UBIT applies to both IRAs & Solo 401k plans.
Since IRAs and Solo 401ks are tax-deferred retirement accounts, they are not subject to federal or state taxes until distributions start, which is usually when the account holder retires. The funds can be invested in businesses, so they are in direct competition with non-retirement account investors who also want to invest in active businesses but have to pay capital gains tax. This is seen as unfavorable to tax-paying businesses and investors who use their non-retirement funds for these ventures. To help keep things on par, the IRS requires IRAs and Solo 401k plans that purchase equity in an LLC, for example, to pay UBIT on the net income generated from the investment if the business is deemed to be engaging in an “active” business as oppose to a “passive” investment business. For example, a Solo 401k that generates net income from an investment in a gift shop will be subject to UBIT because the gift shop is considered to be an active business and not a passive investment, such as a long-term real estate holding.
Key facts about UBIT/UBTI
UBIT is paid only on income of $1,000 or more from a trade or business.
UBIT is reported to the IRS on Form 990-T, Exempt Organization Business Income Tax Return, which must be filed in addition to the annual information return.
UBIT falls under IRC Sec 511, and exceptions are found in Publication 598, Tax on Unrelated Business Income of Exempt Organizations.
UBIT must be paid with Solo 401k funds, not personal funds.
Estimated tax must be paid if the tax-exempt entity expects its tax for the year to be $500 or more.
Unrelated Debt-Financed Income (UDFI) Tax applies to IRAs, but not to Solo 401ks.
As described above, while tax-deferred accounts, such as IRAs and Solo 401ks are usually subject to paying UBIT if they purchase equity in an “active” business, another tax known as Unrelated Debt-Financed Income (UDFI) only applies to IRAs, not to Solo 401ks. Debt financing comes into play when an IRA or Solo 401k uses a loan in conjunction with funds in the retirement account to invest in real estate. Click here to learn more about UDFI, and here for information about non-recourse loans.
Additional Information: Unrelated Business Income Tax | Internal Revenue Service (irs.gov)