Deferred Tax Assets vs Liabilities: Temporary vs Permanent Differences
Book income and taxable income rarely match. Some differences reverse over time (temporary, creating deferred tax assets or liabilities) and some do not (permanent). Here is exactly how each works, with three worked examples and the journal entries.
Book income and taxable income rarely match. Some differences reverse over time (temporary, creating deferred tax assets or liabilities) and some do not (permanent). Here is exactly how each works, with three worked examples and the journal entries.
Learning Objectives
- ✓Distinguish temporary differences (DTA/DTL) from permanent differences (no deferred effect).
- ✓Compute the deferred tax balance from a temporary difference and the enacted future rate.
- ✓Write the income tax provision journal entry across current and deferred components.
1. Direct Answer: Why Book and Tax Diverge
Book income (per GAAP) and taxable income (per the tax code) follow different rules, so reported income tax expense and actual taxes paid almost never match. Differences come in two flavors. TEMPORARY differences will reverse in future periods — depreciation method choices, revenue recognition timing, warranty accruals, prepaid expenses. They create deferred tax liabilities (DTL) when book income > taxable income in the current period (you will pay later), and deferred tax assets (DTA) when book income < taxable income (you have prepaid taxes effectively). PERMANENT differences never reverse — tax-exempt municipal-bond interest income, fines and penalties, certain meal expenses, life-insurance premiums where the company is the beneficiary. Permanent differences change income tax expense in the period they occur but do NOT create deferred balances. The reporting framework that puts these into the financial statements is ASC 740 (formerly FAS 109).
Key Points
- •Temporary differences reverse → create DTA or DTL.
- •Permanent differences never reverse → no deferred balance.
- •ASC 740 governs the framework; effective tax rate reconciliation shows both effects.
2. Temporary Differences: DTL Mechanics
A deferred tax liability arises when current-period book income exceeds taxable income — the entity has reported income now but will pay tax on it later. The classic example: accelerated tax depreciation (MACRS) creates higher tax deductions and lower taxable income early in an asset’s life relative to slower book depreciation; the timing reverses in later years when book depreciation continues but MACRS has already exhausted. To compute the DTL: (cumulative tax depreciation − cumulative book depreciation) × enacted future statutory tax rate. Journal: Debit Income Tax Expense (deferred portion); Credit Deferred Tax Liability. The DTL grows in early years and unwinds as the temporary difference reverses. Total tax expense across the life equals the cash tax paid; only the timing differs.
Key Points
- •DTL forms when book income > taxable income (book recognizes faster than tax).
- •DTL = (book basis − tax basis) × enacted future rate, when book basis > tax basis on liabilities OR < on assets.
- •Reverses over time as the underlying temporary difference reverses.
3. Temporary Differences: DTA Mechanics
A deferred tax asset arises when current-period book income is LESS than taxable income — the entity has effectively prepaid taxes that will offset future tax bills. The classic example: warranty accruals. Under GAAP, warranty expense is accrued when revenue is recognized; for tax, warranty costs deduct only when paid. So book warranty expense > tax warranty deduction in year 1, creating taxable income > book income and a DTA. Journal: Debit Deferred Tax Asset; Credit Income Tax Expense (deferred portion). DTAs also arise from net operating loss carryforwards, allowance for doubtful accounts, deferred compensation, and inventory reserves. The DTA must be tested for REALIZABILITY — if it is more likely than not that some or all will not be realized (because future taxable income is doubtful), a valuation allowance reduces the DTA. Loss-making startups with growing DTAs but no path to taxable income usually carry valuation allowances against most of the DTA.
Key Points
- •DTA forms when book income < taxable income (book recognizes slower than tax).
- •Examples: warranty accruals, NOL carryforwards, bad debt allowances, deferred comp.
- •Valuation allowance required if more-likely-than-not the DTA will not be realized.
4. Worked Example 1: Depreciation Difference (DTL)
A $50,000 asset, 5-year life, no salvage. Book uses straight-line: $10,000/year. Tax uses MACRS (5-year, half-year): 20.00%, 32.00%, 19.20%, 11.52%, 11.52%, 5.76%. Year 1 tax depreciation = $10,000 (50,000 × 20%); same as book. Year 2 tax depreciation = $16,000 vs book $10,000; difference $6,000. Cumulative through year 2: tax = $26,000, book = $20,000, temporary diff = $6,000. Enacted future tax rate 21%. DTL at end of year 2 = $6,000 × 21% = $1,260. Year 1 journal (no diff yet): Dr Income Tax Expense (current) for current tax due, no deferred entry. End of year 2 journal: Dr Income Tax Expense — Deferred $1,260; Cr Deferred Tax Liability $1,260. The DTL grows through years 2–3 and reverses in years 4–5 when book continues at $10,000 but MACRS slows to $5,760 and $2,880 in year 6.
Key Points
- •Different methods create cumulative book-tax timing differences.
- •DTL = cumulative temporary diff × enacted future rate.
- •DTL reverses naturally as the underlying difference reverses.
5. Worked Example 2: Warranty Accrual (DTA)
Company sells products with a 2-year warranty and accrues $40,000 in year 1 based on 2% of $2M sales. Actual warranty claims paid in year 1 = $5,000; year 2 = $30,000; year 3 = $5,000. Year 1 book warranty expense = $40,000 (the accrual); year 1 tax deduction = $5,000 (only paid claims). Temporary difference: $35,000. Tax rate 21%. DTA = $35,000 × 21% = $7,350. Journal year 1: Dr Deferred Tax Asset $7,350; Cr Income Tax Expense — Deferred $7,350. In year 2 the company pays $30,000 in warranty claims but accrues no new expense; the tax deduction of $30,000 exceeds the zero new book expense. The temporary difference reverses by $30,000, dropping DTA by $30,000 × 21% = $6,300. Final year 3 payment of $5,000 reverses the remaining DTA.
Key Points
- •Warranty accruals are a textbook DTA generator.
- •DTA grows when book expense > tax deduction; reverses as payments occur.
- •Total tax across the life is unchanged — only timing differs.
6. Worked Example 3: Permanent Difference (Tax-Exempt Interest)
A company earns $20,000 in municipal-bond interest (tax-exempt) and $100,000 in other taxable income. Statutory tax rate 21%. Book pre-tax income = $120,000. Taxable income = $100,000 (municipal interest excluded permanently). Current tax = $100,000 × 21% = $21,000. There is NO deferred tax effect — the municipal interest will never become taxable. Effective tax rate = $21,000 / $120,000 = 17.5%, below the statutory 21%. Effective tax rate reconciliation: Statutory tax (21% × $120,000) = $25,200; less municipal interest benefit ($20,000 × 21%) = ($4,200); ETR-applied total = $21,000. The reconciliation is required disclosure under ASC 740 and helps users see how permanent differences widen or narrow the effective rate.
Key Points
- •Tax-exempt interest is a permanent difference — no deferred entry.
- •Effective tax rate diverges from statutory through permanent differences.
- •ASC 740 requires effective rate reconciliation disclosure.
7. Income Tax Provision Journal Entry
The full income tax provision entry combines current and deferred components. Example: Year 1 tax payable $50,000 (from current taxable income × rate); DTL increase $1,260 (depreciation timing); DTA increase $7,350 (warranty accrual). Journal: Debit Income Tax Expense (current) $50,000; Debit Income Tax Expense (deferred) $1,260; Debit Deferred Tax Asset $7,350; Credit Deferred Tax Liability $1,260; Credit Income Taxes Payable $50,000; Credit Income Tax Expense (deferred) $7,350. Net Income Tax Expense on the income statement = $50,000 + $1,260 − $7,350 = $43,910. The net effect of the DTA offsets some of the current period’s expense because future tax savings have been recognized today.
Key Points
- •Total tax expense = current + deferred (DTL component) − deferred (DTA component).
- •Income Taxes Payable is the cash-due portion; deferred items go to deferred balance accounts.
- •Recognize DTAs and DTLs at the enacted future statutory rate.
8. Running a Provision in AccountingIQ
Provide book pre-tax income, the schedule of temporary and permanent differences, and the enacted statutory rate, and AccountingIQ produces the full provision: current tax, deferred tax, ending DTA and DTL balances, and the effective rate reconciliation. It flags items requiring a valuation allowance based on a more-likely-than-not threshold and the underlying realizability evidence. This content is for educational purposes only.
Key Points
- •Current + deferred provision with full journal entry.
- •Effective tax rate reconciliation prepared automatically.
- •Valuation-allowance prompts for realizability concerns.
High-Yield Facts
- ★Temporary differences reverse → DTA/DTL; permanent differences do not → no deferred effect.
- ★DTL = cumulative book-tax timing diff × enacted future rate (when book > tax basis on liabilities OR < on assets).
- ★DTAs need valuation allowance if realization is not more likely than not.
- ★Effective tax rate reconciliation reveals permanent differences.
- ★ASC 740 governs the framework; deferred balances use enacted, not current, rates.
Practice Questions
1. Book depreciation $10,000; tax depreciation $16,000; tax rate 21%. DTA or DTL, and amount?
2. A municipal-bond portfolio earns $10,000 of tax-exempt interest. What deferred tax entry?
3. Why might a startup with $50,000 in DTAs from NOL carryforwards record a full valuation allowance?
FAQs
Common questions about this topic
The ENACTED tax rate expected to apply in the period the temporary difference reverses. If a rate change is enacted but not yet effective, you use the future rate for differences that will reverse after the effective date. When a rate change is enacted in the period (e.g., the Tax Cuts and Jobs Act enacted in December 2017), all existing DTAs and DTLs are re-measured at the new rate, with the effect flowing through deferred tax expense.
ASC 740 requires a more-likely-than-not threshold (greater than 50% probability). Management assesses positive evidence (history of profitability, taxable income forecasts, reversing DTLs that will absorb DTAs) against negative evidence (history of losses, expiring carryforwards, lack of taxable income forecasts). If negative evidence outweighs positive, a valuation allowance reduces the DTA. The assessment is updated every reporting period.
Yes. Separate DTA/DTL balances are computed for federal and each state using the respective enacted rates. The state deferred tax effect on the federal return (the state tax deduction reducing federal taxable income) is also embedded in the calculation. For simplification many companies use a blended state-federal rate, but the technical answer is separate computation.
A net operating loss can be carried forward to offset future taxable income (20 years for losses generated before 2018, indefinitely with an 80%-of-taxable-income limit for losses generated 2018 onward in the U.S.). The benefit is recognized today as a DTA = NOL × enacted future rate, subject to valuation allowance assessment. If a company has a $1M NOL and the future rate is 21%, the DTA is $210,000 — but only if realization is more likely than not.
Yes. Provide the temporary and permanent differences (depreciation, warranties, NOLs, accruals, etc.) and the enacted future rate, and AccountingIQ produces the period’s current tax expense, deferred tax expense, ending DTA and DTL balances, valuation allowance flags, and the effective rate reconciliation. This content is for educational purposes only.