What South Carolina tax interest rate applies through September 30, 2024, and what rate is paid on eligible refunds?

Plain-English summary

South Carolina's listed tax interest rate is 8% for October 1, 2023 through September 30, 2024. It applies to tax underpayments and overpayments under S.C. Code Ann. § 12-54-25 and is generally compounded daily — the one exception is an underpayment of declaration of estimated tax, which uses simple interest.

The rate the Department pays on eligible refunds is lower. For fiscal year 2024-2025 (July 1, 2024 through June 30, 2025), Budget Provisos 41.2 and 117.81 require a three-percentage-point reduction from the listed rate, dropping the 8% rate to 5% for eligible refunds in that fiscal year. The letter also includes the Department's historical rate table back to September 1, 1985.

What this means for you

If you owe South Carolina tax

Use 8% to estimate interest on an underpayment during this period; because it compounds daily, the exact charge depends on the balance and days outstanding.

If you are owed a refund

Don't assume the full 8% — eligible refund interest is reduced by three points to 5% in fiscal year 2024-2025.

Estimated-tax underpayments

These use simple interest rather than daily compounding.

Common questions

Q: What is the listed rate through September 30, 2024?
A: 8%.

Q: Is the interest compounded?
A: Generally daily; simple interest applies to underpayments of declaration of estimated tax.

Q: Does an eligible refund earn the full 8%?
A: No — it is reduced by three percentage points to 5% for fiscal year 2024-2025.

Citations and references

• S.C. Code Ann. § 12-54-25 (2014) — interest on underpayments and overpayments
• S.C. Code Ann. § 12-4-320; SC Revenue Procedure #09-3 — authority
• 2024 S.C. Act No. 226, Provisos 41.2 and 117.81 — three-point reduction in eligible refund interest, FY2024-2025

Source

• Landing page: https://dor.sc.gov/advisory-opinion-search
• Original PDF: https://dor.sc.gov/sites/dor/files/policies/IL24-11.pdf

Original ruling text

STATE OF SOUTH CAROLINA

DEPARTMENT OF REVENUE
300A Outlet Pointe Blvd., Columbia, South Carolina 29210
P.O. Box 125, Columbia, South Carolina 29214-0575

SC INFORMATION LETTER #24-11
SUBJECT:

Interest Rate

DATE:

July 25, 2024

REFERENCE:

S.C. Code Ann. Section 12-54-25 (2014)
2024 S.C. Act No. 226, Provisos 41.2 and 117.81

AUTHORITY:

S.C. Code Ann. Section 12-4-320 (2014)
SC Revenue Procedure #09-3

SCOPE:

An Information Letter is a written statement issued to the public to announce general
information useful in complying with the laws administered by the Department. An
Information Letter has no precedential value.

The interest rate to be applied to underpayments and overpayments* of taxes is listed below. The rate is
compounded daily except simple interest applies to the underpayment of declaration of estimated tax.
Period

Rate*

Period

09/01/85 – 12/31/85
01/01/86 – 06/30/86
07/01/86 – 09/30/87
10/01/87 – 12/31/87
01/01/88 – 03/31/88
04/01/88 – 09/30/88
10/01/88 – 03/31/89
04/01/89 – 09/30/89
10/01/89 – 03/31/91
04/01/91 – 12/31/91
01/01/92 – 03/31/92
04/01/92 – 09/30/92
10/01/92 – 06/30/94
07/01/94 – 09/30/94
10/01/94 – 03/31/95
04/01/95 – 06/30/95
07/01/95 – 03/31/96
04/01/96 – 06/30/96
07/01/96 – 03/31/98

11%
10%
9%
10%
11%
10%
11%
12%
11%
10%
9%
8%
7%
8%
9%
10%
9%
8%
9%

04/01/98 – 12/31/98
01/01/99 – 03/31/99
04/01/99 – 03/31/00
04/01/00 – 03/31/01
04/01/01 – 06/30/01
07/01/01 – 12/31/01
01/01/02 – 12/31/02
01/01/03 – 09/30/03
10/01/03 – 03/31/04
04/01/04 – 06/30/04
07/01/04 – 09/30/04
10/01/04 – 03/31/05
04/01/05 – 09/30/05
10/01/05 – 06/30/06
07/01/06 – 12/31/07
01/01/08 – 03/31/08
04/01/08 – 06/30/08
07/01/08 – 09/30/08
10/01/08 – 12/31/08

Rate*
8%
7%
8%
9%
8%
7%
6%
5%
4%
5%
4%
5%
6%
7%
8%
7%
6%
5%
6%

Period
01/01/09 – 03/31/09
04/01/09 – 12/31/10
01/01/11 – 03/31/11
04/01/11 – 09/30/11
10/01/11 – 03/31/16
04/01/16 – 03/31/18
04/01/18 – 12/31/18
01/01/19 – 06/30/19
07/01/19 – 06/30/20
07/01/20 – 03/31/22
04/01/22 – 06/30/22
07/01/22 – 09/30/22
10/01/22 – 12/31/22
01/01/23 – 09/30/23
10/01/23 – 09/30/24

Rate*
5%
4%
3%
4%
3%
4%
5%
6%
5%
3%
4%
5%
6%
7%
8%

*Note reduction of interest rate on refunds. For fiscal year 2024-2025 (July 1, 2024, through June 30,
2025), Budget Provisos 41.2 and 117.81 direct the Department to reduce the rate of interest paid on eligible
refunds by a total of three percentage points from the above listed rates.