tax portal, MyDORWAY, at dor.sc.gov/pay.

SC1040ES INSTRUCTIONS 2026

Filing requirements You must file a Declaration of Estimated Tax if you expect to owe an Income Tax liability of $100 or more with the filing of your SC1040, Individual Income Tax Return.

Use the Estimated Tax Worksheet to compute your Estimated Tax:

• If you are a resident of South Carolina, use your 2025 SC1040 as a basis for figuring your Estimated Tax.

• If you are a nonresident of South Carolina, use your 2025 SC1040 and Schedule NR as a basis to calculate the modified South Carolina taxable income to enter on line 3 of the Worksheet.

Exceptions to filing a Declaration of Estimated Tax:

• Farmers and commercial fishermen whose gross income from farming or fishing for 2025 or 2026 is at least two-thirds (66.67%) of their total gross income from all sources. Instead of making four quarterly Estimated Tax payments, farmers and commercial fishermen may choose to pay all of their Estimated Tax by January 15, 2027 or file their 2026 SC1040 and pay the total tax due by March 1, 2027

• Individuals whose prior year tax liability was $0 for a full 12 months

• Nonresidents of South Carolina doing business in this state on a contract basis where the contract is more than $10,000 and tax is withheld at 2% from each contract payment

Declaration adjustment If your Estimated Tax has substantially increased or decreased due to a change in income, dependents, or Income Tax withholding, file the adjusted Declaration by the next payment due date. Use the SC1040ES to make the adjusted payment.

Complete the Adjusted Declaration Schedule, found on page 4 of these instructions, to determine the amount to be paid. Use the corrected amounts of income and deductions from your federal information.

Payment due dates 1. If you file using a calendar year end of December 31, your Estimated Tax payments are due in four equal installments:

• 1st quarter: due April 15, 2026

• 2nd quarter: due June 15, 2026

• 3rd quarter: due September 15, 2026

• 4th quarter: due January 15, 2027

You can choose to pay all of your Estimated Tax on April 15, the due date of the first installment. Instead of making your last payment on January 15, you can choose to file your SC1040 by February 1 and pay the full balance of Income Tax due.

2. If you are not required to file on April 15:

• Your first Estimated Tax payment is due on June 15, 2026 if you meet your Estimated Tax filing requirement after April 1 and before June 1.

• Your first Estimated Tax payment is due on September 15, 2026 if you meet your Estimated Tax filing requirement after June 1 and before September 1.

• Your first Estimated Tax payment is due on January 15, 2027 if you meet your Estimated Tax filing requirement after September 1.

3. If you file on a fiscal tax year, your Estimated Tax payments are due on the 15th day of the fourth, sixth, and ninth months of the fiscal year and the first month of the following fiscal year.

Penalty for failure to file and pay Estimated Tax You may be charged a penalty if:

• you do not pay enough Estimated Tax.

• you do not make your payments by the due date and for the required amount.

• you do not pay at least 90% of the total tax due.

A penalty will not be charged if your underpayment results from personal service income earned in another state and tax was withheld to the other state.

Generally, you can avoid a penalty if you make timely Estimated Tax payments equal to 100% of the tax shown due on your SC1040 for the prior tax year. You must have filed a SC1040 for the prior tax year, and it must have covered a 12-month year.

If the adjusted gross income on your prior year SC1040 was more than $150,000, the 100% rule is adjusted to 110% of last year's tax liability. Calculate adjusted gross income by using federal guidelines and making South Carolina adjustments.

Refer to the SC2210, Underpayment of Estimated Tax By Individuals, Estates, and Trusts, available at dor.sc.gov/forms, for more information on computing the underpayment penalty.

2026 Tax Computation Schedule for South Carolina Residents and Nonresidents 2026 Adjusted Declaration Schedule Record of Estimated Tax Payment The SCDOR does not mail a statement of the amount of Estimated Tax paid during the year. Complete this section for your records. 2026 Estimated Tax Worksheet 1. Enter the federal taxable income from your 2026 federal 1040ES, line 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. $ 2. South Carolina state adjustments (positive or negative) For purposes of the 110% rule, include Active Trade or Business Income . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. $ 3. South Carolina taxable income (add line 1 and line 2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3. $ 4. Tax (calculate the tax on line 3 using the Tax Computation Schedule in these instructions) . . . . . . . . . . . . . . . . . . 4. $ 5. Enter any additional tax (from your SC4972 or I-335) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5. $ 6. Add line 4 and line 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6. $ 7. Nonrefundable credits (Child and Dependent Care Credit, Two Wage Earner Credit, and credits from your SC1040TC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7. $ 8. Subtract line 7 from line 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8. $ 9. State Income Tax withheld and estimated to be withheld during year 2026 Include withholding from wages, pension, and annuities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9. $ 10. Balance of Estimated Tax (subtract line 9 from line 8) If $100 or more, you must make Estimated Tax payments. If less than $100, no payment is required. Round to the nearest dollar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10. $ 11. If the first payment you are required to file is: due April 15, 2026, enter 1/4 due June 15, 2026, enter 1/2 of line 10, minus any 2025 overpayment applied to 2026 Estimated due September 15, 2026, enter 3/4 due January 15, 2027, enter amount Tax. Enter here and as the payment amount on your voucher . . . . . . . 11. $ } 1. Adjusted Estimated Tax (line 11 of Estimated Tax Worksheet). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. 2. Subtract: a. Amount of 2025 overpayment applied to Estimated Tax for 2026 . . . . . . . . . . . . . . . . . . . . . . . . . . 2a. b. Total Estimated Tax payments made. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2b. c. Total (add line 2a and line 2b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2c. 3. Unpaid balance (subtract line 2c from line 1). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3. 4. Amount to be paid (line 3 divided by number of remaining payments) Enter here and as the payment amount on the SC1040ES voucher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4. Overpayment credit on 2025 return Voucher 1 Voucher 2 Voucher 3 Voucher 4 Total Amount Date Tax Computation Schedule Example of computation If the amount on line 3 of worksheet is: At But less South Carolina income subject to tax on line 3 of least than Compute the tax as follows: worksheet is $25,000. The tax is calculated as follows: $0 $3,640 0% times the amount 3,640 18,230 3% times the amount minus $109 $25,000 income from line 3 of worksheet 18,230 or more 6% times the amount minus $656 X .06 percent from tax computation schedule 1,500 (1,500 rounded to the nearest dollar) - 656 amount from tax computation schedule $ 844 tax to be entered on line 4 of worksheet

Social Security Privacy Act Disclosure It is mandatory that you provide your Social Security Number on this tax form if you are an individual taxpayer. 42 U.S.C. 405(c)(2)(C)(i) permits a state to use an individual's Social Security Number as means of identification in administration of any tax. SC Regulation 117-201 mandates that any person required to make a return to the SCDOR must provide identifying numbers, as prescribed, for securing proper identification. Your Social Security Number is used for identification purposes. The Family Privacy Protection Act Under the Family Privacy Protection Act, the collection of personal information from citizens by the SCDOR is limited to the information necessary for the SCDOR to fulfill its statutory duties. In most instances, once this information is collected by the SCDOR, it is protected by law from public disclosure. In those situations where public disclosure is not prohibited, the Family Privacy Protection Act prevents such information from being used by third parties for commercial solicitation purposes.