Charleston Business Filing Deadlines & Ongoing Requirements

Annual federal income tax return (extensions available via Form 7004 / 4868).

Free, one-time federal tax ID needed for tax filings, payroll and bank accounts.

Businesses holding property that has gone unclaimed — uncashed payroll or vendor checks, customer credits and refunds, unused gift cards, deposits — must report and turn it over to the state each year, after sending the owner a due diligence notice before the deadline. The annual report and payment are due November 1 for general property. A negative report is required even when the business holds nothing. Reports are filed electronically; paper checks are not accepted. The State Treasurer's holder brochure sets the review date at June 30. Which state's law applies depends on the owner's last known address, or the business's state of incorporation when there is none, so a business can owe reports to several states.

A person or service with a physical South Carolina address to receive legal notices and service of process; listed with South Carolina Secretary of State.

Corporate income tax and corporate license fee.

South Carolina business personal property returns are due the last day of the fourth month after the accounting period closes (April 30 for calendar-year filers), to the county auditor or, for retail and sales-tax businesses, the SCDOR. The county's own page was not individually confirmed; the state's guidance applies and the return goes to the county.

Business licenses expire April 30 each year and are renewed on the previous year's gross income; the city's page gives the fee as payable by May 31 with penalties after June 30.

Every South Carolina business needs a local business license under the Business License Tax Standardization Act.

The commercial space must be approved for its intended use before operating.

Withheld income tax, Social Security and Medicare, plus employer share, via EFTPS.

Quarterly reconciliation of wages and payroll taxes.

Annual FUTA return and payment.

Wage statements to employees and transmittal to the SSA.

Employment eligibility verification, retained for 3 years after hire or 1 year after termination.

Employers must post the FLSA minimum wage, FMLA (50+ employees), EEO, OSHA, USERRA and related notices in a conspicuous place.

Employer account for state unemployment insurance contributions.

Withhold state income tax from wages and remit on the assigned deposit schedule; file annual reconciliation and W-2s.

Quarterly wage report and contribution payment. South Carolina taxes the first $14,000 of each employee's wages (2026); new employers pay 1%, and experience-rated rates range from 0% to 5.4%.

Federal law requires reporting each new hire within 20 days of hire (some states require sooner).

South Carolina requires all private employers to use E-Verify for new hires.

State minimum wage, unemployment insurance, workers' compensation and anti-discrimination notices must be posted where employees can see them.

Employers with more than 10 employees keep Forms 300 and 301 for work-related injuries and illnesses, and post the Form 300A summary for the previous year at each establishment from February 1 through April 30. Records are kept five years. Report a work-related fatality within 8 hours and an inpatient hospitalization, amputation or loss of an eye within 24 hours.

Applicable large employers (50 or more full-time employees, counting part-time hours as full-time equivalents) give each full-time employee a Form 1095-C. The January 31 deadline is extended automatically by 30 days, to March 2 in most years (March 1 for the 2026 forms).

The transmittal Form 1094-C and each Form 1095-C are due to the IRS at the end of February on paper or March 31 electronically; employers filing 10 or more information returns in total must file electronically. Penalties apply per late or incorrect form.

Private employers with 100 or more employees file annually through the EEOC's online system; federal contractors with 50 or more employees and certain contracts have also filed. The EEOC sets each year's window (the 2024 report was due June 24, 2025, with no extensions), so check its data collections page.

Establishments with 250 or more employees submit their Form 300A summary through OSHA's Injury Tracking Application by March 2. Establishments with 20 to 249 employees in designated higher-hazard industries must also submit the summary, and those with 100 or more in the most hazardous industries submit Forms 300 and 301 data.

Quarterly estimated payments by owners on business income (Form 1040-ES), including self-employment tax.

Required for each non-employee paid $2,000 or more in the year (payments made after 2025).

Required before making taxable sales; register with the state tax agency.

Collect sales tax from customers and remit on the filing frequency assigned by the state. Local sales taxes are collected and remitted on the same state return; the rate depends on the delivery location.

Home-based businesses need a home occupation permit and must comply with zoning limits (signage, customers, employees).

Articles of Organization (Certificate of Formation/Organization in some states).

Fee: 0.1% (of capital stock and paid-in surplus, plus $15; minimum $25). Required to keep the entity in good standing.