Tax Depreciation vs Book Depreciation: Key Differences and How to Record Both

Why Depreciation Differs on Tax Returns vs. Financial Statements

Depreciation is one of the few areas where the amount reported on your tax return can differ significantly from the amount shown on your financial statements — and the IRS is perfectly fine with that. Tax depreciation follows the Internal Revenue Code (specifically MACRS under IRC §168), while book depreciation follows GAAP or IFRS standards. The result is a temporary difference that creates deferred tax assets or liabilities on your balance sheet.

Understanding both systems is essential for small business owners, controllers, and tax professionals. Getting it wrong can lead to overpaying taxes, misstating financial results, or triggering audit red flags. For foundational depreciation entries, see our guide on journal entries for depreciation.

Quick Answer: The Core Difference

Tax depreciation is calculated using the Modified Accelerated Cost Recovery System (MACRS), which allows faster write-offs in the early years of an asset's life. Book depreciation is typically calculated using the straight-line method, spreading the cost evenly over the useful life. The difference between the two creates a temporary timing difference that reverses over the asset's life.

Because tax depreciation is higher in early years, taxable income is lower than book income initially — creating a deferred tax liability. In later years, the relationship reverses.

How Tax Depreciation Works (MACRS)

The MACRS system, established by the Tax Reform Act of 1986, is the mandatory depreciation method for federal income tax purposes in the United States. Key features include:

• Recovery periods: Assets are assigned to specific class lives (3, 5, 7, 10, 15, 20, 27.5, or 39 years) based on the asset type.
• Conventions: The half-year convention assumes all assets are placed in service at mid-year; the mid-quarter convention applies if more than 40% of assets are placed in service in the last quarter.
• Depreciation methods: Most tangible personal property uses the 200% declining balance method (switching to straight-line when optimal), while residential rental property uses straight-line over 27.5 years and nonresidential real property uses straight-line over 39 years.
• Section 179 expensing: Allows immediate expensing of qualifying assets up to a threshold ($1,220,000 in 2025, subject to phase-outs). Our Section 179 deduction guide for small business covers this in detail.
• Bonus depreciation: Additional first-year depreciation percentage (60% for 2025, declining 20% per year through 2027).

Common MACRS Recovery Periods

Asset Type	Recovery Period	Method
Computers, office equipment	5 years	200% DB
Vehicles, light trucks	5 years	200% DB
Office furniture, fixtures	7 years	200% DB
Qualified improvement property	15 years	150% DB
Residential rental property	27.5 years	Straight-line
Nonresidential real property	39 years	Straight-line

How Book Depreciation Works (GAAP/IFRS)

Under GAAP and IFRS, the objective of depreciation is to allocate the cost of an asset systematically over its useful life in a manner that reflects the pattern of economic benefits consumed. The most common methods include:

Straight-Line Method

The simplest and most widely used method. Annual depreciation equals the depreciable cost (cost minus salvage value) divided by the useful life in years:

Annual Depreciation = (Cost − Salvage Value) ÷ Useful Life

Under IFRS, salvage value is referred to as "residual value," and the approach is functionally identical. This method is required for intangible assets with finite lives and is the default for most fixed assets.

Declining Balance Method

An accelerated method that applies a fixed percentage to the declining book value of the asset each year. Common multiples include 200% (double-declining balance) and 150%:

Annual Depreciation = Book Value at Beginning of Year × Depreciation Rate

This method produces higher depreciation in early years, but unlike MACRS, it considers salvage value (the asset is not depreciated below its residual value).

Units-of-Production Method

Depreciation is based on actual usage rather than time. This method is ideal for manufacturing equipment where wear is proportional to output:

Depreciation per Unit = (Cost − Salvage Value) ÷ Total Estimated Units

Annual Depreciation = Depreciation per Unit × Units Produced This Year

Journal Entries: Recording Both Depreciation Systems

When tax and book depreciation differ, your accounting records must track both. The book depreciation is recorded in the general ledger, and the difference is captured through deferred tax entries.

Step 1: Record Book Depreciation

This entry reflects the GAAP/IFRS-compliant depreciation on your financial statements.

Step 2: Calculate and Record Deferred Tax

The difference between tax depreciation and book depreciation creates a temporary difference. When tax depreciation exceeds book depreciation (the typical case in early years), you record a deferred tax liability:

The deferred tax liability represents the taxes that will be owed in future years when book depreciation exceeds tax depreciation (the reversal period). For a deeper treatment of these concepts, see our guide on deferred tax: temporary vs. permanent differences.

Numerical Example

Consider a manufacturing company that purchases a $100,000 piece of equipment classified as 7-year MACRS property. The company uses straight-line depreciation for book purposes with a 10-year useful life and no salvage value.

Year 1 Calculations

Book depreciation (straight-line): $100,000 ÷ 10 = $10,000

Tax depreciation (MACRS 200% DB, 7-year, half-year convention): $100,000 × 14.29% = $14,290

Temporary difference: $14,290 − $10,000 = $4,290 (tax depreciation exceeds book)

Deferred tax liability at 21%: $4,290 × 21% = $900.90

Assuming total pre-tax income of $50,000 and a 21% tax rate:

Year 8 Reversal

By Year 8, the MACRS depreciation is nearly complete (the 7-year property is fully depreciated), but book depreciation continues. Tax depreciation might be $0 while book depreciation remains $10,000. The temporary difference reverses:

Book depreciation: $10,000

Tax depreciation: $0

Reversing difference: $10,000 (book exceeds tax)

This reversal reduces the deferred tax liability and increases current taxes payable, as the timing difference unwinds.

IFRS Considerations

Under IFRS, component depreciation is required — each significant component of an asset with a different useful life must be depreciated separately. IFRS also permits a revaluation model for property, plant, and equipment, which can further complicate the book-to-tax comparison. Additionally, IFRS does not allow the LIFO inventory method, so companies reporting under both US GAAP and IFRS may have multiple book-to-tax differences beyond depreciation.

For more on the broader differences between reporting frameworks, see our article on what is deferred tax.

Common Mistakes to Avoid

• Using tax depreciation for financial statements: This understates net income and asset values, violating GAAP/IFRS requirements.
• Ignoring deferred tax entries: The difference between tax and book depreciation must be tracked as a deferred tax liability or asset. Omitting these entries misstates both the balance sheet and effective tax rate.
• Applying the wrong MACRS recovery period: Misclassifying assets (e.g., using 5-year instead of 7-year) can lead to incorrect tax deductions and potential penalties.
• Forgetting the half-year or mid-quarter convention: The applicable convention affects the first-year depreciation amount and must be applied consistently.
• Not reconciling book and tax depreciation schedules: Maintain a detailed schedule showing both calculations side by side for each asset, including differences and running deferred tax balances.

Key Takeaways

• Tax depreciation (MACRS) and book depreciation (GAAP/IFRS) serve different purposes and often produce different amounts.
• MACRS accelerates depreciation for tax purposes, reducing taxable income in early years compared to book income.
• The difference creates a deferred tax liability in early years that reverses when book depreciation exceeds tax depreciation.
• Record book depreciation in the general ledger and track the tax difference through deferred tax journal entries.
• Maintain separate depreciation schedules for tax and book to ensure compliance with both the IRS and accounting standards.
• Section 179 and bonus depreciation can create even larger book-to-tax differences in the first year of an asset's life.