Income Taxes

Learning Objectives

• Explain why deferred taxes exist using the two-system model
• Distinguish between temporary differences and permanent differences
• Calculate deferred tax assets and deferred tax liabilities under ASC 740
• Apply the valuation allowance to deferred tax assets
• Evaluate uncertain tax positions using the two-step framework
• Account for the effect of tax rate changes on deferred balances

The Core Idea: Two Systems, One Entity

Here is the single most important thing to understand about income tax accounting: GAAP and the tax code are two separate accounting systems tracking the same entity at the same time. Both systems record every transaction. Both require debits to equal credits. Both will, over the entity's entire lifetime, recognize the same total revenue, the same total expenses, and the same total income. But they use different rules for when they recognize those amounts.

Because the timing rules differ, the two systems show different numbers at any given moment. The deferred tax balance is the gap account — it tracks the cumulative divergence and represents the future tax consequence of that gap eventually closing.

That's it. That is deferred tax accounting. Everything else — DTAs, DTLs, valuation allowances, rate changes — is a consequence of this one structural reality.

Temporary vs. Permanent Differences

This is the most important classification in deferred taxes.

Temporary differences are timing differences — both systems will recognize the same total amount, just at different times. The gap opens and then closes. These create deferred tax assets or liabilities.

Permanent differences are recognition differences — one system recognizes an item that the other never will. The gap will never close. These affect only the current period's effective tax rate. They do not create deferred taxes.

Common Temporary Differences

Common Permanent Differences

• Municipal bond interest — GAAP recognizes as income; tax exempts it permanently
• Fines and penalties — GAAP recognizes as expense; tax disallows the deduction
• Life insurance premiums on officers — GAAP recognizes as expense; tax disallows when entity is beneficiary
• Meals expense (disallowed portion) — GAAP expenses in full; tax allows only partial deduction

Deferred Tax Assets and Liabilities

Deferred Tax Liability (DTL) — The entity has paid less tax than GAAP says it should have, so it owes the difference in the future. The GAAP books show higher income than the tax return. Most common cause: accelerated depreciation for tax.

Deferred Tax Asset (DTA) — The entity has paid more tax than GAAP says it should have, so it gets the benefit back in the future. The tax return shows higher income than the GAAP books. Common causes: warranty accruals, bad debt allowances, NOL carryforwards.

The Formula

Use the rate expected to be in effect when the difference reverses, not the current rate.

Worked Example

A company purchases equipment for $100,000. Book depreciation: straight-line over 5 years ($20,000/year). Tax depreciation: accelerated, $35,000 in Year 1. Tax rate: 25%.

Year 1:

• Temporary difference: $35,000 - $20,000 = $15,000
• Tax basis ($65,000) < Book basis ($80,000) — tax depreciated faster
• This creates a DTL: $15,000 x 25% = $3,750

Journal entry (deferred component only):

The full tax provision entry records both the current payable (from the tax return) and the deferred component. Together they equal total income tax expense — the complete economic tax cost for the period.

The Valuation Allowance

A DTA represents future tax savings. But those savings only materialize if the entity earns enough future taxable income to use them. If the entity is unprofitable and expects to stay that way, the DTA is worthless.

The valuation allowance writes the DTA down to the amount that is more likely than not (>50% probability) to be realized. It is a contra-asset.

Positive evidence (supports realization): strong earnings history, existing contracts, appreciated assets that could be sold to generate taxable income.

Negative evidence (supports allowance): cumulative losses in the three-year lookback period, history of unused carryforwards, unsettled circumstances. Negative evidence generally carries more weight.

Journal entry to establish:

The VA is reassessed each period. Increasing it raises tax expense. Decreasing it lowers tax expense. This is one of the highest-judgment areas in GAAP — management is forecasting future profitability, and that forecast directly moves the bottom line.

Uncertain Tax Positions

An uncertain tax position (UTP) is a position on a tax return where the entity is not certain the taxing authority will agree. ASC 740-10 uses a two-step framework:

Step 1 — Recognition: More-Likely-Than-Not

Is it more likely than not (>50%) that the position will be sustained on its technical merits? Assume the taxing authority examines it with full knowledge of all relevant information.

• Yes → proceed to Step 2
• No → no tax benefit recognized. Record the full amount as an unrecognized tax benefit liability

Step 2 — Measurement: Largest Amount

Measure the benefit at the largest amount with a greater than 50% cumulative likelihood of being realized upon settlement.

Example: A company takes a $100,000 deduction.

• 70% chance $80,000 is sustained
• 20% chance $60,000 is sustained
• 10% chance $0 is sustained

More-likely-than-not threshold is met (70% > 50%). The largest amount with >50% cumulative likelihood is $80,000. Recognize $80,000 benefit; record $20,000 as unrecognized tax benefit liability.

Interest and penalties on UTPs are recognized in either income tax expense or a separate line item — an accounting policy election that must be disclosed.

Effect of Tax Rate Changes

When the enacted tax rate changes, all existing DTAs and DTLs are remeasured at the new rate in the period of enactment:

• Rate decrease → DTLs shrink (benefit), DTAs shrink (expense)
• Rate increase → DTLs grow (expense), DTAs grow (benefit)
• The adjustment hits income tax expense in the enactment period — even if the rate takes effect in a future year

Example: DTL of $100,000 based on 25% rate (underlying temporary difference = $400,000). New enacted rate: 21%.

• New DTL: $400,000 x 21% = $84,000
• Adjustment: $100,000 - $84,000 = $16,000 benefit
• Entry: DR Deferred Tax Liability $16,000, CR Income Tax Expense $16,000

The gap between the two clocks hasn't changed — the same temporary differences exist. But the dollar value of the gap changed because the rate that will apply when it closes is now different.

Rate changes are recognized when enacted (signed into law), not when proposed or passed by one chamber. The full effect hits the enactment period.

Tax Rate Reconciliation

The effective tax rate (income tax expense / pre-tax book income) differs from the statutory rate (21% federal) because of permanent differences and discrete items:

Each row shows how the item pulls the effective rate away from statutory. Green rates reduce your tax cost; red rates increase it. The dollar column is just rate effect x pre-tax income — no new formulas, just multiplication.

Note that temporary differences do not appear in this reconciliation. They shift tax between periods but don't change the total tax cost relative to book income. Only permanent differences and discrete items create a persistent gap between statutory and effective rates.

Intraperiod Tax Allocation

ASC 740 requires income tax expense to be allocated across components of comprehensive income:

• Continuing operations — receives the computed tax expense
• Discontinued operations — reported net of its own tax effect
• Other comprehensive income — each OCI item reported net of its own tax effect
• Prior period adjustments — reported net of tax in retained earnings

This ensures each line item reflects its own tax impact.