Deferred Taxes and Book vs Cash

The core problem

When a company files its tax return, it follows tax rules set by the government. When it publishes its financial statements, it follows book rules (GAAP or IFRS). These two sets of rules often disagree on when revenue is recognised or when an expense is deductible.

The result: the tax expense on the Income Statement (book taxes) rarely matches the actual cash taxes paid to the government. The gap between the two creates deferred tax assets and deferred tax liabilities on the Balance Sheet.

Understanding this is essential for IB interviews because it shows up in:

• Walk-me-through-the-statements scenarios
• DCF analysis (deferred taxes affect true cash flow)
• M&A (purchase price allocation creates new deferred tax items)
• LBO modelling (tax shields from leverage)

---

Book taxes vs cash taxes

	Book taxes (Income Statement)	Cash taxes (paid to government)
What it follows	GAAP / IFRS	Tax code (HMRC / IRS)
Where it shows up	"Income Tax Provision" on the IS	Actual payment, visible in CFS or tax return
Purpose	Match tax expense to the period's revenue	Minimise current cash tax bill legally

The Income Tax Provision on the IS can be split into two components:

$$\text{Income Tax Provision} = \text{Current Tax Expense} + \text{Deferred Tax Expense}$$

• Current Tax Expense ≈ what you actually pay in cash this period
• Deferred Tax Expense ≈ the portion you'll pay (or save) in the future

---

Deferred Tax Liabilities (DTL)

A DTL arises when you pay less tax now than your book tax expense. You're deferring the payment to the future.

The most common cause: accelerated depreciation.

For book purposes, a company might depreciate a $100 machine over 10 years (straight-line, $10/year). For tax purposes, the government lets the company depreciate it faster — say $25 in Year 1.

	Book	Tax return
Depreciation Year 1	$10	$25
Taxable income (lower = less tax)	Higher	Lower
Tax paid	Higher on paper	Lower in cash

The company reports a higher tax expense on its Income Statement than it actually pays. The difference sits on the Balance Sheet as a Deferred Tax Liability — tax you owe the government in the future.

On the statements:

• IS: Tax expense reflects the full book rate
• CFS: DTL increase is added back (source of cash) because you paid less cash than the IS shows
• BS: DTL ↑ (long-term liability)

---

Deferred Tax Assets (DTA)

A DTA arises when you pay more tax now than your book tax expense. The government owes you a tax benefit in the future.

Common causes:

• Net Operating Losses (NOLs): The company lost money in prior years. Tax rules let you carry those losses forward to offset future taxable income, reducing future cash taxes.
• Bad debt reserves: The company writes off receivables for book purposes before the tax code allows the deduction.
• Accrued expenses: Certain liabilities (like warranty reserves) are deductible for book purposes before they're deductible for tax purposes.

On the statements:

• IS: Tax expense may be higher than what the company actually owes long-term
• CFS: DTA increase is subtracted (use of cash) because the company paid more in cash than the IS implies
• BS: DTA ↑ (long-term asset — it represents future tax savings)

---

How deferred taxes flow through all three statements

This is where most students get lost, so we'll do it slowly with numbers.

Worked example — a DTL from accelerated depreciation

The setup. In Year 1, a company buys a £100 machine.

• Book depreciation: £10 per year for 10 years (straight-line)
• Tax depreciation: £25 in Year 1 (the tax code lets you expense it faster)
• Pre-tax book income (before depreciation): £50
• Tax rate: 40%

The company has one set of numbers it reports to shareholders (book) and one set it files with HMRC (tax). They disagree on how much the depreciation expense is this year. Let's trace both.

Step 1 — What the tax return says. Taxable income = £50 − £25 tax depreciation = £25 Cash taxes owed = £25 × 40% = £10 paid to HMRC

Step 2 — What the Income Statement says. Pre-tax book income = £50 − £10 book depreciation = £40 Book tax expense (shown on IS) = £40 × 40% = £16 Net Income = £40 − £16 = £24

Step 3 — The mismatch. The IS shows £16 of tax expense, but the company only paid £10 in cash. The extra £6 isn't missing — it's owed to HMRC in the future (because tax depreciation ran out early; book depreciation will keep running). That £6 sits on the balance sheet as a Deferred Tax Liability.

The £6 splits the IS tax expense into two components:

• Current tax expense (what was paid this year): £10
• Deferred tax expense (what's owed later): £6

Step 4 — Now walk all three statements for Year 1.

Income Statement:

• Revenue/costs net of depreciation: +£40 pre-tax income
• Tax expense: −£16 (£10 current + £6 deferred)
• Net Income: +£24

Cash Flow Statement:

• Net Income: +£24
• Add back book depreciation (non-cash): +£10
• Add back increase in DTL (non-cash — the £6 wasn't actually paid): +£6
• Net change in cash: +£40

Notice the £40 of net cash matches the cash arithmetic from the tax return: £50 pre-dep income − £10 cash taxes = £40. ✓

Balance Sheet (year-end deltas):

• Cash: +£40
• PP&E: −£10 (book depreciation reduced it)
• Total Assets: +£30
• DTL: +£6 (new liability)
• Retained Earnings: +£24 (from Net Income)
• Total L + E: +£30 ✓

Balance Sheet balances. The DTL is the plug that makes the £6 gap between IS tax and cash tax reconcile.

The mirror image — a DTA

Now flip the story. Same company, same £50 pre-tax income, but this year it recorded a £15 bad-debt reserve that book rules allow as an expense but the tax code doesn't let it deduct until the debt is actually written off.

• Book pre-tax income = £50 − £15 = £35 → Book tax = £14 → Net Income = £21
• Tax return income = £50 (no bad-debt deduction yet) → Cash tax = £50 × 40% = £20 paid to HMRC

The company paid £20 in cash but only reports £14 of tax expense. The £6 gap is a future tax benefit — a Deferred Tax Asset.

CFS: Start from Net Income £21, add the £6 DTA increase as a use of cash (because real cash out was higher than IS tax). BS: Cash down by the extra £6, DTA up by £6. The two offset — balance sheet still balances.

---

The interview questions you'll get

"What's the difference between a deferred tax asset and a deferred tax liability?"

A DTA means the company has paid more tax in cash than what shows on its Income Statement — it has a future tax benefit. A DTL means the company has paid less tax in cash than what shows on its Income Statement — it has a future tax obligation. The most common cause of DTLs is accelerated depreciation for tax purposes, and the most common cause of DTAs is net operating loss carryforwards.

"How do deferred taxes affect the cash flow statement?"

An increase in the Deferred Tax Liability is added back on the CFS (source of cash) because the company's actual cash tax payment was lower than the Income Statement tax expense. An increase in the Deferred Tax Asset is subtracted on the CFS (use of cash) because the company paid more in cash taxes than shown on the IS.

"A company has a net operating loss of $100. How does this affect the statements going forward?"

The NOL creates a Deferred Tax Asset of $100 × the tax rate. In future profitable years, the company uses the NOL to reduce its taxable income, so it pays less cash in taxes. The DTA decreases as the NOL is used up, and the company's cash flow benefits from the tax savings.

---

Why this matters beyond accounting interviews

Deferred taxes come back in every advanced topic:

• DCF: When projecting free cash flow, you need to estimate cash taxes, not book taxes. If a company has large NOLs, its cash tax rate could be near zero for years.
• M&A: Purchase price allocation often creates new intangible assets that are amortised for book but not tax purposes (or vice versa), creating new deferred tax items.
• LBO: The interest tax shield from leverage reduces cash taxes, and sponsors actively plan around the tax impact of debt structures.

Get comfortable with the concept here and it'll pay dividends (pun intended) in every later topic.