SC – New Tax Bill Non-Conformity (2025) | 1040.com®

Article: 50666

Important  The information below was based on the state of legislation and the DOR information letter dated January 30, 2026.

March 18, 2026 Update: Additional legislation has been introduced in the South Carolina legislature. This legislation has not been enacted and remains subject to change. We are actively monitoring the situation. If legislation is enacted, we will work with the South Carolina DOR to evaluate and implement any necessary program updates in accordance with applicable guidance.

March 27, 2026 Update: Due to possibility of legislative changes, the SC DOR has decided to automatically extend the tax filing due date for all 2025 South Carolina Individual Income Tax returns to October 15, 2026.

• While you do not need to file an extension to get the extra time to file, you will need to pay any amount due by April 15, 2026 to avoid penalties.
• You can pay online at dor.sc.gov/pay.

Additional information will be provided here as it becomes available.

South Carolina did not conform to certain federal tax law changes under the new tax bill. As a result, specific deductions allowed on the federal return must be added back when calculating South Carolina taxable income.

The following items must be added back on the South Carolina return. The adjustment appears on line 1a (SALT Addback) or 1e (all other addbacks). These items are adjusted automatically by the program, unless otherwise indicated.

• State and Local Tax (SALT) Deduction Addback – The South Carolina addback is the lesser of:
  • Itemized deductions in excess of the federal standard deduction that would have been allowed if the standard deduction had been used;
  • State and local income taxes or general sales taxes reported on federal Schedule A, Line 5a; or
  • The $40,000 federal SALT deduction limit minus deductible property taxes.
• Increased Standard Deduction Amounts – South Carolina does not conform to the increased federal standard deduction amounts. The additional amounts must be added back as follows:
  • $750 – Single and Married Filing Separately
  • $1,125 – Head of Household
  • $1,500 – Married Filing Jointly and Qualifying Surviving Spouse
• Overtime Premium Deduction – The full amount deducted on the federal return must be added back.
• “No Tax on Tips” Deduction – The full amount deducted on the federal return must be added back.
• Enhanced Senior Deduction – Individuals aged 65 or older who claim the $6,000 federal deduction must add this amount back on the South Carolina return.
• “No Tax on Car Loan Interest” Deduction – The full amount deducted on the federal return must be added back.
• Business Asset Deductions – The full amount deducted on the federal return must be added back.
• Research and Experimental Expenditures – The full amount deducted on the federal return must be added back. This adjustment must be made manually, if applicable, by following these steps:
  1. Go to State Taxes.
  2. Click I’d like to see the forms I’ve filled out or search for a form.
  3. Click the South Carolina drop-down.
  4. Select 1040/Sch NR – Income Tax Form – Additions and Subtractions.
  5. Enter a Type and Amount under Other Additions.
  6. Click Save.

More Info

For additional information, refer to the South Carolina DOR Conformity Update.

Note  This new tax bill, was signed into law on July 4, 2025. The One Big Beautiful Bill Act (OBBB or OB3) is now also being referred to by lawmakers as the Working Families Tax Cut Act. You may see one or both names used, but they refer to the same set of tax changes.