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How to file South Carolina sales tax

2026 due dates, filing frequencies, form ST-3, and official filing resources.

State returnST-3
Monthly returns due20th of the month following the period
Filing frequenciesMonthly, Quarterly, Annual
Rules verifiedJuly 2, 2026

When is South Carolina sales tax due?

Monthly South Carolina sales tax returns are due the 20th of the month following the period. Quarterly returns are due the 20th of the month following the period (calendar quarters). When a due date lands on a weekend or federal holiday it moves to the next business day; the 2026 calendar on this page already applies that adjustment.

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South Carolina sales tax due dates for 2026

Every date below comes from the state's published deadline rule (dataset 2026.07.0) and is already moved to the next business day when it lands on a weekend or federal holiday. Your account's assigned filing frequency decides which table applies.

Monthly South Carolina sales tax due dates

Rule: 20th of the month following the period.

PeriodPeriod endsReturn due
January 2026Jan 31, 2026Feb 20, 2026
February 2026Feb 28, 2026Mar 20, 2026
March 2026Mar 31, 2026Apr 20, 2026
April 2026Apr 30, 2026May 20, 2026
May 2026May 31, 2026Jun 22, 2026 (moved: 2026-06-20 falls on a Saturday)
June 2026Jun 30, 2026Jul 20, 2026
July 2026Jul 31, 2026Aug 20, 2026
August 2026Aug 31, 2026Sep 21, 2026 (moved: 2026-09-20 falls on a Sunday)
September 2026Sep 30, 2026Oct 20, 2026
October 2026Oct 31, 2026Nov 20, 2026
November 2026Nov 30, 2026Dec 21, 2026 (moved: 2026-12-20 falls on a Sunday)
December 2026Dec 31, 2026Jan 20, 2027

Quarterly South Carolina sales tax due dates

Rule: 20th of the month following the period (calendar quarters).

PeriodPeriod endsReturn due
Q1 2026Mar 31, 2026Apr 20, 2026
Q2 2026Jun 30, 2026Jul 20, 2026
Q3 2026Sep 30, 2026Oct 20, 2026
Q4 2026Dec 31, 2026Jan 20, 2027

Annual South Carolina sales tax due dates

Rule: January 20 following the calendar year.

PeriodPeriod endsReturn due
Calendar year 2026Dec 31, 2026Jan 20, 2027
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South Carolina filing notes

No additional state-specific filing notes are recorded for this cadence set.

Return and form

The principal repository-tracked return is ST-3. Paper eligibility is taxpayer-specific; electronic filing or a waiver may control.

Tracked form version: Rev. 3/31/23

Paper filing posture: taxpayer specific

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File South Carolina sales tax from reviewed data, not spreadsheets

Prophit.ai tracks every South Carolina due date above inside the return workspace, builds the period from your transaction data, and produces worksheet for portal entry that a reviewer approves before anything is submitted.

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Need every state at once? Download the 2026 sales tax filing calendar (CSV + ICS, all states, weekend/holiday-adjusted).

Workflow support does not by itself establish registration, filing authority, credentials, agency acceptance, or tax advice. Confirm your assigned filing frequency with the state.

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South Carolina sales tax filing questions

01When is South Carolina sales tax due?

Monthly South Carolina sales tax returns are due the 20th of the month following the period. Quarterly returns are due the 20th of the month following the period (calendar quarters). When a due date lands on a weekend or federal holiday it moves to the next business day; the 2026 calendar on this page already applies that adjustment.

02How often do you file sales tax in South Carolina?

South Carolina assigns a filing frequency to each account. The published cadences are monthly, quarterly and annual filing; the state assigns the frequency based on tax volume and notifies the account, so confirm the assigned basis before relying on a calendar.

03What form is used to file South Carolina sales tax?

The South Carolina return tracked here is ST-3. The principal repository-tracked return is ST-3. Paper eligibility is taxpayer-specific; electronic filing or a waiver may control.

04What happens if a South Carolina due date falls on a weekend or holiday?

The due date moves to the next business day. In 2026, 3 of the South Carolina due dates listed on this page are adjusted for a weekend or federal holiday; each adjusted date is marked in the calendar.

05Can South Carolina sales tax be filed on paper?

Paper filing posture tracked for South Carolina: taxpayer specific. The principal repository-tracked return is ST-3. Paper eligibility is taxpayer-specific; electronic filing or a waiver may control.

Reviewed and current as of August 22, 2026. Read the full South Carolina sales tax guide for rates, sourcing, products, exemptions, and marketplace rules.