SC2220: Underpayment of Estimated Tax by Corporations (2024)

South Carolina · South Carolina DOR · Used for tax years 2024

South Carolina Form SC2220 determines whether a corporation paid enough income tax during 2024 and calculates any penalty for underpayment of estimated tax. It shows required installments, payments or credits for each period, and any underpayment or overpayment.

Who files this form

For tax year 2024, corporations with an Income Tax liability of $100 or more must prepay their tax through withholding or Estimated Tax payments. This includes S Corporations, LLCs taxed as corporations, and tax-exempt organizations subject to unrelated business Income Tax. Use SC2220 to determine whether enough tax was paid during the year and whether an underpayment penalty applies.

You must file SC2220 with your corporation’s tax return, even if no penalty is due, if you check a Part II box for:

  • The adjusted seasonal installment method.
  • The annualized income installment method.
  • A large corporation calculating its first required installment based on the prior year’s tax.

If total tax on line 1 is less than $100, do not complete SC2220. You do not owe a penalty.

When it's due

For the 2024 tax year, enter these Estimated Tax installment due dates in columns A through D of line 7:

  • The 15th day of the 4th month of the corporation’s tax year.
  • The 15th day of the 6th month.
  • The 15th day of the 9th month.
  • The 15th day of the 12th month.

For the penalty calculation on line 17, use the payment date or the 15th day of the 4th month after the tax year closes, whichever is earlier. SC1120S filers use the 3rd month instead; SC990-T filers use the 5th month.

What you'll need

Have the following information available:

  • The corporation’s name and FEIN.
  • Its 2024 Income Tax return and total tax amount: SC1120 line 11, SC1120S line 12, SC1120U line 9, SC1104 line 9, SC1101B line 7, or SC990T line 9.
  • Its 2023 Income Tax return, if using the prior year’s tax, including tax after credits and any overpayment elected to be applied to 2024 Estimated Tax.
  • Estimated Tax payment amounts and payment dates.

If using the adjusted seasonal or annualized income installment method, use the federal forms, worksheets, and instructions with the necessary South Carolina adjustments. Attach a copy of the worksheet to SC2220.

Large corporations and S Corporations should refer to the federal Form 2220 instructions for the amounts specified in the SC2220 instructions.

How to file

Attach SC2220 to your Income Tax return. If you use the adjusted seasonal or annualized income installment method, also attach a copy of the worksheet.

Enter the total penalty from line 36 on line 17 of SC1120, or the comparable line of another Income Tax return.

The supplied text does not provide a mailing address or e-file instructions.

Common mistakes

  • Leaving out SC2220 when no penalty is due. If any Part II box is checked, you must file it with your tax return anyway.
  • Using an ineligible prior-year tax amount. Skip line 2 if the 2023 tax was zero, no return showing a tax amount was filed, or the 2023 tax year was shorter than 12 months. Use line 1 on line 3 instead.
  • Missing a payment credit. Include any 2023 overpayment you elected to apply to 2024 Estimated Tax on line 9.
  • Completing the columns in the wrong order. Complete lines 10 through 16 for one column before moving to line 10 of the next column.
  • Omitting the method label or worksheet. If using a special installment method, write “adjusted” or “annualized” to the left of line 8 and attach the worksheet.
  • Skipping the penalty calculation. If any column has an underpayment on line 15, complete Part IV.

Questions people ask

What is the required installment if no Part II boxes apply?

Enter 25% of line 3 in each column of line 8.

Can seasonal or uneven income reduce the penalty?

Possibly. The adjusted seasonal installment method or annualized income installment method may lower required installments. Using either method may lower or eliminate the penalty.

Can a 2023 overpayment count toward 2024 Estimated Tax?

Yes, if you elected to apply that overpayment to 2024 Estimated Tax. Include it in the payments on line 9.

Where can I find the quarterly rates marked with an asterisk?

Use the penalty interest rate for each calendar quarter. The SCDOR determines these rates during the first month of the preceding quarter and publishes them in quarterly Information Letters at dor.sc.gov/policy.

Official sources

All versions of SC2220