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

Of everything on this page, this is the area where the two frameworks really did converge. IFRS 15 and ASC 606 were written jointly and 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 modification guidance is worth stating plainly because it is often misreported: IFRS 15.18 to .21 and ASC 606-10-25-10 to 25-13 are the same requirements. So is the variable consideration constraint. The real differences are narrower and mostly sit in Step 1 and in presentation.

• Collectibility. Both require it to be probable that the entity will collect the consideration before a contract exists. But probable means more likely than not under IFRS and likely to occur under US GAAP. A marginal-credit customer can therefore clear Step 1 under IFRS and fail it under ASC 606.
• Shipping and handling. ASC 606 gives an accounting policy election to treat activities performed after control passes as a fulfilment cost rather than a separate performance obligation. IFRS 15 has no such election.
• Sales taxes. ASC 606 offers a practical expedient to present revenue net of all taxes collected from customers. Under IFRS the entity has to assess, tax by tax, whether it is acting as principal or agent.
• Non-cash consideration. US GAAP fixes the measurement date at contract inception. IFRS 15 does not specify a date, so practice varies.
• Licensing. ASC 606 uses a functional and symbolic intellectual property taxonomy and has a specific rule on the timing of licence renewals. IFRS 15 reaches similar answers through the right to use and right to access analysis, but the routes differ and the renewal timing can differ with them.
• Contract cost impairment. IFRS 15.104 requires reversal when the impairment conditions no longer exist. ASC 340-40-35-6 prohibits reversal.

Reference: IFRS 15.9(e), .18 to .21, .56 to .58, .99, .104, B52 to B63; ASC 606-10-25-1(e), 25-10 to 25-13, 25-18B, 32-2A, 32-11, 55-58C; ASC 340-40-35-6.

More details on revenue recognition →

Lease Accounting: IFRS 16 vs ASC 842

The balance sheets converged. The income statements did not, and that is the difference people miss.

Both standards put substantially all leases on the lessee's balance sheet as a right-of-use asset and a lease liability, measured the same way: the liability at the present value of unpaid lease payments, the asset at that liability plus prepayments and initial direct costs, less incentives received.

Where they genuinely differ:

• ASC 842 keeps a dual lessee model. IFRS 16 does not. This is the big one. Under IFRS 16 every lease is treated like a financed purchase: depreciation on the asset plus interest on the liability, so the total charge is front-loaded and the interest sits below EBITDA. Under ASC 842 a lease still has to be classified. A finance lease behaves like IFRS 16. An operating lease produces a single straight-line lease cost, sitting entirely in operating expenses. Same lease, same balance sheet, materially different EBITDA and a different profit profile over the term.
• Restoration and dismantling costs. IFRS 16.24(d) includes them in the right-of-use asset. Under US GAAP they are accounted for separately as an asset retirement obligation under ASC 410-20. Note that under neither standard do they go into the lease liability, which is a common error.
• Payments linked to an index or rate. IFRS 16.42(a) requires the lessee to remeasure the liability when the cash flows change, for example on a CPI uplift. ASC 842 does not: the incremental amount is recognised as variable lease cost in the period incurred, and the liability is left alone. Over a long indexed property lease this diverges substantially.
• Low-value exemption. IFRS 16 has one, applied lease by lease. ASC 842 has none. The FASB considered a low-value exemption and rejected it. A US filer only has the short-term election, made by class of underlying asset. Laptops, phones and small equipment go on balance sheet under US GAAP.
• Lessor accounting. IFRS 16 classifies on a risks-and-rewards assessment with non-quantified indicators. ASC 842 applies five specified criteria including quantified "major part" and "substantially all" thresholds, and splits lessor finance leases into sales-type and direct financing.

So the headline is that the balance sheet impact is broadly similar and the income statement impact is not. If you are reconciling a dual-reporting group, the operating lease population is where the reconciling items live.

Reference: IFRS 16.22 to .46 (lessee recognition and measurement) and IFRS 16.61 to .66 (lessor classification); ASC 842-20-25-2 and 25-6 (lessee classification and operating lease cost), ASC 842-20-30-5 (ROU asset), ASC 842-10-35-4 (index-linked payments).

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: Single-Step Test

Compare the fair value of the reporting unit to its carrying amount (including goodwill). If fair value exceeds carrying amount, no impairment. If it does not, impair by the shortfall, capped at the carrying amount of goodwill allocated to that reporting unit.

This is a change worth knowing if you trained on the old model. ASU 2017-04 removed Step 2, the hypothetical purchase price allocation that computed an "implied" fair value of goodwill. It has applied to public business entities for fiscal years beginning after 15 December 2019, and to all other entities for fiscal years beginning after 15 December 2022. Private entities can also elect to amortise goodwill and test only on a triggering event under the private company alternative in ASC 350-20.

Practical impact: IFRS often produces a lower impairment, because value in use is based on the entity's own cash flow projections rather than market fair value. In down markets, US GAAP write-downs can be larger. The IFRS test can also reverse for assets other than goodwill; goodwill impairment is never reversed under either framework.

Reference: IAS 36 paragraphs 80-99 (goodwill and CGU impairment testing); ASC 350-20, as amended by ASU 2017-04.

More details on goodwill impairment →

Inventory Valuation

This area narrowed considerably in 2015 and a lot of material still in circulation has not caught up. ASU 2015-11 moved US GAAP to lower of cost and net realisable value for inventory measured on FIFO or weighted average, which is the same basis as IAS 2. The old lower of cost or market test, with its replacement cost ceiling and floor, survives only for inventory measured using LIFO or the retail inventory method.

So for a FIFO manufacturer the measurement bases now agree, and the two live differences are LIFO availability and reversal. Reversal creates a ratchet under US GAAP: once written down, the new figure becomes cost and inventory stays there even if prices recover. Under IAS 2.33 the same recovery reverses the write-down back up to original cost, so identical inventory can carry different values purely because of a past price movement.

Reference: IAS 2.9 and .33 to .34; ASC 330-10-35-1B and 35-1C (as amended by ASU 2015-11), ASC 330-10-35-14 (no reversal).

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Provisions and Contingencies

Both frameworks recognise a liability when a present obligation exists and an outflow is probable and measurable. The trap is that the word "probable" means two different things.

• IFRS: probable means more likely than not, so anything above 50%. Provisions are measured at the best estimate of the expenditure required, discounted where the time value of money is material.
• US GAAP: probable means likely to occur, a materially higher hurdle. There is no percentage in ASC 450, but it is commonly read in practice as somewhere around 75% and up. This single word is why US GAAP recognises fewer provisions than IFRS on identical facts.

Measurement of a range also differs, and in opposite directions. Where the outcome is a range and no point in it is a better estimate than any other, IAS 37.39 uses the midpoint. ASC 450-20-30-1 accrues the minimum of the range. On a £2m to £10m litigation exposure that is £6m under IFRS against £2m under US GAAP, before you even reach the recognition threshold.

Discounting differs too. IAS 37.45 requires it where material. ASC 450 generally does not permit it unless the timing and amount of the payments are fixed or reliably determinable, with environmental obligations under ASC 410-30 as the notable exception.

Restructuring is not an ASC 450 question. US GAAP deals with it under ASC 420 Exit or Disposal Cost Obligations, and the frameworks are closer than most comparisons suggest. IAS 37.72 requires both a detailed formal plan and a valid expectation raised in those affected, by starting to implement it or announcing its main features to them. A board decision alone does not create a constructive obligation. ASC 420-10-25-4 requires one-time termination benefits to be communicated to employees. Both turn on communication, not on the internal decision.

Reference: IAS 37.14, .23, .36, .39, .45, .72 to .78; ASC 450-20-25-2 and 450-20-30-1; ASC 420-10-25-4; ASC 410-30.

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Financial Instruments

This is the widest remaining gap between the two frameworks, not a convergence story. The FASB left the joint financial instruments project in 2014 without a converged answer, and the models that resulted are built on different foundations.

Classification works differently at the root. IFRS 9 classifies a financial asset on two objective tests: the business model within which it is held, and whether its contractual cash flows are solely payments of principal and interest. US GAAP has neither test. ASC 320 classifies debt securities as trading, available-for-sale or held-to-maturity based on management intent and ability. ASC 321 requires equity investments to be held at fair value through net income, with a measurement alternative for those without a readily determinable fair value. There is no available-for-sale category for equities under US GAAP and no FVOCI option, other than the separate irrevocable election IFRS 9 offers for equities not held for trading.

Impairment differs in the measure, not the timetable. IFRS 9 runs a three-stage model: a 12-month expected credit loss on initial recognition, moving to lifetime ECL only when credit risk has increased significantly. ASC 326 CECL requires lifetime expected losses from day one on everything in scope, with no staging. That produces a materially larger day-one allowance on a performing loan book. Available-for-sale debt securities are the exception on the US side: ASC 326-30 caps the allowance at the amount by which fair value is below amortised cost, which is a different model again.

Reclassification. IFRS 9 has no held-to-maturity category; it went with IAS 39. Reclassification under IFRS 9 is permitted only when the entity changes its business model for managing financial assets, which the standard says is expected to be very infrequent, and a change of intention for a single instrument is expressly not a change in business model. Equity investments and fair value option designations are never reclassified.

Modification of a financial liability. IFRS 9 uses a quantitative 10% test on discounted cash flows, with a qualitative overlay, and derecognises where the terms are substantially different. US GAAP has its own troubled debt restructuring and modification-versus-extinguishment analysis. The answers frequently differ on the same amendment.

These differences bite hardest for banks and insurers, but any group with a debt securities portfolio or intercompany loans will meet them on consolidation.

Reference: IFRS 9.4.1.1 to 4.1.5, 4.4.1, 5.5.3, 5.5.5, 5.7.5, B3.3.6; ASC 320-10-25-1, ASC 321-10-35-1 and 35-2, ASC 326-20-30-1, ASC 326-30-35-1.

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Presentation and Display

This section is about to date itself, so it is worth reading with the effective dates in mind.

Today, under IAS 1. An entity analyses expenses either by nature (raw materials, employee benefits, depreciation) or by function (cost of sales, distribution, administrative), whichever is reliable and more relevant. IAS 1 does not define operating profit at all, which is why "operating profit" has meant slightly different things at different IFRS reporters. US GAAP has no general requirement to present expenses by function either, but SEC Regulation S-X Rule 5-03 requires commercial registrants to show cost of sales separately, which produces a more uniform-looking income statement in practice.

From 1 January 2027, under IFRS 18. IFRS 18 replaces IAS 1 and closes most of that flexibility. It requires income and expenses to be classified into three defined categories, operating, investing and financing, and mandates an operating profit subtotal plus, for most entities, a profit before financing and income taxes subtotal. Entities whose main business is providing financing to customers, such as banks, classify financing items in operating and are not required to present the second subtotal. IFRS 18 also requires management-defined performance measures to be disclosed and reconciled, which brings adjusted EBITDA-style metrics inside the audited financial statements for the first time. Early application is permitted.

On the US side, ASU 2024-03 requires disaggregation of certain income statement expense captions, effective for annual periods beginning after 15 December 2026. So both frameworks are moving toward more granular expense information at roughly the same time, from opposite starting points.

The practical consequence today is that operating profit and EBITDA are not reliably comparable across the two frameworks, and the IFRS 16 lease treatment discussed above is one of the larger reasons why. That comparability problem is precisely what IFRS 18 is intended to fix.

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): genuinely converged. Same five steps, same core principle, and the modification and constraint guidance is identical text. The residual differences are narrow, mainly the collectibility threshold, shipping and handling, sales taxes, non-cash consideration and contract cost impairment reversal.
• Leases (IFRS 16 / ASC 842): converged on the balance sheet, not on the income statement. ASC 842 keeps a dual lessee model and IFRS 16 does not, so operating leases still drive an EBITDA difference.
• Inventory (IAS 2 / ASC 330): partly converged since ASU 2015-11. Same measurement basis for FIFO and weighted average, still divided on LIFO and on reversal.
• Goodwill impairment: materially different, and both frameworks moved separately rather than together.
• Provisions and contingencies: different recognition threshold and opposite ends of a range on measurement.
• Financial instruments: not converged. The FASB left the joint project in 2014. Classification, impairment and hedge accounting are each built on different models.

The pattern is that where the boards drafted a standard jointly, it converged. Where they drafted separately after 2014, it did not, and in some areas the gap has widened.

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

About the author — Usman Qureshi (ACCA)

Usman Qureshi is a Chartered Certified Accountant (ACCA) working in audit and advisory. He writes on the practical differences between IFRS and US GAAP.

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