Understanding Partnership Taxation in South Carolina

Forming a business partnership in South Carolina can be an efficient way to share capital, effort, and risk. Yet the

tax treatment of partnerships

is fundamentally different from traditional corporations, and misunderstanding these rules can lead to costly errors. This guide explains how South Carolina taxes partnerships, how income flows to partners, and what filings and obligations you should expect at both the state and federal level.

1. What Is a Partnership for Tax Purposes?

For tax law purposes, a partnership generally means an arrangement where

two or more persons carry on a trade or business with the intent to share profits and losses

. This can include traditional general partnerships and many multi-member limited liability companies (LLCs) that are not taxed as corporations.

Key characteristics of partnerships from a tax perspective include:

• Joint operation for profit: Partners collaborate in a common business enterprise and share economic results.
• Separate legal form not required: A partnership may arise by agreement and conduct, even without filing formation documents, unless using specialized structures like limited partnerships or LLPs.
• Pass-through regime: The entity is normally treated as a pass-through, meaning income is not taxed at the partnership level under standard federal rules.

In South Carolina, these entities sit within a broader landscape of business taxation that distinguishes

corporations

, which generally pay tax directly, from

pass-through entities

, whose income flows to individual owners for tax purposes.

2. Pass-Through Taxation: How Partnership Income Flows

Under the conventional regime,

partnerships do not pay federal income tax on business profits

. Instead, the IRS treats the partnership as an information-reporting entity. Profits and losses are allocated among partners according to the partnership agreement (or default rules) and then reported on each partner’s individual return.

South Carolina broadly follows this pass-through model for income taxation, but adds its own rules and an optional entity-level tax election. For most partnerships:

• The partnership files an

  informational tax return

  with the IRS (Form 1065).
• Each partner receives a

  Schedule K-1

  showing their share of income, deductions, credits, and other items.
• Partners report those items on their individual federal and South Carolina income tax returns.

In this way, the tax burden rests on the partners, not the partnership, aligning partnership taxation with the general concept of pass-through entities like S corporations and many LLCs.

3. South Carolina’s Special Rules for Pass-Through Income

South Carolina law distinguishes

active trade or business income

from other categories of income. Active business income from a pass-through entity can be taxed at a

special flat 3% rate

under the South Carolina Income Tax Act.

Key features of South Carolina’s treatment of pass-through business income include:

• 3% rate for active business income: Owners of pass-through entities may have their active trade or business income taxed at 3%, a lower rate than the top marginal rate on other personal income.
• Corporate tax distinction: Traditional C corporations are subject to a separate corporate income tax at a flat 5% rate, rather than pass-through treatment.
• Individual reporting: Even when a special rate applies, the income ultimately appears on the owner’s personal South Carolina tax return.

These rules aim to balance business investment incentives with tax fairness by providing a more favorable rate on income generated directly through active business operations.

4. Required Tax Filings: Federal Form 1065 and South Carolina SC1065

4.1 Federal Partnership Return: Form 1065

At the federal level, partnerships are required to file

Form 1065, U.S. Return of Partnership Income

. This form reports the partnership’s overall income, deductions, and other activity but does not assess tax to the entity.

Important aspects of Form 1065 filing include:

• Annual requirement: Most domestic partnerships with income, deductions, or credits must file annually.
• Schedule K-1 production: The partnership must prepare a K-1 for each partner, detailing that partner’s share of items reported on Form 1065.
• Information-sharing function: The IRS uses the partnership return and K-1s to reconcile what partners report on their individual returns.

4.2 South Carolina Partnership Information Return: SC1065

South Carolina requires every domestic or foreign partnership doing business in the state or owning South Carolina property to file an

SC1065 Partnership Tax Return

.

SC1065 has several functions:

• Reports South Carolina-taxable income: The form identifies the partnership’s income or loss attributable to South Carolina operations.
• Calculates active business income tax at the entity level when applicable: Some partnerships may pay the 3% tax on active trade or business income on this return.
• Supports nonresident withholding calculations: The form incorporates rules requiring withholding on nonresident partners’ shares of South Carolina income.
• Generates SC1065 K-1s: Partnerships prepare state K-1 forms to show each partner’s South Carolina allocation of income, loss, and withholding.

Although SC1065 is an information filing for many partnerships, the presence of entity-level tax options and withholding requirements makes careful completion essential.

5. Partner-Level Reporting and Self-Employment Tax

5.1 Schedule K-1 and Income Allocation

Each partner’s tax burden arises from what appears on their

Schedule K-1

. The K-1 is not filed separately with the IRS—it is attached to the partner’s personal return and used to complete the relevant schedules.

From a practical standpoint, a partner’s K-1:

• Shows the partner’s

  share of ordinary business income

  , capital gains, interest, dividends, and other items.
• Indicates specific deductions and credits allocated to that partner.
• Provides information for computing

  self-employment tax

  , typically via line items tied to partnership trade or business income.

5.2 Self-Employment Tax Obligations

Partners who are

active in the business

frequently owe

self-employment tax

on their share of partnership earnings. Self-employment tax covers Social Security and Medicare contributions normally withheld from employee wages.

Key points about self-employment tax for South Carolina partners include:

• Federal self-employment tax: Partners generally calculate self-employment tax on partnership trade or business income reported from Schedule K-1. This tax is paid in addition to income tax.
• Identification of self-employment income: Schedule K-1 includes designated lines for self-employment income, which feed into the partner’s Schedule SE.
• Impact on estimated payments: Partners may need to make quarterly estimated tax payments to cover both income and self-employment taxes, particularly when wages and withholding are limited.

South Carolina follows federal classifications of self-employment income for its own tax calculations, but the self-employment tax itself is a federal obligation separate from state income tax.

6. Nonresident Partners and Withholding Requirements

Partnerships operating in South Carolina may have

nonresident partners

—individuals or entities that are not South Carolina residents but receive South Carolina-source income through the partnership. The state requires partnerships to

withhold tax on nonresident partners’ shares of taxable South Carolina income

, generally at a 5% rate.

This withholding system serves several purposes:

• Ensures collection of tax on South Carolina-source income: Withholding provides the state with upfront payment toward nonresidents’ tax liabilities.
• Applies to a broad range of partnerships: Domestic and foreign partnerships with nonresident partners and South Carolina income may be subject to these rules.
• Coordinates with partner-level filing: Nonresident partners typically claim the withheld tax as a credit on their South Carolina nonresident return.

SC1065 instructions elaborate on the calculation of taxable income and the applicable withholding, making it important for partnerships to review state guidance when nonresident ownership is involved.

7. Optional Entity-Level Tax Election for Pass-Through Entities

Beginning in 2021, South Carolina law allows certain pass-through entities, including partnerships, to

elect an entity-level tax

on active trade or business income. Under this regime, a qualified entity can choose to have its active business income taxed at the entity level at the same

3% flat rate

applicable to pass-through owners.

Key aspects of the entity-level election include:

• Annual election: The choice can be made on a year-by-year basis and must be executed by the due date of the applicable income tax return, including extensions.
• Qualified entities only: The election applies to certain pass-through entities defined by statute, which may include partnerships meeting specific criteria.
• Interaction with federal law: An entity-level tax can affect partners’ federal deductions and state tax credits, and may be viewed in light of federal limitations on state and local tax (SALT) deductions.

The entity-level regime is intended to offer flexibility and, in some circumstances, potential tax planning opportunities, particularly for owners facing limitations on their deductibility of state taxes at the federal level.

8. Apportionment of Partnership Income and Gain

Partnerships that operate across multiple states must determine what portion of income is

apportioned to South Carolina

. Apportionment relies on statutory formulas and allocation rules that consider factors such as property, payroll, and sales located in the state.

Recent guidance from the South Carolina Department of Revenue illustrates the importance of apportionment in specific transactions, such as the sale of a partnership interest:

• A private letter ruling concluded that a resident individual’s

  gain from the sale of a partnership interest

  could be apportioned based on the partnership’s multi-state activity rather than fully allocated to South Carolina.
• In that case, only the portion of the gain corresponding to the partnership’s South Carolina apportionment percentage—reported as 2.4%—was subject to South Carolina tax.

While private letter rulings formally apply only to the requesting taxpayer, they illustrate how South Carolina may analyze complex partnership-related transactions in an apportionment context.

9. Practical Compliance Checklist for South Carolina Partnerships

To manage partnership tax obligations effectively, South Carolina businesses should adopt a structured compliance approach. Common steps include:

• Obtain an Employer Identification Number (EIN): Partnerships generally must secure an EIN from the IRS for tax filing, even when they have no employees.
• Register with South Carolina tax authorities: Partnerships may need a state tax ID and, if selling taxable goods or services, a sales tax permit with the Department of Revenue.
• File federal Form 1065 annually: Report partnership activity and issue Schedule K-1s to all partners.
• File SC1065: Submit the South Carolina partnership return, compute any active business income tax, and comply with nonresident withholding obligations.
• Maintain a written partnership agreement: Although not filed with the state for general partnerships, a written agreement can clarify income allocations and tax responsibilities.
• Monitor apportionment and multi-state considerations: Track the partnership’s operations across jurisdictions to properly apportion income and gains.

10. Comparison: Partnership vs. Corporation Taxation in South Carolina

Understanding how partnerships differ from corporations is valuable when choosing a business structure. The table below outlines key contrasts in South Carolina:

Feature	Partnership (Pass-Through)	C Corporation
Primary tax level	Partner level; entity usually informational only	Entity level corporate income tax
South Carolina tax rate	Active trade or business income generally taxed at 3% for owners or via entity election	Flat 5% corporate income tax on net income
Federal filing	Form 1065 and partner Schedule K-1	Form 1120 (corporation return)
Double taxation risk	Generally avoided; income taxed once at owner level	Possible taxation of corporate income and shareholder dividends
Self-employment tax	Often applies to active partners on partnership earnings	Not directly; applies to individual wages, not corporate profits

11. Frequently Asked Questions (FAQs)

Q1. Does a South Carolina partnership itself pay state income tax?

By default, a partnership in South Carolina is treated as a

pass-through entity

, so the partnership does not pay income tax on its profits in the conventional sense. Instead, owners report their share and pay tax on their personal returns, often at the 3% rate for active business income. However, some pass-through entities may elect an entity-level tax on active trade or business income at 3%.

Q2. What is SC1065, and who must file it?

SC1065 is South Carolina’s

Partnership Tax Return

. Every domestic or foreign partnership, including applicable multi-member LLCs not taxed as corporations, that does business or owns property in South Carolina generally must file SC1065. The form reports South Carolina-taxable income, calculates any applicable tax, and documents nonresident partner withholding.

Q3. How do partners receive information about their share of income?

Partners receive a

Schedule K-1

from the partnership each year. The K-1 details their share of income, deductions, credits, and other items and is used to complete the partner’s federal and state returns. South Carolina also uses an SC1065 K-1 to show each partner’s share of South Carolina income and withholding.

Q4. Are nonresident partners taxed differently on South Carolina income?

Nonresident partners are taxed on

South Carolina-source income

but may face additional administrative requirements. Partnerships are required to withhold 5% of the South Carolina taxable income of nonresident partners, with the withholding reported and credited against each nonresident partner’s tax liability when they file a South Carolina nonresident return.

Q5. How does selling a partnership interest affect South Carolina taxes?

South Carolina may treat gain from selling a partnership interest as subject to

apportionment

, meaning only the portion of gain corresponding to the partnership’s South Carolina activity is taxed in the state. In a private letter ruling, the Department of Revenue allowed a resident taxpayer to apportion gain based on the partnership’s apportionment percentage, which substantially reduced the taxable amount. Because apportionment rules can be complex, professional tax advice is important for such transactions.