Form 990-W Instructions: Estimated Tax Worksheet for Nonprofits

Form 990-W is the IRS worksheet a tax-exempt organization uses to estimate its unrelated business income tax for the year and break that liability into four quarterly payments. You keep the completed worksheet in your records; it is never filed. Only the payments themselves go to the IRS, and they are required if your projected tax on unrelated business income reaches $500 for the year.¹

Who Needs to Use the Worksheet

Any organization exempt under Internal Revenue Code Section 501(a) that earns income from an activity unrelated to its exempt purpose may owe Unrelated Business Income Tax. That covers 501(c)(3) charities, 501(c)(6) trade associations, and nearly every other 501(c) entity, along with state colleges, universities, and their wholly owned subsidiaries.² Exempt trusts are also in scope, including IRAs, SEP IRAs, SIMPLE IRAs, Roth IRAs, Coverdell education savings accounts, Archer MSAs, and health savings accounts, on any unrelated business income they generate.³

Run the numbers on Form 990-W first. If your projected tax for the year comes in under $500, no estimated payments are required. You may still have to file Form 990-T at year-end, because that filing obligation starts when gross unrelated business income reaches $1,000, which is a separate threshold.⁴ Mixing those two numbers up is one of the more common errors.

Private foundations also use Form 990-W, but to estimate the Section 4940 excise tax on net investment income rather than UBIT. The worksheet mechanics are similar; the underlying tax is a different one.

Estimating Unrelated Business Taxable Income

The heart of the worksheet is a projection of Unrelated Business Taxable Income: what your organization expects to earn from any trade or business regularly carried on and not substantially related to its exempt purpose. Think advertising revenue in a nonprofit magazine, income from a museum shop selling unrelated merchandise, or fees from a university parking garage open to the public. Start with gross income from those activities and apply the exclusions and deductions the Code allows.

What Comes Out of the Calculation

Several categories of passive income are excluded from UBTI entirely: dividends, interest, annuities, royalties, and the deductions directly connected to earning them. Rents from real property are excluded too, but that exclusion drops away if the rent depends on the tenant’s income or profits (other than a fixed percentage of receipts) or if more than half the rent comes from personal property bundled into the lease.⁵ Gains and losses from selling property are generally excluded as well, unless the property was held primarily for sale to customers.

All of those exclusions get overridden for debt-financed property. If the organization borrowed to acquire an investment, income from that investment is pulled back into UBTI in proportion to the outstanding debt, even if it would otherwise count as excluded dividends, interest, or rent. When you project income on the worksheet, check each investment for acquisition debt before assuming the usual exclusions apply.

Siloing Multiple Activities

If the organization runs more than one unrelated trade or business, UBTI is calculated separately for each one under IRC Section 512(a)(6). A loss from one unrelated activity cannot offset income from another.⁵ Each silo’s UBTI floors at zero; nothing negative carries across. The silo totals are added together, and only then do you apply the $1,000 specific deduction. Organizations typically identify each activity with a two-digit NAICS code, and that classification must stay consistent year to year.

Prior-Year Losses

A net operating loss from an earlier year can reduce current-year UBTI from the same activity. For losses arising in tax years beginning after December 31, 2017, the deduction is capped at 80% of taxable income computed before the NOL itself, and these losses carry forward indefinitely but cannot be carried back.⁶ Older losses from tax years beginning before January 1, 2018 are not subject to the 80% cap, so apply them first. Because of siloing, post-2017 NOLs can only offset income from the same activity that produced them, which means tracking loss history silo by silo.

Deductions and the $1,000 Floor

Ordinary business expenses directly connected to an unrelated activity are deductible against its income: salaries, supplies, depreciation, rent on space used for the activity. Expenses shared between exempt and unrelated activities require a reasonable allocation. Charitable contributions are deductible whether or not they connect to the unrelated business. After all modifications and deductions, subtract a flat $1,000 specific deduction from aggregate UBTI.⁵ That $1,000 is excluded when computing NOLs, so you cannot use it to inflate a loss.

Applying the Tax Rate

Most exempt organizations compute the tax at the flat 21% corporate rate, because IRC Section 511(a) directs that UBIT be figured at the rates that apply to regular corporations.⁷ Exempt trusts are the exception. They use the trust and estate rate schedule, which has compressed brackets reaching 37% at relatively low income levels.⁸ Check the IRS inflation-adjusted brackets for the year in question; the threshold shifts annually.

Subtract any estimated tax credits you expect to claim, such as the general business credit. What remains is the net estimated tax liability. Under $500, no estimated payments are required.

Figuring the Required Annual Payment

The required annual payment is the lesser of two figures: 100% of the current year’s estimated net tax, or 100% of the tax shown on the prior year’s Form 990-T, provided the prior year was a full 12-month period and showed a tax greater than zero.¹ The prior-year number is a safe harbor: match it and no underpayment penalty applies, even if the current year ends up higher.

A separate rule applies to large organizations. An organization is “large” if it (or a predecessor) had taxable income of $1,000,000 or more in any of the three tax years immediately preceding the current year. A large organization can use the prior-year safe harbor only for the first installment. Every installment after that must be based on 100% of current-year estimated tax, and any shortfall from using the prior-year method on installment one gets added to installment two.⁹

Divide the required annual payment by four. Each quarterly installment is 25% of that amount.

When Income Is Uneven

Organizations with seasonal, event-driven, or otherwise fluctuating income can use the annualized income installment method instead of paying four equal quarters. Each installment is based on income actually received during the months leading up to that installment’s due date, then annualized to project a full-year liability.¹⁰

The first and second installments use the first three months of income. The third uses six months, the fourth uses nine. Each period’s income is projected to a full year, the applicable percentage is applied (25%, 50%, 75%, 100%), and prior installments already paid are credited.¹⁰ For each quarter you pay the lesser of the regular installment or the annualized installment, and any reduction is recaptured in later installments. You do not avoid tax; you shift its timing. At year-end, attach Form 2220 to Form 990-T to show the IRS how each installment was figured.

Payment Deadlines and How to Pay

Estimated tax installments are due on the 15th day of the 4th, 6th, 9th, and 12th months of the organization’s tax year. For a calendar-year organization, that means:

First installment: April 15
Second installment: June 15
Third installment: September 15
Fourth installment: December 15

Fiscal-year organizations follow the same pattern counting from the start of their own tax year. An organization on a July 1 fiscal year, for example, pays on October 15, December 15, March 15, and June 15. When a due date falls on a weekend or federal holiday, it moves to the next business day.

The IRS expects electronic payment for corporate estimated taxes through the Electronic Federal Tax Payment System (EFTPS), which is free and handles income, employment, estimated, and excise tax payments.¹¹ Payment is also available through an IRS business tax account or by direct pay. Form 990-W itself is never mailed; the payments arrive electronically and must land by the deadline regardless of when the worksheet is completed.

What Underpayment Costs

Missing an installment, or paying less than required, triggers an underpayment penalty figured on Form 2220. The penalty runs from the installment due date until the earlier of the actual payment date or the due date of the annual return. The IRS sets the interest rate quarterly based on the federal short-term rate; for the first quarter of 2026 the rate is 7%, dropping to 6% for the second quarter.¹²

No penalty applies if total tax for the year comes in under $500.¹³ You can also reduce or eliminate the penalty by showing that payments matched what the annualized income installment method or the adjusted seasonal installment method required. Both alternatives are calculated on Form 2220 and attached to Form 990-T.

Mistakes That Trip Organizations Up

Pooling all unrelated activities into a single UBTI number is the most frequent error. Siloing forbids using one activity’s loss to offset another’s income, and organizations that pool will understate tax and face penalties at filing.⁵

Confusing the $1,000 filing threshold with the $500 estimated tax threshold is another. Form 990-T must be filed when gross unrelated business income reaches $1,000, but estimated payments are only required when the actual tax liability reaches $500.⁴ An organization with $1,200 in gross unrelated business income may owe no tax after deductions and the $1,000 specific deduction, but still has to file.

Debt-financed income is easy to miss. Dividends from stock bought with borrowed funds, or rent from property acquired with a mortgage, can be swept into UBTI even though those income types are normally excluded. Review each investment for outstanding acquisition debt when estimating income.

Finally, mind the large-organization rule. If taxable income was over $1,000,000 in any of the prior three years, the prior-year safe harbor is gone after the first installment.⁹ Continuing to use last year’s tax as the benchmark for all four installments produces a penalty on installments two through four even when installment one was correct.

1
Internal Revenue Service. Estimated Tax: Unrelated Business Income
2
Office of the Law Revision Counsel. 26 U.S. Code 501 – Exemption From Tax on Corporations, Certain Trusts, Etc.
3
Internal Revenue Service. Instructions for Form 990-T (2025)
4
Internal Revenue Service. Unrelated Business Income Tax
5
Office of the Law Revision Counsel. 26 USC 512 – Unrelated Business Taxable Income
6
Office of the Law Revision Counsel. 26 U.S. Code 172 – Net Operating Loss Deduction
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U.S. Government Publishing Office. 26 U.S.C. 511 – Imposition of Tax on Unrelated Business Income of Charitable, Etc., Organizations
8
Internal Revenue Service. Unrelated Business Income Tax Returns
9
Office of the Law Revision Counsel. 26 U.S. Code 6655 – Failure by Corporation to Pay Estimated Income Tax
10
eCFR. 26 CFR 1.6655-2 – Annualized Income Installment Method
11
Internal Revenue Service. EFTPS: The Electronic Federal Tax Payment System
12
Internal Revenue Service. Quarterly Interest Rates
13
Internal Revenue Service. Instructions for Form 2220