South Carolina — Corporate Income / Franchise Tax

South Carolina imposes an annual corporate income tax at the rate of 5% on the South Carolina taxable income of every corporation transacting, conducting, or doing business within the state, or having income from within the state.

Source: S.C. Code § 12-6-530

The terms "transacting," "conducting," and "doing business" include transacting or engaging in any activity for the purpose of financial profit or gain.

Source: S.C. Code § 12-6-530

The tax applies to any entity taxed as a corporation for federal income tax purposes, regardless of whether these activities are carried on through intrastate, interstate, or foreign commerce. This includes traditional C corporations, limited liability companies that have elected to be taxed as corporations for federal purposes, and other entities that use corporate tax rates federally.

Source: S.C. Code § 12-6-530; SCDOR Corporate Tax Overview

Both domestic corporations (organized under South Carolina law) and foreign corporations (organized under another state's or country's law) that are qualified to do business in South Carolina must file if they meet the activity or income thresholds.

Source: SCDOR Corporate Tax Overview

## Exempt Entities

The following corporations are exempt from the corporate income tax imposed by § 12-6-530:

• Banks as defined in S.C. Code § 12-11-10
• Building and loan associations as defined in S.C. Code § 12-13-10
• Insurance companies
• Nonprofit corporations organized pursuant to Chapter 36 of Title 33 for the purpose of providing water supply and sewage disposal or a combination of those services
• Organizations exempt from income taxes pursuant to S.C. Code § 33-49-120

Source: S.C. Code § 12-6-550

Federal tax-exempt organizations qualifying under Internal Revenue Code §§ 501 through 528 are generally exempt from South Carolina corporate income tax, although their unrelated business income remains subject to tax at the 5% rate.

Source: S.C. Code § 12-6-540; SCDOR Tax Information & Education Document, Chapter 2

## S Corporations

An S corporation that has a valid federal election under Internal Revenue Code Subchapter S is not subject to South Carolina corporate income tax to the extent it would be exempt from federal corporate income tax. Each shareholder must include their share of South Carolina S corporation income on their individual income tax return.

Source: S.C. Code § 12-6-590

S corporations remain subject to the annual corporate license fee (franchise tax) and must file an annual information return (Form SC1120S).

Source: SCDOR S Corporation Information

South Carolina imposes an annual income tax at a flat rate of 5% on the South Carolina taxable income of every corporation transacting, conducting, or doing business within the state or having income within the state.

Source: S.C. Code § 12-6-530

South Carolina requires corporations that do not primarily deal in tangible personal property—including service businesses, financial institutions, contractors, and businesses that install or repair tangible personal property—to apportion their business income to South Carolina using a single gross receipts factor.

Statutory method: Under S.C. Code § 12-6-2290, "if the principal profits or income derived by the taxpayer in South Carolina are not from the sale of tangible personal property, the taxpayer's income must be apportioned to this State by multiplying the net income by a fraction, the numerator of which is the gross receipts from within this State during the income year and the denominator of which is the gross receipts everywhere during the income year." This rule expressly applies to businesses such as service providers, contractors, and others whose primary business is not sales of tangible goods.

Scope of the gross receipts factor: Neither § 12-6-2290 nor § 12-6-2252 specifies detailed sourcing rules for services or financial institutions at the statutory level. The statute itself does not define what constitutes a "South Carolina receipt" for these purposes, nor does it supply industry-specific sourcing mechanics in the way some other states do. Practitioners must refer to the general language of the statute, as interpreted by accompanying regulation or official DOR guidance (none directly cited here), to determine which receipts are sourced to South Carolina.

Contrast with tangible personal property sales: Corporations whose primary business is dealing in tangible personal property must use South Carolina's single-sales-factor formula, as described in S.C. Code § 12-6-2252, which bases apportionment on the ratio of in-state to everywhere sales of tangible goods. Service and financial businesses instead use the "gross receipts" apportionment in § 12-6-2290.

Source: S.C. Code § 12-6-2290 Source: S.C. Code § 12-6-2252

Caution / review status: Not yet human confirmed. The statute does not supply detailed definitions or sourcing rules for each business type; application may depend on subsequent regulation or Department guidance.

South Carolina corporate taxable income begins with federal taxable income as determined under the Internal Revenue Code. This federal amount is then modified as specified in Article 9 of Chapter 6 (covering additions and subtractions to gross income, adjusted gross income, and taxable income) and is subject to allocation and apportionment rules in Article 17 of Chapter 6.

Source: S.C. Code § 12-6-580; S.C. Code § 12-6-1110

South Carolina corporate income tax returns must be filed on or before the 15th day of the fourth month following the close of the taxable year. For calendar-year C corporations, this means returns are due April 15.

Fiscal-year corporations. C corporations with fiscal tax years other than December 31 must file by the 15th day of the fourth month after their fiscal year ends. For example, a corporation with a fiscal year ending June 30 must file by October 15.

Foreign corporations without U.S. offices. Returns for foreign corporations that do not maintain an office or place of business in the United States must be filed on or before the 15th day of the sixth month following the taxable year.

Extension of time to file. South Carolina grants an automatic extension of time for filing a corporate income tax return. The Department of Revenue accepts a federal extension: if the corporate return is received within the time as extended by the IRS, it satisfies the South Carolina filing deadline. A corporation may also file Form SC1120-T, Application for Automatic Extension of Time to File Corporation Tax Return, to request an extension directly from South Carolina. The South Carolina Department of Revenue states that payment of the balance due through MyDORWAY (the Department's online portal) automatically submits a filing extension request without requiring a separate form.

Extension to file, not to pay. The extension applies only to the deadline for filing the return. Any tax due must still be paid by the original due date—the 15th day of the fourth month following the close of the taxable year. Paying the estimated balance by the original deadline is necessary to avoid penalties and interest on any unpaid tax.

Annual report and license fee timing. Corporations must file an annual report (Schedule D, part of Form SC1120) and pay the corporate license fee. Unless otherwise provided, corporations must file the annual report on or before the 15th day of the fourth month following the close of the taxable year, the same deadline as the income tax return. The annual report and license fee may be extended in the same manner that corporate income tax returns are extended for federal income tax purposes.

Source: S.C. Code § 12-6-4970

Source: S.C. Code § 12-20-20

Source: SCDOR C Corporation Filing Requirements

Source: SCDOR Corporate Tax Overview

South Carolina imposes an annual corporate license fee on every corporation required to file an annual report with the South Carolina Department of Revenue. The corporate license fee is deemed to be a tax for purposes of administrative and enforcement provisions of Title 12. While the statute uses the term "corporate license fee," practitioners commonly refer to this levy as a franchise tax.

Rate and Calculation

The annual license fee is $15.00 plus $1.00 for each $1,000 (or fraction thereof) of capital stock and paid-in or capital surplus of the corporation, as shown by the records of the corporation on the first day of the taxable year in which the annual report is filed. In no case may the license fee be less than $25.00. The license fee must be paid on or before the original due date for filing the annual report—the 15th day of the fourth month following the close of the taxable year, which for calendar-year corporations is April 15.

Measurement of Capital Stock and Paid-In or Capital Surplus

For purposes of calculating the license fee, capital stock and paid-in or capital surplus is the amount reported on the taxpayer's "applicable financial statement." The applicable financial statement is a statement covering the taxable year, selected in the following priority order: (a) a statement required to be filed with the Securities and Exchange Commission; (b) a certified audited balance sheet used for credit purposes, shareholder reporting, or another substantial nontax purpose; (c) a balance sheet required to be provided to a federal, state, or local government entity; or (d) a balance sheet used for credit purposes, shareholder purposes, or any other purpose. If a taxpayer has statements described in more than one category, the applicable financial statement is the statement with the lowest designation in the priority list.

Who Must Pay

South Carolina law requires every domestic corporation (incorporated under South Carolina law), every foreign corporation (incorporated under another state's or country's law) qualified to do business in South Carolina, and any other corporation required by S.C. Code § 12-6-530 to file income tax returns to file an annual report and pay the corporate license fee. Because S.C. Code § 12-2-25 provides that for purposes of Title 12 the term "corporation" includes a limited liability company taxed for South Carolina income tax purposes as a corporation, LLCs classified as corporations for federal income tax purposes must pay the South Carolina corporate license fee.

S corporations that have a valid federal election under Internal Revenue Code Subchapter S remain subject to the annual corporate license fee and must file an annual report, even though they are not subject to South Carolina corporate income tax on their net income.

Apportionment for Multistate Corporations

If a corporation's business is conducted partly within and partly outside South Carolina, the corporation may prorate the license fee in the same manner and on the same basis as its net income is apportioned under S.C. Code §§ 12-6-2250 through 12-6-2295. However, the minimum license fee of $25.00 may not be apportioned.

Combined Returns

When a combined income tax return is filed, the license fee is measured by the total capital and paid-in or capital surplus of each corporation considered separately, without offset for investment of one corporation in the capital or surplus of another corporation in the group. The minimum license fee of $25.00 applies to each corporation in the combined group.

Initial License Fee

A domestic corporation must file an initial annual report and pay the minimum license fee of $25.00 with the Secretary of State when it files its initial articles of incorporation. A foreign corporation must file an initial annual report and pay the minimum license fee when it files its application for certificate of authority with the Secretary of State. A corporation that does not file an application for certificate of authority with the Secretary of State but is required to file a South Carolina income tax return must file the initial annual report and pay the minimum license fee to the Department of Revenue on or before 60 days after initially doing business, or using a portion of its capital, in South Carolina.

Utilities and Electric Cooperatives

Certain companies—including express companies, street railway companies, navigation companies, waterworks companies, power companies, electric cooperatives, light companies, gas companies, telegraph companies, and telephone companies—pay a different license fee under S.C. Code § 12-20-100 in place of the fee imposed by § 12-20-50. For these companies, the license fee is based on the fair market value of property owned and used within South Carolina and gross receipts derived from regulated business within the state, rather than on capital stock and paid-in or capital surplus.

Credit Reduction

License fees may be reduced by credits provided in S.C. Code § 12-6-3410 (job development credit) or § 12-6-3480 (headquarters credit).

Source: S.C. Code § 12-20-50

Source: S.C. Code § 12-20-60

Source: S.C. Code § 12-20-70

Source: S.C. Code § 12-20-20

Source: S.C. Code § 12-20-40

Source: S.C. Code § 12-20-100

Source: S.C. Code § 12-20-160

Source: S.C. Code § 12-20-175

Source: S.C. Code § 12-2-25

South Carolina imposes a corporate income tax filing obligation (nexus) when a corporation has a sufficient connection to the state—this includes economic nexus in the absence of physical presence. The South Carolina Department of Revenue confirms that, for Income Tax purposes, economic nexus alone is generally sufficient to create nexus, even without a physical presence. For example, nexus may be triggered by:

• Employees, agents, brokers, representatives, or subcontractors conducting any activity—ranging from solicitation to performing services—for any duration within South Carolina.
• The presence of tangible property in the state, such as goods, offices, vehicles, or real estate.

Source: South Carolina DOR, “Nexus” for Income Tax

Regarding federal Public Law 86‑272 (15 U.S.C. § 381), South Carolina expressly recognizes its limited safe harbor: it applies only if

1. The sole in‑state activity is the solicitation of orders for tangible personal property;
2. Such orders are sent out‑of‑state for acceptance or rejection;
3. If accepted, they are filled by shipment or delivery from a point outside South Carolina.

Under those conditions, the state may not impose income tax on those sales. Source: South Carolina DOR, “Nexus” for Income Tax – PL 86‑272 section

However, this protection is narrow. If a taxpayer engages in activities beyond protected solicitation—such as performing services, maintaining property, or having representatives act in roles beyond mere solicitation—PL 86‑272 protection is lost, and nexus is established. The Department has further defined the boundaries of protected versus nexus‑creating activities in its formal guidance, including:

• Revenue Ruling 97‑15 – Protected Activities under PL 86‑272
• Revenue Ruling 16‑11 – Nexus‑Creating Activities for Income Tax

Source: South Carolina DOR, “Related Revenue Rulings” list

Caution / review status: Not yet human confirmed.

South Carolina imposes no state-specific time limitation on the carryforward of corporate Net Operating Losses (NOLs). Instead, the state conforms to federal NOL carryforward rules as provided in the Internal Revenue Code (IRC). South Carolina allows the federal NOL carryforward period—20 years for losses arising in years prior to 2018 and indefinite (subject to federal taxable income limitations) for losses arising after 2017 under IRC § 172. Importantly, the state does not allow NOL carrybacks at all, regardless of federal treatment.

The South Carolina Department of Revenue's official instructions confirm: “South Carolina follows the federal NOL carry‑forward period, but no carry‑backs are allowed.” The Department's Corporate FAQs similarly state that "Net operating loss (NOL) carrybacks are not allowed. Only carry forwards are allowed" and that "there is not a limited amount or percentage a corporation can carry forward to the next tax year."

This corrects prior references to a fixed “15-year carryforward period.” That rule applies to certain South Carolina tax credits, not to corporate NOLs. South Carolina corporate NOLs conform to IRC § 172 as adopted by the state—with no independent state limitation and no carrybacks.

Source: SCDOR SC1120 Instructions Source: SCDOR Corporate FAQs Source: SCDOR Credit Periods

South Carolina requires corporations to make estimated income tax payments if the expected tax liability for the taxable year (after credits and withholding) is $1,000 or more. The requirement and payment schedule closely mirror the federal system, with state-specific details set out in statute and the Department of Revenue’s corporate estimated tax guidance.

Threshold for Estimated Payments Corporations must remit estimated tax if their anticipated South Carolina corporate income tax (after credits and withholding) is at least $1,000. No estimated payments are required if the liability falls below this level. The threshold and obligation are established in S.C. Code § 12-6-3910(A) and confirmed in SCDOR Estimated Tax FAQs. Source: S.C. Code § 12-6-3910

Installment Due Dates Payments must generally be made in four equal installments:

• 15th day of the fourth month of the taxable year
• 15th day of the sixth month
• 15th day of the ninth month
• 15th day of the twelfth month (typically Dec. 15 for calendar filers)

Fiscal-year corporations follow these intervals based on their year-end. The schedule aligns with the federal system. See S.C. Code § 12-6-3910(C)-(D) and SCDOR Estimated Tax FAQ. Source: S.C. Code § 12-6-3910

Short Period Returns For taxable periods less than 12 months, due dates are adjusted. The first installment is due by the 15th day of the fourth month of the short period, with later payments at equal intervals. Department guidance is included with the SC1120-CDP declaration form. Source: SCDOR Corporate Declaration of Estimated Income Tax (SC1120-CDP)

How to Pay—Payment Methods and Required Forms Corporations must generally pay estimated tax electronically through the MyDORWAY portal unless specifically exempted by the Department (e.g., due to lack of internet access). Form SC1120-CDP is used when making payments by check or claiming exception from the e-payment requirement. See instructions on the form or SCDOR Estimated Tax FAQ for details. Source: SCDOR Corporate Estimated Tax FAQ Source: SCDOR Corporate Declaration of Estimated Income Tax (SC1120-CDP)

Penalty for Underpayment and Safe Harbors Corporations failing to make timely estimated tax payments may be liable for an "addition to tax" penalty unless an exception applies. A safe harbor applies if payments equal at least 100% of the prior year’s tax (if that year was a full 12 months with a positive tax liability) or 100% of the current year’s tax, paid in four timely installments. See S.C. Code § 12-6-3910(D) and SCDOR FAQ for safe harbor specifics and limitations. Penalty calculation mechanics are spelled out in S.C. Code § 12-6-3910 and referenced Department guidance. Source: S.C. Code § 12-6-3910 Source: SCDOR Corporate Estimated Tax FAQ

Note on sources: The prior link to the SC1120-T Instructions is not currently available from an official .gov site as of 2026-06-17. The SC1120-CDP and current DOR FAQs contain the latest official guidance for estimated payment mechanics.

Caution / review status: Not yet human confirmed. Statute and forms last reviewed 2026-06-17; Departmental guidance may be periodically updated at SCDOR’s corporate estimated tax FAQ and forms page.

South Carolina imposes both penalties and interest for late filing or late payment of corporate income tax returns and corporate license fees.

1. Penalties

• Late filing penalty: 5% of the unpaid tax or fee for each month—or part of a month—the return is late, up to a maximum of 25%. The statute makes clear that any part of a month counts as a full month (i.e., even one day late in a month triggers the full month's penalty).
• Late payment penalty: 0.5% of the unpaid amount for each month—or part of a month—the payment is late, also capped at 25%. Both penalties may run concurrently if both the filing and payment are late for the same period.

Source: SC Code § 12-54-43

2. Interest Interest accrues on any unpaid balance of corporate income tax or license fee from the original due date until paid. The interest rate is set quarterly to match the federal underpayment rate under IRC § 6621. Under the statute, interest applies only to the unpaid tax or fee, not to unpaid penalties. By law, the Department may waive up to 30 days' interest for administrative convenience, but otherwise interest is not abated.

Source: SC Code § 12-54-25

3. Scope and Applicability These penalty and interest rules apply to both late-filed or late-paid South Carolina corporate income tax and corporate license fee obligations. The South Carolina Department of Revenue FAQ confirms that the same penalty regime (including the "month or part thereof" application and the rates above) applies to both the corporate income tax return (SC1120) and the corporate license fee return (CL-1 and annual reports).

Source: SCDOR Corporate FAQs

4. Example and Calculations For example, if a corporation owes $10,000 in income tax and files and pays both the return and tax 32 days after the due date (crossing into the second month):

• Late filing penalty: $10,000 × 5% × 2 months = $1,000 (since any part of the second month counts as a full month)
• Late payment penalty: $10,000 × 0.5% × 2 months = $100
• Interest: Calculated at the federal underpayment rate, applied to the unpaid $10,000 (but not accrued penalties), for the period the amount remains unpaid

Neither SCDOR nor the statutes provide day-by-day breakdowns or compounding specifics; the law applies the full penalty for each month or part of a month late, and interest is calculated on the unpaid tax or fee only, not on penalties. If additional practitioner detail is required (such as daily accrual or compounding), the current public sources do not address this.

Source: SCDOR Corporate FAQs

Caution / review status: Not yet human confirmed. Example calculations are illustrative; statutory rules should be confirmed in edge cases or for nuanced scenarios.

In South Carolina, a corporation has a corporate income tax filing obligation if it is "transacting, conducting, or doing business" in the state—or if it has income sourced to South Carolina, regardless of whether it maintains a physical presence. The South Carolina Department of Revenue (SCDOR) applies both physical and economic nexus principles: a corporation establishes nexus (and a filing obligation) through activities such as having employees, representatives, or property in South Carolina, or by deriving income from sources within the state, even if those activities are conducted solely by remote or third-party actors.

Statutory Basis and Administrative Interpretation: S.C. Code § 12-6-530 subjects to tax "every corporation transacting, conducting, or doing business within this State, or having income within this State," regardless of whether the corporation is domestic or foreign. The law sets no quantitative threshold (such as a sales or income dollar amount); rather, the existence of business activity—broadly defined to include solicitation, sales, or other profit-driven activity—triggers nexus.

The SCDOR Nexus guidance further confirms that a corporation need not have a physical presence (such as in-state employees or offices) to create nexus. Economic nexus is sufficient, and includes deriving income attributable to South Carolina sources or engaging representatives or agents—however briefly—within the state. Revenue Ruling 16-11 provides additional examples of in-state activities that create nexus (including non-exempt services, installations, or warranty work).

Public Law 86-272—Solicitation-Only Safe Harbor: South Carolina also recognizes the federal limitation on state authority imposed by Public Law 86-272 (15 U.S.C. § 381): a corporation whose only activity in South Carolina is the solicitation of orders for sales of tangible personal property, where such orders are sent outside the state for approval and are filled by shipment/delivery from outside the state, is protected from state net income tax (including income-measured franchise tax). If a corporation’s South Carolina activities go beyond protected solicitation (for example, accepting returns, providing services, or engaging in post-sale activities) this immunity is lost, and nexus is established. Detailed boundaries between protected and nexus-creating activity are addressed in Revenue Ruling 97-15 and clarified in SCDOR guidance.

Source: S.C. Code § 12-6-530 Source: South Carolina DOR "Nexus" for Income Tax Source: South Carolina DOR, "Public Law 86-272 and South Carolina Income Tax" Source: South Carolina DOR, Revenue Ruling 16-11

Caution / review status: Not yet human confirmed.

South Carolina computes corporate taxable income by starting with federal taxable income, with modifications (additions and subtractions) outlined in Article 9 of Chapter 6, Title 12 of the South Carolina Code. The statutory authority for these modifications is S.C. Code § 12-6-1130, which provides that South Carolina does not automatically conform to every federal adjustment and instead follows its own prescribed rules.

1. Disallowance of Deductions Related to Certain Tax-Exempt Income S.C. Code § 12-6-1120(1) requires an addition to income for any deduction that was disallowed under IRC § 265 for federal purposes, except that the deduction is allowed to the extent the related income is taxable by South Carolina. The statute provides: "There must be added to taxable income amounts which... were deducted for federal income tax purposes under the Internal Revenue Code but not allowed for state purposes by reason of the taxable status of the related income in South Carolina."

2. State and Local Income, Franchise, or Net Income Taxes Under S.C. Code § 12-6-1130(3), no deduction is allowed for state or local income, franchise, or net income-based taxes (including South Carolina corporate license fees). “Deductions permitted by Section 164(a) of the Internal Revenue Code for taxes based on, measured by, or computed with reference to income or profits and paid or accrued to a state or a political subdivision of a state, or to any foreign country, are not allowed as a deduction.”

3. S Corporation Specific Adjustments S.C. Code § 12-6-590 refers to additional modifications for S corporations, including excess net passive income (IRC § 1375), built-in gains (IRC § 1374), and deferred LIFO recapture (IRC § 1363). The SC1120I instructions clarify that these amounts (as reflected on the federal return) must be appropriately reported and modified for South Carolina purposes. (See SC1120I Instructions, 2025, pages 2–3, "Line 1 – Federal Ordinary Income (Loss)").

Federal Items Not Explicitly Addressed in SC Statute or Guidance As of June 16, 2026, South Carolina’s statutes and official instructions do not explicitly address adjustments for the following items:

• IRC § 163(j) interest expense limitation
• Federal bonus depreciation
• IRC § 78 gross-up
• GILTI (IRC § 951A)

A review of S.C. Code §§ 12-6-1120 through 12-6-1170 and the official SC1120 and SC1120I instructions found no reference to these items; the official position or specific treatment cannot be confirmed in primary authority as of this date.

Source: S.C. Code § 12-6-1120 Source: S.C. Code § 12-6-1130 Source: S.C. Code § 12-6-590 Source: SC1120I Instructions, pp. 2–3

Caution / review status: Not yet human confirmed. Unable to confirm official SC position on some federal tax modifications due to statutory/guidance silence as of 2026-06-16.

Direct answer: South Carolina requires an out-of-state corporation to file and pay corporate income tax if it is "transacting, conducting, or doing business within this State, or having income within this State," even if there is no physical presence. Public Law 86-272 protects only sellers of tangible personal property whose in-state activities are strictly limited to solicitation of orders, with all orders approved and shipped from outside South Carolina.

Why: S.C. Code § 12-6-530 establishes that any corporation "transacting, conducting, or doing business" or "having income within" South Carolina is subject to corporate income tax. The statute does not require a physical presence; the state's Department of Revenue (SCDOR) explicitly recognizes that economic presence, including deriving income from South Carolina customers, creates nexus. The SCDOR says, "Economic nexus is generally sufficient to create nexus even without a physical presence" for income tax purposes. There is no stated economic threshold (such as a minimum sales dollar amount)—any degree of regular in-state economic activity may trigger a filing obligation, as determined by SCDOR guidance and rulings.

Federal Public Law 86-272 (15 U.S.C. §§ 381–384) limits a state's imposition of net income tax on out-of-state sellers whose only in-state activity is soliciting orders for sales of tangible personal property. South Carolina follows this standard: PL 86-272 immunity applies only where activities are strictly limited to protected solicitation, orders are sent outside the state for approval, and fulfillment is from outside the state.

Source support:

• S.C. Code § 12-6-530 provides: "There is imposed annually an income tax... on the South Carolina taxable income of every corporation transacting, conducting, or doing business within this State, or having income within this State, whether the corporation is domestic or foreign."

Source: S.C. Code § 12-6-530

• The SCDOR affirms: "Economic nexus is generally sufficient to create nexus even without a physical presence."

Source: South Carolina DOR – Nexus for Income Tax

• Revenue Ruling 97-15 and Revenue Ruling 16-11 give examples of protected vs. unprotected activities under PL 86-272. Activities that are only solicitation of orders for tangible property are protected; activities such as taking orders for services, providing post-sale assistance, or engaging in delivery within the state are not. SCDOR explicitly states that PL 86-272 "does not apply to sales or solicitation of intangibles or services."

Source: South Carolina DOR, Revenue Ruling 97-15 Source: South Carolina DOR, Revenue Ruling 16-11 Source: South Carolina DOR – Public Law 86-272

Caution / review status: Not yet human confirmed. The statute and DOR guidance do not provide a quantitative sales/activity threshold; DOR has not published a Wayfair-like bright-line for income tax nexus as of 2026-06-17.

South Carolina corporate income tax starts with federal taxable income but requires several state-specific additions and subtractions before arriving at the South Carolina tax base. These adjustments are governed by S.C. Code §§ 12-6-1120 (gross income modifications) and 12-6-1130 (taxable income modifications).

Key recurring additions and subtractions:

1. State and local tax deduction add-back: Corporations must add back any deduction taken on the federal return for state or local income, franchise, or net income-based taxes, including the South Carolina corporate license fee, per S.C. Code § 12-6-1130(3). "Deductions permitted by Section 164(a) of the Internal Revenue Code for taxes based on, measured by, or computed with reference to income or profits and paid or accrued to a state or a political subdivision... are not allowed as a deduction." Source: S.C. Code § 12-6-1130(3)

2. Net operating loss (NOL) adjustments: South Carolina allows carryforwards (up to 15 years), but does not permit NOL carrybacks, even if allowed federally. See S.C. Code § 12-6-1130(8): "A federal election to carry back a net operating loss does not affect South Carolina income tax purposes." Source: S.C. Code § 12-6-1130(8)

3. Interest and dividends: Interest on U.S. government obligations (such as U.S. Treasury bonds) included in federal taxable income is subtracted from South Carolina income [S.C. Code § 12-6-1120(1)]. Interest from state/local bonds outside SC is generally not subtracted. For dividends, no subtraction is available unless otherwise provided by statute. "There must be subtracted... [i]nterest on obligations of the United States and its possessions[,] to the extent included in gross income for federal income tax purposes." Source: S.C. Code § 12-6-1120(1)

4. Domestic Production Activities Deduction (IRC § 199): Any deduction claimed for domestic production activities must be added back. "An amount equal to any deduction for domestic production activities as permitted by IRC Section 199... must be added to taxable income." (S.C. Code § 12-6-1130(13)). Source: S.C. Code § 12-6-1130(13)

5. Other recurring adjustments:

• No deduction for federal income taxes paid or accrued [S.C. Code § 12-6-1130(6)].
• Limitation or disallowance of certain deductions relating to exempt interest/dividends [S.C. Code § 12-6-1120(1), (5)].
• Adjustments for charitable contributions that do not comply with state rules [S.C. Code § 12-6-1130(12)].
• Add-back for reductions to basis under IRC § 50(c) [S.C. Code § 12-6-1130(9)].
• Add-back for certain business credits disallowed at the federal level (e.g., IRC § 280C limitations) [S.C. Code § 12-6-1130(7)].

Areas of statutory/administrative silence: As of 2026-06-17, neither published statute nor official instructions directly addresses South Carolina’s treatment of the IRC § 163(j) business interest limitation, GILTI (IRC § 951A), or IRC § 78 gross-up. Statutory silence means these may require further review or guidance as law and regulations evolve.

Source: S.C. Code § 12-6-1120 Source: S.C. Code § 12-6-1130

Caution / review status: Not yet human confirmed. Statutory citations refer to the most frequently encountered recurring modifications as of 2026-06-17; practitioners should verify for recent legislative updates for specialized cases.

South Carolina permits—but does not require—certain corporate groups to elect to file a consolidated income tax return. The state does NOT mandate unitary combined reporting and has not adopted federal consolidated return mechanics for state tax purposes.

Eligibility and Exclusions A South Carolina consolidated return may be filed only by an “affiliated group of corporations” as defined in S.C. Code § 12-6-5020: a parent and one or more subsidiaries where the parent owns at least 80% of the voting stock, or several corporations under the "substantially entire control" of the same interests. All included corporations must:

• Be subject to South Carolina corporate income tax;
• Have the same taxable year;
• Exclude S corporations, banks, and certain savings and loan associations (statutory exclusions).

S.C. Code § 12-6-5020(A), (B), (E) specifically bar S corporations, banks (see S.C. Code § 12-11-10), and building and loan associations from filing on a consolidated basis. Source: S.C. Code § 12-6-5020

Election Mechanics and Duration The election to file a consolidated return is made on the corporation’s annual return (by checking the appropriate box on SC1120) and is binding for five years unless the Department of Revenue (SCDOR) allows a change for good cause. Once made, the consolidated filing status applies to all members for five years; a group may return to separate filing only with SCDOR permission or after the binding period expires.

• “An election made under this section must be for a period of not less than five taxable years, and applies to all members of the affiliated group that are subject to income tax in this State.” (See § 12-6-5020(C)). The SCDOR FAQs confirm this five-year commitment and outline the need for Department approval to terminate early.

Source: S.C. Code § 12-6-5020(C) Source: SCDOR Corporate FAQs

Computation and Mechanics South Carolina does not follow federal consolidated return mechanics. Instead, each eligible corporation computes its federal taxable income individually, applies any South Carolina additions/subtractions, then apportions or allocates its income per state law. The consolidated return then sums each member’s South Carolina taxable income (or loss). Credits, net operating losses, and other income attributes are NOT generally pooled across the group, except as specifically permitted by statute or SCDOR ruling. Investments of one member in another are not eliminated in the South Carolina return. These technical distinctions are explained in SCDOR Revenue Procedure 16-1. Source: SCDOR Revenue Procedure 16-1 Source: S.C. Code § 12-6-5020(F)

Anti-Avoidance and Combined/Unitary Filing South Carolina does not require mandatory unitary combined reporting; there is no “water’s-edge” or worldwide unitary group reporting regime. Only voluntary consolidated returns by qualified affiliated groups are permitted. The SCDOR has the authority to require separate returns if a consolidated return does not properly reflect a group’s income attributable to South Carolina, but does not mandate combined reporting based solely on relatedness or intercompany transactions. This position is confirmed both in statute and in SCDOR’s published guidance (FAQ and Rev. Proc. 16-1). Source: S.C. Code § 12-6-5020(F) Source: SCDOR Corporate FAQs

Summary:

• Only C corporations in a qualified affiliated group may elect consolidation;
• Election is binding for five years;
• Computation is on a member-by-member basis (not federal or unitary combined);
• South Carolina does NOT require combined/unitary reporting or water’s-edge combination.

Source: S.C. Code § 12-6-5020 Source: SCDOR Corporate FAQs Source: SCDOR Revenue Procedure 16-1

Review status: Not yet human confirmed.