IFRS vs US GAAP: Key Accounting Differences

What's the Difference Between IFRS and US GAAP?

IFRS (International Financial Reporting Standards) is the global accounting standard, used in over 140 jurisdictions. US GAAP (Generally Accepted Accounting Principles) is the accounting standard for US public companies, set by the FASB (Financial Accounting Standards Board).

Superficially they look similar — both define how to recognise revenue, account for leases, value assets, and calculate profit. But underneath, they differ in philosophy, measurement, and presentation. A transaction accounted for one way under IFRS might be accounted for differently under US GAAP, moving revenue, profit, and asset values around the balance sheet.

Philosophy: Principles-Based vs Rules-Based

The headline difference is philosophy:

• IFRS is principles-based. You are told the objective (e.g., "recognise revenue when control of goods passes to the customer"), then expected to apply judgment. The standard gives guidance, but the principle is supreme. This gives preparers flexibility but requires careful interpretation.
• US GAAP is rules-based. It often prescribes exactly what to do for a specific transaction type. There is less judgment required, but more prescriptive rules to memorise and apply.

In practice, both require professional judgment. But a principles-based approach means IFRS companies might reach different (but defensible) conclusions than US GAAP companies facing identical facts. Auditors challenge this regularly.

Revenue Recognition: IFRS 15 vs ASC 606

Here's the good news: IFRS 15 and ASC 606 are substantially converged. Both use the same five-step model:

1. Identify the contract with a customer
2. Identify performance obligations
3. Determine transaction price
4. Allocate price to obligations
5. Recognise revenue when (or as) obligation is satisfied

The core principle is identical: recognise revenue when (or as) control of goods or services transfers to the customer. Both standards define "control" the same way.

Where they differ:

• Contract modifications: IFRS 15 treats some modifications as new contracts; ASC 606 uses slightly different guidance, potentially recognising more as contract changes.
• Licensing: Software and licence-type arrangements have marginally different treatment.
• Transition: The transition guidance differed slightly; going forward, differences should narrow.

Reference: IFRS 15 paragraphs 1— 40; ASC 606-10-1 onwards.

More details on revenue recognition →

Lease Accounting: IFRS 16 vs ASC 842

Again, good news: IFRS 16 and ASC 842 are substantially aligned. Both require lessees to recognise:

• A right-of-use (ROU) asset
• A lease liability

Both abolished the operating lease / finance lease distinction for lessees. The measurement is nearly identical.

Where they differ:

• Initial measurement: ASC 842 permits a practical expedient to measure the ROU asset at the lease liability amount, whereas IFRS 16 requires adding initial direct costs and restoration obligations (though the net effect is often similar).
• Reassessment: IFRS 16 requires reassessment when certain conditions change (e.g., extension options become likely); ASC 842 has slightly different triggers.
• Lessor accounting: Some differences in how lessors recognise income, but this rarely affects consolidated financial statements.

For most leases, the balance sheet impact is nearly identical. Auditors hunt for edge cases where the detail matters.

Reference: IFRS 16 paragraphs 1— 4; ASC 842-10-1 onwards.

More details on lease accounting →

Goodwill Impairment

Here's a material difference: IFRS and US GAAP test goodwill impairment in different ways.

IFRS: One-Step Test

Compare the carrying amount to the recoverable amount (the higher of fair value less costs to sell, and value-in-use). If carrying exceeds recoverable, impair the difference.

US GAAP: Two-Step Test

Step 1: Compare fair value (of the reporting unit) to carrying amount (including goodwill). If fair value exceeds carrying, no impairment.

Step 2: If fair value is less than carrying, calculate the implied fair value of goodwill by subtracting the fair values of identified net assets from the fair value of the reporting unit. If the carrying amount of goodwill exceeds this implied amount, impair the difference.

Practical impact: IFRS often produces a lower impairment (because value-in-use is based on internal cash flow projections, not market fair value). US GAAP is stricter, using fair value directly. In down markets, US GAAP goodwill write-downs can be larger.

Reference: IFRS 36 paragraphs 1— 42; ASC 350-20-1 onwards.

More details on goodwill impairment →

Inventory Valuation

Both standards require inventory to be valued at the lower of cost and net realisable value (IFRS) or lower of cost and market (US GAAP). These sound identical but have a subtle difference:

The US GAAP "market value" approach can produce a higher balance sheet value in some circumstances. The inability to reverse write-downs under US GAAP creates a ratchet effect: once written down, inventory stays down.

Reference: IFRS 2 paragraphs 9— 5; ASC 330-10-1 onwards.

More details on inventory valuation →

Provisions and Contingencies

Both standards require a provision when there is a present obligation (legal or constructive) and an outflow is probable and measurable. But they differ on threshold and measurement:

• IFRS: "Probable" means more likely than not (>50% likelihood). Provisions are measured at the present value of the best estimate.
• US GAAP: "Probable" means likely to occur. Contingencies are not recognised unless a loss is probable (similar to IFRS), but measurement uses the most likely amount (not best estimate), and discounting is optional for most items.

The practical effect: IFRS provisions are often larger (present value reduces the nominal amount, but more items qualify as provisions). US GAAP defers many items to disclosure only.

Restructuring example: If you announce a restructuring with a plan but no execution commitment, IFRS recognises a provision; US GAAP may only disclose it as a contingency.

Reference: IFRS 37 paragraphs 1— 9; ASC 450-20-1 onwards.

More details on provisions →

Financial Instruments

IFRS 9 and US GAAP (ASC 320/321) have converged significantly on classification and measurement of financial assets:

• Both require classification based on business model and contractual cash flow characteristics
• Both use amortised cost, fair value through OCI, or fair value through P&L
• Both require expected-credit-loss (ECL) provisions for financial assets

Where they differ:

• Impairment approach: IFRS 9 uses forward-looking expected credit losses; US GAAP uses "current expected credit losses" (CECL), which is similar but has different practical implementation timelines.
• Held-to-maturity securities: IFRS permits reclassification if intent changes; US GAAP is stricter and rarely allows reclassification.
• Debt modification: If you modify a loan's terms, IFRS 9 and US GAAP treat it differently — IFRS may derecognise the old loan; US GAAP may adjust it.

These differences matter most for banks and insurance companies with large investment portfolios.

Reference: IFRS 9 paragraphs 1— 49; ASC 320-10-1, ASC 321-10-1 onwards.

More details on financial instruments →

Presentation and Display

IFRS and US GAAP both allow flexibility in how items are presented, but conventions differ:

• IFRS: Allows classification by nature (e.g., "depreciation by function" or "depreciation by nature"). More flexibility.
• US GAAP: Often requires function-based presentation (cost of sales, operating expenses). More standardised.
• Operating vs financing: Different guidance on what sits "above the line" — IFRS can classify items as financing vs operating more flexibly.

This affects EBITDA and operating profit comparisons — a US GAAP company's EBIT might include financing items that an IFRS company presents separately.

More details on presentation →

Are IFRS and US GAAP Converging?

The IASB and FASB published a joint convergence project over a decade ago. Some standards have converged:

• ✓ Revenue recognition (IFRS 15 / ASC 606) — substantially converged
• ✓ Leases (IFRS 16 / ASC 842) — substantially converged
• ✓ Financial instruments — largely converged (with small differences)
• ✗ Goodwill impairment — still materially different
• ✗ Provisions / contingencies — still different thresholds
• ✗ Inventory / classification — still different

The SEC has not mandated IFRS for US public companies, despite years of discussion. The political and regulatory barriers remain high. Near-term full convergence is unlikely.

Practical Implications for Auditors & CFOs

For auditors:

• Double-check assumptions: When auditing a group with mixed IFRS and GAAP entities, verify that management has applied the correct standard to each. Misapplication is a frequent audit finding.
• Watch goodwill: Goodwill impairment testing is a high-risk area. Ensure the company knows which standard it is applying and whether fair value or value-in-use is being used.
• Lease and revenue edge cases: Most leases and revenue contracts will be similar, but audit the judgments. IFRS principles-based approach allows more latitude — push back on aggressive interpretations.
• Consolidation scope: IFRS and US GAAP differ on control assessment for non-voting shares and special-purpose entities. Ensure consolidation is correct.

For CFOs and controllers:

• Know which standard applies: If you have US-listed parent and IFRS subsidiaries, know the reporting requirement for each.
• Provision timing: If you are restructuring, IFRS recognises provisions earlier than US GAAP. Plan for P&L impact timing.
• EBITDA comparisons: When comparing to peers or debt covenants, ensure like-for-like: a US GAAP EBITDA may not equal an IFRS EBITDA due to presentation differences.
• Lease impact: Both standards have similar lease mechanics, but ensure disclosure is full. Lease-adjusted leverage ratios will look different from statutory ratios.

Frequently Asked Questions

This comparison is simplified for educational purposes and does not constitute professional accounting or audit advice. Actual IFRS vs US GAAP assessments may require consideration of specific transaction facts, scope limitations, and recent standard amendments. The article reflects IFRS Accounting Standards and US GAAP effective as of July 2026. Always consult the full text of IFRS and ASC standards, and your own advisors, before finalising accounting treatment.

Real-Life Case Study: A Dual-Reporting Group Bridging IFRS and US GAAP