What Is Unrelated Business Income?

The Three-Part Test, in Plain Terms

The IRS defines unrelated business income using three conditions that all have to be met for a given activity's income to count. First, the income has to come from a "trade or business," generally meaning an activity carried on to produce income from selling goods or services, the same basic definition used elsewhere in tax law. Second, the activity has to be "regularly carried on," meaning it's conducted with a frequency and continuity similar to how a comparable commercial business would run it, not as an occasional, one-off event. Third, the activity has to be "not substantially related" to the organization's exempt purpose, meaning it doesn't contribute importantly to accomplishing that purpose beyond simply raising money for it. Missing any one of the three means the income isn't unrelated business income at all, regardless of the other two.

Example: A Museum Gift Shop

A museum's gift shop selling exhibit catalogs, replicas, and other items related to its collection generally supports the museum's educational purpose directly, so that income is typically treated as substantially related, not unrelated. The same gift shop selling generic souvenirs or unrelated merchandise, run with regular hours alongside the museum's regular operations, is a clearer example of income likely to be treated as unrelated, since the goods themselves don't contribute to the museum's educational mission the way exhibit-related items do.

Example: Renting Out Space

A nonprofit that rents out unused office space or a hall it owns is often, but not automatically, outside unrelated business income, since rent from real property is one of the common exclusions described below. The exclusion can narrow, though, if the property was purchased with debt still being paid off, or if the rent is structured to depend on the tenant's income or profits rather than a fixed amount, which can pull the income back into taxable territory under separate debt-financed-property rules.

Example: Advertising in a Nonprofit's Publication

Advertising sold in a nonprofit's magazine or newsletter is a frequently cited example of unrelated business income, since selling ad space is generally treated as a trade or business distinct from the organization's editorial or educational content, even when the publication itself furthers the exempt purpose. The editorial content and the advertising income inside the same publication are often analyzed separately for exactly this reason.

What's Excluded Even When It Looks Like a Business

Several categories of income and activity are excluded from unrelated business income even when they would otherwise meet the three-part test:

• Passive investment income, including most dividends, interest, royalties, and rents from real property, unless the asset producing it was debt-financed.
• Volunteer-run activities, where substantially all the work is performed by volunteers rather than paid staff.
• Convenience activities, such as a hospital cafeteria operated mainly for patients, visitors, and staff rather than the general public.
• Donated-merchandise sales, such as a thrift shop selling items that were substantially all donated to the organization.

Each exclusion turns on specific facts, such as what share of labor is genuinely volunteer, so an activity that resembles one of these examples isn't automatically excluded without checking the details against your actual operations.

Why the Definition Matters Even Before You Owe Any Tax

Understanding what counts as unrelated business income matters before you reach the point of calculating tax, because it determines which of your organization's revenue streams need separate tracking in your books in the first place. An organization with $1,000 or more of gross income from an activity meeting all three conditions has to file Form 990-T and generally owes tax on that income above its allowable deductions; for the filing mechanics, estimated tax requirements, and that $1,000 threshold in detail, see unrelated business income tax for nonprofits.

Document the Facts Behind Any Exclusion You're Relying On

Whether an activity qualifies as volunteer-run, a convenience activity, or donated-merchandise sales often comes down to a specific, checkable fact, such as the actual share of volunteer versus paid labor. Keep records supporting the exclusion at the time, not a general impression reconstructed later.

Review New Revenue Ideas Against the Three-Part Test Before Launching Them

Before starting a new revenue stream, such as renting out space, selling merchandise, or running a members-only service to the public, check it against the three-part test and the common exclusions first, so you know from day one whether to track it separately for tax purposes.

"Substantially Related" Can Turn on How an Activity Is Run, Not Just What It Is

Two organizations selling the same product can land on different sides of the related/unrelated line depending on whether the sale itself furthers an exempt purpose or merely raises money for one. A gift shop tied to an exhibit's educational content is treated differently than a gift shop selling generic souvenirs, even inside the same building.

This Is Not Tax Advice

Applying the three-part test and its exclusions to your organization's specific activities requires a close look at the facts. A tax professional experienced with exempt organizations can review a planned or existing revenue stream before you assume it's taxable or excluded.