Credit card processing and merchant services in Charleston, SC

Charleston County's sales tax is 9%, three full points above South Carolina's 6% state rate. The Department of Revenue's ST-500 chart, effective May 1, 2026, lists the county's total and the local taxes behind it. You may have read that counties can add a 1% local tax with voter approval. That's true as far as it goes, but Charleston County stacks more than one local tax, so a terminal set to 7% would undercharge every customer.

The chart is organized by county, not by city. Match each address to its county before you set a rate, and check again when you open a second location.

The Census Bureau estimated Charleston's population at 159,423 in July 2025. Here's how the numbers stack at a register. A $200 purchase carries $18 in tax at 9%. Add a 3% credit card surcharge and that's another $6, so the customer pays $24 over the sticker price. South Carolina has no surcharge statute we've found, which leaves the card networks' rules: Visa's 3% cap, Mastercard's 4%, nothing on debit, and notice at the entrance, at checkout and on the receipt.

If you sell prepared food or rent rooms, ask the City and the County which local fees apply on top of sales tax before you set up your POS.

We'd look at processing cost before adding any fee. Interchange-plus pricing shows each card's real cost, our POS terminals take chip, tap and swipe at the counter or the table, and a free statement review shows what you pay today.