To correct a South Carolina individual income tax return you already filed, submit an amended return to the South Carolina Department of Revenue (SCDOR). You can either file the SC1040X or send a corrected SC1040 with the “Amended Return” box checked and Schedule AMD attached. To claim a refund on a South Carolina amended tax return, you generally have three years from the date you filed the original return or two years from the date you paid the tax, whichever is later.1South Carolina Legislature. South Carolina Code 12-54-85 – Time Limitation for Assessment of Taxes, Claim for Refund
When You Need to Amend
The usual trigger is discovering that the numbers on your original return were wrong. A late-arriving 1099, a corrected W-2, unreported dividends, a missed credit, or a credit you claimed but weren’t entitled to all call for an amendment. So do changes in filing status (say, from single to married filing jointly), misapplied deductions, and adjustments to items like the South Carolina Two-Wage Earner Credit or the Child and Dependent Care Credit.
You also have to amend when the IRS changes your federal return, whether through an audit or because you filed a federal 1040-X. South Carolina requires the corresponding state amendment within 180 days of the federal change, and you’ll need to include a copy of the IRS’s final determination.
Deadline to File
If you filed your original return on time (by the due date or an extended due date), you can file a claim for refund within the later of three years from the date you filed or two years from the date you paid the tax. If you filed after the original and extended due dates, the window becomes the later of three years from the original due date or two years from payment.
Amendments that increase your tax rather than produce a refund don’t have a formal filing deadline, but interest and penalties keep running from the original due date. Filing sooner keeps those charges smaller.
How to File
The SCDOR recommends filing electronically. Its own guidance calls e-filing “the fastest, safest, easiest way” to submit an amendment.2South Carolina Department of Revenue. Found an Issue After You’ve Filed Your Return? Here’s How to Fix It When you e-file, the Schedule AMD (which explains your changes and lists supporting documents) is built into the process.
On paper, you have two options. Complete the SC1040X, which is a standalone amended return with its own column layout and explanation section. Or file a corrected SC1040, check the “Amended Return” box on the front page, and attach Schedule AMD detailing each change. Either way, include your supporting documents.
Paper amended returns go to one of two SCDOR addresses in Columbia, depending on the outcome of the return:
- Refund or zero tax due: SC1040 Processing Center, PO Box 101100, Columbia, SC 29211-0100
- Balance due: Taxable Processing Center, PO Box 101105, Columbia, SC 29211-0105
These are the same addresses used for original SC1040 returns.3South Carolina Department of Revenue. 2025 SC1040 Individual Income Tax Form and Instructions Sending your return to the wrong box can add weeks to processing.
Filling Out the SC1040X
The heart of the SC1040X is a three-column layout in Part II that shows what changed and by how much.
- Column A: the figures exactly as they appeared on your original return (or the most recently adjusted version).
- Column B: the net increase or decrease for each line you’re changing. Show decreases in parentheses.
- Column C: Column A plus or minus Column B. For any line that didn’t change, carry the Column A figure straight across.
The top of the form asks for the usual identifying information: your name, address, Social Security Numbers for you and your spouse if applicable, the tax year you’re amending, and your filing status. The status should reflect what’s correct, not necessarily what you originally reported.
Part V is where you explain the changes, and it carries more weight than people expect. Tie every change to a specific line. “Correcting income” won’t cut it. Something closer to “Line 1 increased by $3,200 to include 1099-NEC from XYZ Company received after filing” gives the reviewer what they need to approve the change without asking for more. The instructions themselves warn that missing explanations or documents will slow processing.
What to Attach
What you send with the return depends on what you changed, and missing paperwork is one of the most common reasons an amendment stalls. Pull together at least the following where they apply:
- A copy of your federal 1040-X, if you also amended federally.
- The federal audit report or adjustment notice, if the amendment stems from an IRS change.
- Corrected W-2s or 1099s whenever state withholding is changing.
- A completed SC1040TC and the matching TC- schedule for nonrefundable credits; refundable credits need their own South Carolina form.4South Carolina Department of Revenue. Tax Credits
- The other state’s return plus your federal return, if you’re claiming credit for taxes paid to another state.5South Carolina Department of Revenue. 2024 Tax Credits – SC1040TC
- A separate UT-3 for Use Tax corrections.
- A corrected SC4972 for lump-sum distribution tax changes, or a corrected I-335 for changes to the active trade or business tax.
The rule of thumb: every number you change should have a document behind it.
After You File
The SCDOR says original returns take up to eight weeks to process, and amended returns generally take at least that long, sometimes longer during the February-through-April peak. The department typically does not send a confirmation of receipt. Your first sign that it’s been processed is usually a refund or a bill.
If you e-filed, you can track the status through your MyDORWAY account. Paper filers mostly need to wait; calling before the eight-week mark rarely produces useful information.
Refunds from an amended return come by paper check or direct deposit once the SCDOR verifies the corrected figures. Overpayments earn interest at the same rate the state charges on underpayments, so a slow refund arrives with a modest interest payment attached.
Interest and Penalties on a Balance Due
When your amendment shows more tax owed, interest and penalties run from the original due date of the return, not from the date you file the amendment. A correction to a 2024 return filed in 2026 has been accumulating charges since April 2025.
South Carolina’s underpayment interest rate tracks the federal rate and can change quarterly. For January 2025 through March 2026 it is 7%, compounded daily.6South Carolina Department of Revenue. SC Information Letter 25-22 The late-payment penalty is 0.5% per month on the unpaid tax, capped at 25%.7South Carolina Legislature. South Carolina Code Title 12 Chapter 54 – Uniform Method of Collection and Enforcement of Taxes Hitting that cap takes over four years, so the near-term problem is the penalty and daily-compounding interest running together.
To pay, the SCDOR recommends MyDORWAY, its free online portal, which accepts Visa, Mastercard, American Express, and Discover, as well as direct debit from a checking or savings account.8South Carolina Department of Revenue. IIT File and Pay Options If you mail a paper check with the return, write your Social Security Number and the tax year on the check.
Asking for a Penalty Waiver
South Carolina law lets the SCDOR waive, reduce, or dismiss penalties when the taxpayer can show reasonable cause. The standard is whether you exercised ordinary business care and prudence but still couldn’t meet the filing or payment requirement, and the burden is on you.
Serious illness, natural disasters, inability to obtain necessary records, and the death of an immediate family member generally support a waiver. A partial waiver is possible without full reasonable cause when mitigating factors weigh in your favor; the department considers your filing and payment history, the complexity of the issue, and the size and frequency of the error. Not knowing about a requirement, making an honest mistake, or being short on funds usually won’t qualify on its own, though other circumstances can shift the analysis.
If you have grounds, submit a written explanation with your amended return or contact the SCDOR through MyDORWAY.9South Carolina Department of Revenue. MyDORWAY Interest is a separate matter and cannot be waived. It accrues regardless of the reason for the underpayment.