Partnership Tax Guide for Small Business

Quick Answer: How Are Partnerships Taxed?

A partnership is a pass-through entity — the business itself does not pay federal income tax. Instead, income, deductions, credits, and other tax items “pass through” to the individual partners, who report their share on their personal tax returns. The partnership files an information return (Form 1065) and issues Schedule K-1 to each partner detailing their allocated share.

This pass-through structure avoids the double taxation that C corporations face, but it comes with its own complexity: basis tracking, guaranteed payments, self-employment tax, and special allocation rules that require careful compliance.

Who Must File Form 1065?

Any U.S. business treated as a partnership for federal tax purposes must file Form 1065 annually. This includes:

• General partnerships (GPs)
• Limited partnerships (LPs)
• Limited liability partnerships (LLPs)
• Multi-member LLCs that have not elected corporate tax treatment (the default classification for multi-member LLCs is partnership)

Filing deadline: Form 1065 is due on the 15th day of the 3rd month after the partnership’s tax year ends. For calendar-year partnerships, this is March 15. A 6-month extension (Form 7004) pushes the deadline to September 15.

Penalties for late filing: The IRS imposes a penalty of $245 per partner per month (up to 12 months) for partnerships that file Form 1065 late. For a partnership with four partners filing three months late, that’s $2,940 in penalties — before any interest on unpaid tax.

Schedule K-1: The Partnership’s Core Document

Schedule K-1 (Form 1065) is the partnership equivalent of a W-2 — it reports each partner’s distributive share of income, deductions, credits, and other tax items. Every partner receives one, and the amounts flow to their individual tax return (Form 1040).

Three boxes on Schedule K-1 matter most for small business partners:

Box 1 — Ordinary Business Income (Loss): The partner’s share of the partnership’s ordinary operating income or loss. This amount goes on Schedule E of Form 1040 and is generally subject to self-employment tax.

Box 4 — Guaranteed Payments: Payments to partners for services or the use of capital, made without regard to partnership income. These are treated as ordinary income to the recipient partner and are deductible by the partnership. Critically, guaranteed payments are subject to self-employment tax even if the partnership reports a loss.

Box 19 — Distributions: Cash and property distributed to the partner during the year. These are generally tax-free to the extent of the partner’s outside basis — they’re a return of capital, not taxable income (unlike corporate dividends).

Partner Basis: The Foundation of Partnership Tax

A partner’s outside basis (or tax basis) determines how much loss they can deduct, whether distributions are taxable, and the gain or loss recognized on sale of the partnership interest. Every partner must track their basis — the partnership does not report it on the K-1 (though it may provide a supplemental basis schedule).

Outside Basis Calculation

Initial basis: Cash contributed + adjusted basis of property contributed - liabilities assumed by partnership + partner’s share of partnership liabilities

Annual adjustments:
+ Share of taxable income (including tax-exempt income)
+ Additional capital contributions
+ Increase in share of partnership liabilities
- Distributions of cash and property
- Share of nondeductible expenses
- Share of losses and deductions
- Decrease in share of partnership liabilities

Critical rule: A partner cannot deduct losses in excess of their outside basis. Excess losses are suspended and carried forward to future years when basis is restored. This is one of the most common audit triggers — partners claiming losses without sufficient basis.

Self-Employment Tax for Partners

General partners and active LLC members must pay self-employment tax (15.3% — 12.4% Social Security up to the wage base, plus 2.9% Medicare) on their distributive share of partnership income. Limited partners are generally exempt from self-employment tax on their distributive share (but not on guaranteed payments for services).

The self-employment tax calculation flows through Schedule SE attached to the partner’s Form 1040. For a partner with $100,000 of ordinary business income from the partnership, the self-employment tax is approximately $15,300 — significant enough to require quarterly estimated tax payments to avoid underpayment penalties.

For a deeper look at this topic, see our self-employment tax guide for small business.

Guaranteed Payments: Compensation for Active Partners

Guaranteed payments compensate partners for services or capital contributed, regardless of whether the partnership generates income. They serve as the partnership equivalent of a salary — but unlike W-2 wages, guaranteed payments are not subject to payroll tax withholding (FICA, FUTA, or income tax withholding).

The partner reports the guaranteed payment as ordinary income on Schedule E and pays self-employment tax on it through Schedule SE. The partnership deducts it as a business expense on Form 1065.

Section 199A — Qualified Business Income Deduction

Partners (including LLC members taxed as partners) may qualify for the 20% Qualified Business Income (QBI) deduction under Section 199A. This is one of the most valuable tax benefits of operating as a partnership. Eligible partners can deduct up to 20% of their QBI from the partnership, subject to limitations based on W-2 wages paid by the partnership and the unadjusted basis of qualified property.

For 2026, the phase-out begins at taxable income of $191,950 (single) or $383,900 (married filing jointly). Above these thresholds, the deduction may be limited or eliminated for specified service trades or businesses (SSTBs). For a complete walkthrough, see our Section 199A pass-through deduction guide.

Special Allocations and Substantial Economic Effect

One of the advantages of the partnership structure is flexibility in allocating income and deductions among partners. Unlike corporations (where dividends are proportional to stock ownership), partnerships can make special allocations — provided they have “substantial economic effect” under Treasury Regulation §1.704-1.

To pass muster, a special allocation must:

• Be reflected in the partnership agreement
• Be based on capital account maintenance rules
• Include a liquidation-in-accordance-with-capital-accounts provision
• Have economic consequences that actually affect the partners’ economic positions

The IRS scrutinizes allocations that appear to be purely tax-motivated (e.g., allocating all depreciation deductions to the high-bracket partner while allocating income to the low-bracket partner).

Hot Assets and Section 751

When a partner sells their partnership interest or receives a disproportionate distribution, “hot assets” (unrealized receivables and substantially appreciated inventory) must be separately accounted for. The portion of gain attributable to hot assets is treated as ordinary income, not capital gain.

This is a trap for the unwary: a partner selling their interest for a gain of $200,000 might assume it’s all long-term capital gain (taxed at 20% maximum), only to discover that $50,000 is recharacterized as ordinary income (taxed at up to 37%) because of hot assets in the partnership.

Tax Year Considerations

Partnerships must generally adopt a required tax year — either the tax year of the majority partners (more than 50% interest) or, if no majority interest tax year exists, the tax year of all principal partners (5% or more interest). If neither rule produces a tax year, the partnership uses the tax year that results in the least aggregate deferral of income.

A fiscal year-end other than December 31 is possible but requires establishing a business purpose to the IRS’s satisfaction — the Section 444 election provides some relief but requires periodic payments approximating the tax deferral benefit.

Reporting Requirements and Common Pitfalls

IRS Form 8308

If a partner sells their partnership interest, the partnership must file Form 8308 to report the sale, including the selling partner’s information and the date of transfer. Failure to file can result in penalties.

State-Level Filing Obligations

Partnerships operating in multiple states may need to file returns in each state where they have nexus. Some states impose entity-level taxes or fees on partnerships (e.g., California’s $800 annual LLC fee, Texas’s franchise tax). Plan for these obligations as part of your overall tax planning strategy.

Basis Tracking

The IRS increasingly expects partners to report basis consistently on Form 1040. Starting in recent years, Schedule K-1 instructions strongly encourage partnerships to provide basis information to partners. Maintain detailed basis schedules for every partner — this is the number one area where partnerships fail in an audit.

Key Takeaways

• Partnerships are pass-through entities: the partnership files Form 1065 (informational), and income/loss flows to partners via Schedule K-1.
• The filing deadline for calendar-year partnerships is March 15 — with penalties of $245 per partner per month for late filing.
• General partners pay self-employment tax (15.3%) on their distributive share of ordinary income; limited partners are generally exempt.
• Guaranteed payments are taxable to the recipient partner and deductible by the partnership — always subject to self-employment tax.
• Outside basis determines loss deductibility, distribution taxability, and gain/loss on sale of interest — track it meticulously.
• The Section 199A QBI deduction provides up to a 20% deduction on qualified partnership income, subject to income thresholds and SSTB limitations.
• Special allocations require substantial economic effect — the IRS will reallocate tax items if allocations lack economic substance.

Operating as a partnership offers genuine tax advantages — no double taxation, flexible allocations, and the QBI deduction — but the compliance burden is real. Work with a qualified CPA who understands partnership taxation inside and out, and make sure your basis schedules are audit-ready before the IRS comes asking.