GAAP vs. IFRS: Key Differences Every CPA Candidate Must Know

Why GAAP vs. IFRS Matters on the CPA Exam

The CPA exam, particularly the FAR section, tests candidates on both U.S. Generally Accepted Accounting Principles (GAAP) and International Financial Reporting Standards (IFRS). While the two frameworks share a common goal of producing transparent, comparable financial statements, they diverge on several key points that examiners love to test. Understanding these differences is not just academic; as globalization increases, CPAs routinely encounter IFRS in multinational engagements, cross-border transactions, and SEC filings by foreign private issuers.

Conceptual Framework Differences

U.S. GAAP is a rules-based system maintained by the Financial Accounting Standards Board (FASB) through the Accounting Standards Codification (ASC). It provides detailed guidance with specific thresholds, bright-line tests, and extensive industry-specific rules. IFRS, maintained by the International Accounting Standards Board (IASB), follows a principles-based approach that emphasizes professional judgment over rigid rules. This fundamental philosophical difference underpins nearly every specific divergence between the two systems.

The FASB conceptual framework identifies the primary qualitative characteristics of useful financial information as relevance and faithful representation. IFRS shares these characteristics but historically placed greater emphasis on substance over form and the concept of prudence (conservatism), which was reintroduced in the revised IFRS Conceptual Framework in 2018.

Inventory Valuation

LIFO Prohibition Under IFRS

One of the most commonly tested differences involves inventory. U.S. GAAP permits Last-In, First-Out (LIFO), First-In, First-Out (FIFO), and weighted-average cost methods. IFRS under IAS 2 prohibits LIFO entirely. This has significant practical implications: a U.S. company using LIFO that wants to report under IFRS must restate its inventory to FIFO or weighted average.

Inventory Write-Down Reversals

Under U.S. GAAP, once inventory is written down to its lower of cost or net realizable value (NRV), the write-down establishes a new cost basis, and subsequent reversals are prohibited. Under IFRS, if the circumstances that caused the write-down no longer exist, the entity must reverse the write-down up to the original cost. For example, if inventory with a cost of $100,000 was written down to $70,000 under both frameworks, and NRV later recovers to $95,000, IFRS requires a $25,000 reversal while GAAP does not.

Revenue Recognition

ASC 606 and IFRS 15 are substantially converged standards for revenue recognition, both following the five-step model: identify the contract, identify performance obligations, determine the transaction price, allocate the transaction price, and recognize revenue when obligations are satisfied. However, minor differences remain in application guidance, particularly around licensing, principal-versus-agent considerations, and certain industry-specific areas that GAAP addresses but IFRS does not.

Property, Plant, and Equipment

Revaluation Model

U.S. GAAP requires the cost model for property, plant, and equipment (PP&E), meaning assets are carried at historical cost less accumulated depreciation and impairment losses. IFRS under IAS 16 permits an election between the cost model and the revaluation model, under which assets are carried at fair value at the date of revaluation less subsequent depreciation and impairment. When the revaluation model is chosen, it must be applied to the entire class of assets. Revaluation increases are credited to other comprehensive income (revaluation surplus), while decreases are recognized in profit or loss unless they reverse a previous increase.

Component Depreciation

IFRS requires component depreciation, where significant parts of an asset with different useful lives are depreciated separately. While GAAP permits component depreciation, it does not require it, and most U.S. companies depreciate the entire asset as a single unit.

Lease Accounting

ASC 842 and IFRS 16 both require lessees to recognize most leases on the balance sheet. However, GAAP classifies leases as either finance leases or operating leases for the lessee, affecting the income statement pattern. IFRS 16 treats virtually all lessee leases as a single type, similar to GAAP finance leases, recognizing depreciation on the right-of-use asset and interest on the lease liability. This means total expense under IFRS is front-loaded for all leases, while GAAP operating leases produce straight-line lease expense.

Financial Statement Presentation

GAAP requires a classified balance sheet separating current and noncurrent items. IFRS also generally requires current/noncurrent distinction but allows a liquidity-based presentation when it provides more relevant information (common for financial institutions). On the income statement, GAAP requires classification of expenses by function (cost of goods sold, selling expenses, administrative expenses), while IFRS allows classification by either function or nature (materials, salaries, depreciation). IFRS also prohibits the use of the term "extraordinary items," which GAAP eliminated as well under ASU 2015-01.

Impairment of Long-Lived Assets

Under GAAP (ASC 360), impairment of long-lived assets uses a two-step process: first, a recoverability test comparing the asset's carrying amount to the undiscounted future cash flows; second, if impairment exists, measuring the loss as the excess of carrying amount over fair value. IFRS (IAS 36) uses a one-step approach comparing carrying amount to recoverable amount, which is the higher of fair value less costs to sell and value in use (present value of future cash flows). Additionally, IFRS permits reversal of impairment losses for assets other than goodwill, while GAAP does not.

Key Exam Tips

• Focus on the differences that produce different numerical outcomes: inventory write-down reversals, revaluation model availability, and lease classification.
• Remember that LIFO is the single most distinctive GAAP-only method and is prohibited under IFRS.
• Both frameworks now share the same five-step revenue recognition model, so differences there are narrower than they once were.
• IFRS allows more reversals (inventory write-downs, asset impairments) while GAAP generally prohibits them.
• When in doubt, remember the overarching theme: GAAP is more prescriptive, IFRS allows more judgment.