Lowcountry Kayak Outfitters has thirteen South Carolina sales-tax dates, three of them on a weekend the Department does not explain

The moment

Lowcountry Kayak Outfitters is a kayak and paddle shop in Beaufort, South Carolina: boats, paddles, dry bags and a rental fleet, sold to locals and to the people who come for the marsh tours. Dana Whitfield bought it in 2019. It has three W-2 employees besides Dana, it is taxed as an S corporation, and it collects South Carolina sales tax at the register. It is the third of October, the slow season is starting, and Dana is writing next year's dates on the office wall.

What they did instead

Dana's habit was the 20th. Sales tax, the 20th, every month. That is the rule the Department publishes. It fails in 2026 on three dates, because June 20 is a Saturday and September 20 and December 20 are Sundays. The Department's page lists the 20th and does not say whether a weekend date moves to Monday. So the habit has no answer, and the usual one is to pay on the Friday before. June 19 is Juneteenth, a federal holiday, which makes that Friday a poor one to count on.

The questions a CFO asks first

1. How many South Carolina dates does the shop have in the next year, and which of them fall on a weekend?
2. Does the Department say what a weekend does to the date?
3. What changes if South Carolina has the shop on a quarterly schedule instead of monthly?
4. What does the sheet leave off, and does the entity type change what South Carolina adds?

The arithmetic, shown

Seven engine runs, all through the tool's own engine, all built on Lowcountry's profile: an S corporation, three W-2 employees, no 1099 contractors, South Carolina as the state, registered to collect South Carolina sales tax.

Scenario one: monthly, the schedule the shop is on. The Department of Revenue's sales-tax page lists each period and its due date. Read across the second half of the year it states

> May 31, due June 20; June 30, due July 20; July 31, due August 20; August 31, due September 20; September 30, due October 20; October 31, due November 20; November 30, due December 20; December 31, due January 20.

The tool returns twenty-six dated line items. Thirteen are South Carolina sales-tax returns, January 2026 through January 2027, every one on the 20th. Three are South Carolina estimated tax on the owner's own return. The other ten are federal: the owner's four estimates, four Form 941 payroll returns, Form 940 and the W-2s.

Three of the thirteen sales-tax dates are weekend days: Saturday

> 2026-06-20

and Sundays

> 2026-09-20

and

> 2026-12-20

The tool does not move them. It shows them as published and tells the owner why:

> The Department's schedule lists the 20th and doesn't say on that page whether a weekend date moves to the next business day, so the dates are shown as published; confirm the weekend ones with the Department.

That is the opposite choice from a state that publishes a weekend rule. Here the tool will not invent a Monday. For Dana, three dates on the wall carry a question mark, and the Department is the place to settle it. The last return, for December, is

> 2027-01-20

a Wednesday, so it needs no note.

The estimates are the second thing to see. The Department's notice says

> You must make estimated payments if you expect to owe an Income Tax liability of $100 or more when filing your South Carolina Individual Income Tax return.

and the tool lists three dates: April 15, June 15 and September 15, 2026. There is no January 2027 line. The tool says why:

> the January 2027 installment isn't on a page this run could read, so it isn't listed.

So the sheet has three South Carolina estimate dates and four federal ones, and the fourth federal date, January 15, 2027, stands alone.

The crowding is on the estimate days. April 15, June 15 and September 15 each carry two items, the federal estimate and the South Carolina one. February 2 carries three, the fourth-quarter Form 941, Form 940 and the W-2s. None of those shares a day with a sales-tax return. The sales-tax dates are the 20th and the payroll and estimate dates are not.

Scenario two: quarterly. The tool returns seventeen items, not twenty-six, with four South Carolina returns dated 2026-04-20, 2026-07-20, 2026-10-20 and 2027-01-20. Nine fewer lines, and none of the four is a weekend, so the weekend note does not appear. The Department states

> You must request approval from the SCDOR to file quarterly or annually.

so the shop cannot choose this schedule for itself.

Scenario two (b): a schedule the tool does not date. Annual, something else or not sure all come out the same. The tool returns thirteen items: the federal ones and the three South Carolina estimates, no sales-tax date at all. It says

> This tool doesn't compute a specific date for a South Carolina sales-tax filing frequency other than monthly or quarterly, or one that isn't confirmed.

and sends the owner to the MyDORWAY account for the schedule South Carolina assigned.

Scenario two (c): no South Carolina sales tax. If the shop did not collect it the tool returns the same thirteen items. Which is a reminder that the sales-tax lines are thirteen of twenty-six in Scenario one, half the sheet.

Scenario three: the frequency not yet confirmed. With everything else answered and the filing frequency left blank, the tool does not guess. It returns a named refusal: missing: ["how often South Carolina has this business file sales tax"]. Nothing computes until there is an answer.

Scenario four: the identical profile as a calendar-year C corporation. The tool returns twenty-five items, not twenty-six. Federal Form 1120 and four Form 1120-W deposits arrive in place of the owner's four estimates, and one South Carolina line arrives in place of the three estimates: the corporate return. The Department's corporate page states

> file annually on or before the 15th day of the fourth month after the close of the taxable year

For a calendar-year corporation that is

> 2026-04-15

and April 15 then carries three items: Form 1120, the first Form 1120-W deposit and the South Carolina return. The thirteen sales-tax returns do not move. Fourteen South Carolina lines in all, and no South Carolina corporate estimate, because the tool found no Department page that gives a schedule.

Scenario four (b): the same corporation, tax year unconfirmed. Mark the tax year as not calendar-year, or as unconfirmed, and the tool returns nineteen items. Six dates disappear: Form 1120, the four 1120-W deposits and the South Carolina return. The thirteen sales-tax returns stay. The tool gives the reason:

> This tool only computes a South Carolina corporate return date for a calendar-year C corporation (tax year January-December).

What changed

Dana has thirteen South Carolina sales-tax dates on the same sheet as the federal payroll and estimated-tax dates. The 20th on the wall is right for ten of the thirteen. The numbers to watch are three and three: three returns that land on a weekend the Department does not explain, and three South Carolina estimates where the federal schedule has four. The first three are the ones to confirm with the Department. The second three are a gap in what the tool could read, and it says so.

What the tool will not do

It will not decide which schedule the shop is on. The Department approves quarterly and annual filing, so the tool asks and builds dates from the answer. It will not move a weekend date to Monday on a guess. It will not compute the tax owed on any return or installment. And for Lowcountry specifically, the sheet is shorter than the real year. The tool's own note says what is off it:

> This tool doesn't cover South Carolina withholding, pass-through returns (S corporation and partnership), corporate estimated payments, the annual sales-tax return, or local and accommodations taxes.

That is not a statement that none are due. Lowcountry is an S corporation and the sheet shows no South Carolina entity return for it. South Carolina withholding on three people's wages is not on the sheet either, nor is local tax. The tool does not ask whether a South Carolina estimated payment is owed at all, so the three dates show the schedule that would apply if one is. It will not know about an extension, a payment plan or a penalty already assessed on any date above. This tool supports a named list of states, which the state picker in the tool shows, and every line above is the plain due date for the entity type it was told about.