Quarterly Estimated Tax Calculator — South Carolina (2026)
If you earn income in South Carolina without withholding — freelancing, contracting, rentals, dividends — the IRS expects payment four times a year, not once. This calculator turns your expected 2026 net profit into a per-quarter number covering self-employment tax, federal income tax and South Carolina state tax. South Carolina uses a progressive income tax with 3 brackets running from 0.00% up to 6.20%, applied after a state standard deduction of $16,100.
South Carolina Quarterly Tax Calculator
Gross 1099 income minus business expenses.
2026 due dates and safe harbor
Federal estimated payments are due April 15, June 15, September 15 of 2026 and January 15 of 2027. You avoid penalties by paying either 90% of the current year's liability or 100% of last year's (110% if prior-year AGI exceeded $150,000) — the safe-harbor rule.
South Carolina runs its own estimated-payment schedule that usually mirrors the federal dates. On $90,000 of net profit the South Carolina portion alone is about $882 per quarter.
Underpayment penalties
The IRS charges interest-style penalties per quarter you fall short, currently around 7–8% annualized. Paying late in the year does not fix an early-quarter shortfall unless you use the annualized income method on Form 2210.
Irregular income is common in automotive work around Charleston: if Q1 is slow and Q4 is huge, the annualized method usually beats four equal payments.
Paying as a South Carolina taxpayer
Pay federally through IRS Direct Pay or EFTPS, and South Carolina through the state revenue department's online portal — keep confirmation numbers for both.
South Carolina has no separate city or county income tax, so the state figure above is the full sub-federal income tax you pay.
Local and payroll taxes South Carolina adds on top
South Carolina adds no state-mandated employee payroll deduction beyond FICA, so nothing extra is taken from your gross pay at the state level.
South Carolina has no separate city or county income tax, so the state figure above is the full sub-federal income tax you pay.
Nobody withholds these for you when you are self-employed in South Carolina. Local wage taxes, city business licences and gross-receipts style levies are yours to register for and remit alongside your quarterly federal and state estimates.
Working across a state line from South Carolina
South Carolina has no income-tax reciprocity agreements, so if you live here and work across a state line you generally file a nonresident return in the work state and claim a credit at home to avoid double taxation.
Remote and hybrid work complicates this further: most states tax income where the work is physically performed, so a Charleston resident spending part of the year at a client site in North Carolina may owe a nonresident return there. Keep a day-count log if you split time between states.
The rest of your South Carolina tax bill
South Carolina charges a 6% state sales tax, homeowners pay an average effective property tax of 0.57% of market value, and the minimum wage in force during 2026 is $7.25 an hour.
Local option taxes bring most areas to 7%–9%.
Income tax is only one part of a state's take. South Carolina recovers revenue through sales and property tax as well, which is why headline income tax rates alone are a poor guide to how far a salary really goes. South Carolina exempts Social Security and offers a $10,000 retirement deduction plus a $15,000 senior deduction at 65+.
South Carolina vs North Carolina on the same salary
On a $90,000 salary, a single filer keeps about $68,222 a year in South Carolina against roughly $68,669 in North Carolina — a difference of $447, or $37 a month.
Effective combined rates are 24.2% in South Carolina and 23.7% in North Carolina. Set that gap against living costs: index 95 here versus 96 there, with property tax at 0.57% and 0.8% respectively.
South Carolina income tax brackets 2026 (single filer)
| Taxable income | Rate |
|---|---|
| $0 – $3,460 | 0.00% |
| $3,460 – $17,330 | 3.00% |
| $17,330 and up | 6.20% |