South Carolina Sales Tax Guide for E-commerce Sellers

Rate structure

South Carolina's state rate is 6%; the combined state + local rate ranges from 6–9%. Sourcing: Destination.

COMPONENTRATENOTES

State rate6%MyDORWAY general statewide rate

Local taxes6–9%State 6% + county local option, capital projects and school district taxes by delivery county.

ReturnST-3ST-3 (Sales & Use Tax Return) + ST-389 (local tax schedule by section)

Economic nexus threshold

You must register and collect once your South Carolina sales reach $100,000, measured over the previous or current calendar year. There is no transaction-count threshold. Sales made through a marketplace facilitator do not count toward the remote seller's threshold — only your direct sales do.

Where you stand: SalesTax50 tests your imported sales against this exact rule and flags South Carolina as Approaching or Exceeded on your Nexus page — check my nexus free →

Filing frequency

MyDORWAY assigns a filing frequency at registration based on expected tax liability and adjusts it over time. Frequencies used in South Carolina: Monthly · Quarterly · Annual.

Due dates

Returns are due on the 20th of the month following the period. When the due date falls on a weekend or holiday it moves to the next business day.

Late filing: 5% per month late filing (max 25%) plus 0.5% per month late payment (max 25%), plus interest.

Marketplace facilitator rules

Since April 2019, marketplace facilitators (Amazon, eBay, Walmart, TikTok Shop) collect and remit South Carolina tax on your marketplace sales. How South Carolina treats them:

Who collects?Facilitatoron marketplace orders; you collect on Shopify / your own site.

Count toward nexus?Noonly your direct sales are tested against the remote-seller threshold.

Do you still file?YesYes — a registered seller still files, even for periods where all sales were through marketplaces (a zero or marketplace-only return).

How reported?DeductionDeduction if registered.

Direct salesYou collectShopify, your own site, invoices — you collect and remit on your return.

Marketplace treatment changes state by state and year by year — SalesTax50 separates marketplace and direct sales automatically, but confirm with South Carolina Dept. of Revenue when in doubt.

Filing portal & AutoFile

South Carolina returns are filed through mydorway.dor.sc.gov. Login verification: May require verification. SalesTax50 AutoFile prepares the ST-3 from your imported sales — you review and approve every return before it is submitted.

FAQ

Do I need a South Carolina permit if I only sell on Amazon?

If you exceed the $100,000 threshold with your direct (non-marketplace) sales or have physical presence (including inventory in South Carolina warehouses), yes — you must register even though Amazon collects for you.

What if I sell on Shopify and TikTok Shop?

TikTok Shop collects as a marketplace facilitator; Shopify does not. You collect on Shopify orders and report both streams on your MyDORWAY return — SalesTax50 separates them automatically.

Does SalesTax50 file South Carolina returns automatically?

Yes — AutoFile prepares your ST-3 from imported sales; you approve every return before it is submitted, and a $99 one-time state setup configures your existing South Carolina permit.

This guide is general information for e-commerce sellers, not tax advice. Rates, thresholds and due dates change — confirm with South Carolina Dept. of Revenue before relying on them.

Let AutoFile handle your South Carolina returns

Prepared and checked for you — you approve before anything is filed.

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