Under ASC 740-270, the interim tax provision is calculated by estimating an annual effective tax rate (AETR), applying it to year-to-date ordinary income from continuing operations, and then subtracting the tax already recognized in earlier quarters of the same fiscal year. Items that do not scale with annual ordinary income — tax law changes, share-based payment windfalls, uncertain tax position adjustments, and similar events — are treated as discrete and booked in full in the quarter they occur. The ASC 740-270 interim tax provision is therefore two calculations running in parallel: a rate-driven provision on ordinary results, and a separate discrete calculation on everything else.
Each quarter is treated as an integral part of the annual period, not a standalone measurement window. That framing is what makes the cumulative method work and what causes quarterly provisions to occasionally look strange in isolation.
Calculating the Estimated Annual Effective Tax Rate
The AETR is projected total annual tax expense divided by projected total annual ordinary income from continuing operations before tax.
The Numerator
Start with the federal corporate rate applied to projected taxable ordinary income, then layer in state and local taxes, foreign tax rates weighted by jurisdiction, permanent differences, and anticipated tax credits. Permanent differences such as non-deductible expenses or tax-exempt interest affect the tax computation without generating deferred taxes, so they flow directly into the rate estimate.1Deloitte Accounting Research Tool. ASC 740-10 – Objectives of ASC 740
Recurring credits such as the research and development credit go into the numerator only to the extent they are expected to reduce the projected annual tax liability. Credits expected to be carried forward or refunded rather than absorbed in the current year are handled differently. The estimated AETR must also reflect anticipated investment tax credits, foreign tax rates, percentage depletion, capital gains rates, and other available tax-planning alternatives.2Deloitte Accounting Research Tool. Deloitte’s Roadmap – Income Taxes – Chapter 7 – 7.1 Overview
The Denominator
The denominator is projected annual ordinary income or loss from continuing operations before income taxes. “Ordinary” is the key word. Unusual or infrequent items, items reported net of tax, and anything else receiving discrete treatment are stripped out and their tax computed separately.
What Must Be Excluded From the AETR
ASC 740-270-30-11 and 30-12 require excluding the following from the AETR computation:3Deloitte Accounting Research Tool. Deloitte’s Roadmap – Income Taxes – Chapter 7 – 7.2 Items Accounted for Separately From the AETR
- Effects of newly enacted tax laws or rate changes on deferred tax balances and prior-year taxes
- Changes in judgment about beginning-of-year valuation allowances
- Tax effects from share-based payment awards when the tax deduction differs from cumulative book compensation cost
- Significant items reported separately or net of their related tax effect
- Any component of ordinary income, or its related tax, that the entity cannot reliably estimate
Each of these gets discrete treatment: the full tax effect is recognized in the quarter the item occurs.
Updating the Rate
The AETR is not fixed at Q1. At the end of each successive interim period, management revises it to reflect the best current estimate for the year.4EY. Income Taxes – Financial Reporting Developments A shift in the domestic-to-foreign income mix, a revised revenue projection, or a change in expected permanent differences can all move the rate. The updated rate is applied cumulatively to year-to-date income.
Applying the Rate: The Cumulative Catch-Up Method
The mechanic has three steps:
- Multiply year-to-date ordinary income before tax by the current AETR.
- Subtract cumulative tax expense or benefit already recognized in prior interim periods of the current fiscal year.
- The difference is the current quarter’s provision.
The method is self-correcting. If Q1 was booked at a 24% AETR and Q2 data pushes the estimate to 26%, the Q2 provision does not simply apply 26% to Q2 income. It applies 26% to all year-to-date income and then backs out what was already booked in Q1. The current quarter absorbs the entire adjustment, which can produce a Q2 provision that looks disproportionately large or small relative to Q2 pretax income. That is the mechanism working, not a mistake.
ASC 740-270-25-2 puts the principle plainly: tax on ordinary income is computed at the estimated annual effective tax rate, and tax on everything else is individually computed and recognized when the item occurs.3Deloitte Accounting Research Tool. Deloitte’s Roadmap – Income Taxes – Chapter 7 – 7.2 Items Accounted for Separately From the AETR
Discrete Tax Items
Discrete items sit outside the AETR. Their full tax effect is recognized in the quarter they occur because they are not driven by the level of annual ordinary income, and blending them into the rate would distort every other quarter.
Tax Law Changes
When legislation changes rates or provisions, the entire effect on existing deferred tax assets and liabilities is recognized in the quarter of enactment, even if the effective date is in a future period. Deferred tax balances are re-measured at the new rate, and the resulting gain or loss hits income tax expense from continuing operations in that quarter. The AETR is then updated going forward to incorporate the new rate for the remaining quarters.5Deloitte Accounting Research Tool. Deloitte’s Roadmap – Income Taxes – Chapter 7 – 7.5 Other Considerations
Uncertain Tax Positions
Recognition or measurement changes for uncertain tax positions are discrete. A benefit is recognized only when it is more likely than not that the position will be sustained on examination.6Deloitte Accounting Research Tool. Deloitte’s Roadmap – Income Taxes – Chapter 4 – 4.5 Subsequent Changes in Recognition and Measurement Once recognized, it is measured at the largest amount greater than 50% likely to be realized on settlement.7Deloitte Accounting Research Tool. Deloitte’s Roadmap – Income Taxes – Chapter 4 – 4.3 Measurement When the assessment changes, or when a statute of limitations expires and eliminates the exposure, the adjustment lands in the quarter of the change.
Stock-Based Compensation
Following ASU 2016-09, excess tax benefits and tax deficiencies from stock-based compensation are discrete in the period they occur.8Deloitte Accounting Research Tool. Frequently Asked Questions About ASU 2016-09 These arise whenever the tax deduction on an award differs from the cumulative compensation cost recognized in the financial statements. When a large block of options is exercised or a significant restricted stock tranche vests in a single quarter, the swing can be material.
Valuation Allowance Changes From Discrete Events
A valuation allowance change caused by a discrete event is itself discrete. If new legislation extends the carryforward period for net operating losses and a previously unrealizable deferred tax asset becomes realizable, the release is recorded entirely in the quarter of the law change. A valuation allowance change driven purely by a shift in projected annual ordinary income runs through the AETR instead and is applied cumulatively.
Interim Losses
Interim losses are where judgment gets tested. A tax benefit for an interim ordinary loss is recognized only if the benefit is expected to be realized during the year, by offsetting income in later quarters, or is recognizable as a deferred tax asset at year-end.3Deloitte Accounting Research Tool. Deloitte’s Roadmap – Income Taxes – Chapter 7 – 7.2 Items Accounted for Separately From the AETR If neither condition holds, the benefit is limited or eliminated.
When management projects a full-year ordinary loss, the analysis moves to whether the resulting net operating loss carryforward will be realizable, which depends on the four sources of taxable income described below. The benefit is recognized only to the extent it is more likely than not the carryforward will produce future value.
Any benefit recognized for an interim loss can be reversed. If projections shift in a later quarter and the annual carryforward looks less realizable, the previously recognized benefit must be unwound. That is a feature of the integral view, not an anomaly.
Loss Jurisdictions Excluded From the Worldwide Rate
When a company anticipates an ordinary loss in a jurisdiction for which no tax benefit can be recognized, that jurisdiction’s income and related tax must be excluded from the worldwide AETR. A separate rate is computed and applied independently for that jurisdiction.3Deloitte Accounting Research Tool. Deloitte’s Roadmap – Income Taxes – Chapter 7 – 7.2 Items Accounted for Separately From the AETR Without the exclusion, the loss jurisdiction would drag down the blended rate and distort the provision for every profitable jurisdiction.
Valuation Allowances at Interim
The valuation allowance assessment must be performed each interim period based on the full-year projection, not just the current quarter’s results.
The Four Sources of Taxable Income
Whether a deferred tax asset will be realized depends on whether sufficient taxable income will exist in the right periods. ASC 740-10-30-18 identifies four potential sources:9Deloitte Accounting Research Tool. Deloitte’s Roadmap – Income Taxes – Chapter 5 – 5.3 Sources of Taxable Income
- Reversal of existing taxable temporary differences, which generate taxable income as deferred tax liabilities unwind
- Future taxable income exclusive of reversing temporary differences and carryforwards
- Carryback to prior years where permitted under current law
- Tax-planning strategies the entity would take if necessary, such as accelerating taxable income to use expiring carryforwards or changing the character of income from ordinary to capital
Each source is evaluated on a full-year basis every interim period. The valuation allowance covers whatever portion of the deferred tax asset is not supported by these sources under the more-likely-than-not standard.
Cumulative Losses as Negative Evidence
A cumulative loss in recent years is among the strongest pieces of negative evidence against realizing deferred tax assets. The codification does not set a bright-line period, but a three-year cumulative pretax loss (current year plus two prior years) is generally treated as significant negative evidence that is difficult to overcome.10Deloitte Accounting Research Tool. Deloitte’s Roadmap – Income Taxes – Chapter 5 – 5.2 Basic Principles of Valuation Allowances Overcoming it requires substantial positive evidence that is objectively verifiable, such as executed contracts, firm backlog, or binding sale agreements. Management projections alone rarely suffice.
Routing the Change Through the Provision
The routing matters. A valuation allowance change driven by a revised projection of annual ordinary income flows through the AETR and is applied cumulatively. A change driven by a discrete event, such as new legislation altering carryforward rules, is recognized in full in the quarter of the event. Misclassifying one for the other can materially misstate the quarter.
When the AETR Cannot Be Reliably Estimated
Some entities cannot produce a reliable annual rate. Startups, turnarounds, and companies operating near breakeven often find that small changes in projected income cause enormous swings in the AETR. ASC 740-270-25-3 addresses this: if the entity cannot estimate a part of its ordinary income or the related tax but can otherwise make a reliable estimate, the tax on the non-estimable item is reported discretely in the period it occurs.3Deloitte Accounting Research Tool. Deloitte’s Roadmap – Income Taxes – Chapter 7 – 7.2 Items Accounted for Separately From the AETR
This exception most often applies to individual foreign jurisdictions with unreliable projections. That jurisdiction’s ordinary income and related tax are excluded from the worldwide AETR, and the tax is reported discretely as results become known. The remaining jurisdictions continue on the standard methodology.
Multinational Considerations and GILTI
For multinationals, the AETR is a weighted blend of every jurisdiction in which the company earns income, reflecting anticipated foreign tax rates and foreign tax credit utilization. Because the jurisdictional income mix can shift meaningfully during the year, quarterly AETR revisions tend to be more frequent for global companies than for purely domestic ones.
Global Intangible Low-Taxed Income adds a further layer. For taxable years of foreign corporations beginning after December 31, 2025, the 2025 Act requires a taxpayer to include its net CFC tested income (rather than GILTI as previously computed) in the AETR estimate.3Deloitte Accounting Research Tool. Deloitte’s Roadmap – Income Taxes – Chapter 7 – 7.2 Items Accounted for Separately From the AETR
A recurring issue arises when a foreign subsidiary generates losses that cannot support a benefit in its own jurisdiction but do reduce the parent’s U.S. GILTI inclusion. Two approaches are acceptable in practice: include both the foreign loss and the corresponding U.S. benefit in the worldwide AETR, or exclude the foreign loss while including the U.S. benefit. Whichever approach is chosen should be applied consistently.
Tax Law Enactment Versus Change in Estimate
Changes to the AETR from revised projections are prospective, using the cumulative catch-up method. Prior quarters are not restated because the running total corrects itself.
Newly enacted tax law is different. The full effect is a discrete item in the quarter of enactment, including the re-measurement of existing deferred tax assets and liabilities at the new rate, with the adjustment booked to tax expense from continuing operations.5Deloitte Accounting Research Tool. Deloitte’s Roadmap – Income Taxes – Chapter 7 – 7.5 Other Considerations The AETR is then rebuilt going forward at the new rate.
Changes in judgment about the realizability of deferred tax assets, such as adopting a new tax-planning strategy, follow the change-in-estimate framework and are recognized in the quarter judgment changes: through the AETR if driven by revised income projections, or discretely if driven by a non-income event.
The Fourth Quarter
The fourth quarter uses the same mechanic. Management estimates the AETR at year-end and applies it to full-year ordinary income; by that point the estimate is usually very close to actual. The Q4 provision is the residual: full-year tax expense minus what was recognized in Q1 through Q3.4EY. Income Taxes – Financial Reporting Developments
This is why Q4 provisions sometimes look odd on the surface. Earlier-quarter overestimates produce an unusually low Q4 provision, or even a benefit. Earlier-quarter underestimates leave Q4 to absorb the shortfall. Q4 is not independently meaningful. It reads correctly only in the context of the full-year cumulative provision.