Converting from US GAAP to IFRS

US companies convert to IFRS when they are bought by a foreign group, list outside the US, or report to an IFRS parent. The work is mostly in the opening balance sheet. This guide explains IFRS 1, the main exemptions, the adjustments that usually arise, and shows an equity reconciliation.

By Mirza Fahad Baig, Chartered Accountant. Reviewed by Hamza Fida, Chartered Accountant. 3 minute read.

Short answer

A US GAAP to IFRS conversion follows IFRS 1 First-time Adoption. The company prepares an opening IFRS statement of financial position at the date of transition, the start of the earliest comparative period, applying the IFRS standards in force at its first reporting date retrospectively, subject to mandatory exceptions and optional exemptions. Typical adjustments include replacing LIFO, capitalising development costs, reversing impairments and recalculating deferred tax. The first IFRS financial statements reconcile equity and comprehensive income from US GAAP to IFRS.

At a glance

Standard
IFRS 1 First-time Adoption
Opening balance sheet
At the date of transition
Approach
Retrospective, with exceptions and exemptions
Common adjustments
LIFO, development costs, impairments, leases
Required
Reconciliations of equity and income
Typical triggers
Foreign parent, overseas listing
Converting from US GAAP to IFRSStandard: IFRS 1 First-time Adoption; Opening balance sheet: At the date of transition; Approach: Retrospective, with exceptions and exemptions; Common adjustments: LIFO, development costs, impairments, leases; Required: Reconciliations of equity and income; Typical triggers: Foreign parent, overseas listing.KEY FACTS AT A GLANCEConverting from US GAAP to IFRSStandardIFRS 1 First-timeAdoptionOpening balance sheetAt the date of transitionApproachRetrospective, withexceptions and exemptionsCommon adjustmentsLIFO, development costs,impairments, leasesRequiredReconciliations of equityand incomeTypical triggersForeign parent, overseaslistingTax BakersConverting from US GAAP to IFRSStandard: IFRS 1 First-time Adoption; Opening balance sheet: At the date of transition; Approach: Retrospective, with exceptions and exemptions; Common adjustments: LIFO, development costs, impairments, leases; Required: Reconciliations of equity and income; Typical triggers: Foreign parent, overseas listing.KEY FACTS AT A GLANCEConverting from US GAAP to IFRSStandardIFRS 1 First-time AdoptionOpening balance sheetAt the date of transitionApproachRetrospective, with exceptions andexemptionsCommon adjustmentsLIFO, development costs, impairments, leasesRequiredReconciliations of equity and incomeTypical triggersForeign parent, overseas listingTax Bakers
Key facts at a glance, as set out in this guide.

How does a US GAAP to IFRS conversion work?

  1. Choose the dates. For first IFRS financial statements for the year ending 31 December 2027 with one comparative year, the date of transition is 1 January 2026.
  2. Prepare the opening IFRS balance sheet at the date of transition: recognise all assets and liabilities IFRS requires, derecognise those it does not allow, reclassify items and measure everything under IFRS.
  3. Apply the exceptions and choose exemptions.
  4. Recognise the adjustments in retained earnings or another category of equity at the date of transition.
  5. Explain the transition with reconciliations of equity and total comprehensive income.

What exceptions and exemptions does IFRS 1 offer?

  • Mandatory exceptions stop hindsight: estimates must be consistent with those made under US GAAP unless they were in error, and hedge accounting, derecognition and non-controlling interest rules apply prospectively.
  • Optional exemptions reduce cost: past business combinations need not be restated; fair value or a previous revaluation can be used as deemed cost for property; cumulative translation differences can be reset to zero; and there are reliefs for leases, share-based payments and decommissioning liabilities.

An example equity reconciliation

US GAAP to IFRS equity reconciliation ($ million)US GAAP to IFRS equity reconciliation ($ million)1,000US GAAPequity+40LIFO toFIFO+30Developmentcosts+15Impairmentreversal-25Leasesand other-15Deferredtax1,045IFRSequity
Each difference becomes a line in the IFRS 1 reconciliation.

A US company with equity of $1,000 million under US GAAP converts to IFRS. Replacing LIFO with FIFO increases inventory by $40 million; capitalising development costs meeting IAS 38 adds $30 million; an earlier impairment of equipment that IFRS requires to be reversed adds $15 million; lease and other adjustments reduce equity by $25 million; and deferred tax on the net adjustments of $60 million, at 25%, reduces equity by $15 million. Equity under IFRS is $1,045 million.

Where do adjustments usually arise?

AreaTypical adjustment
InventoryLIFO replaced by FIFO or weighted average
Development costsCapitalised when IAS 38 criteria are met
ImpairmentRecalculated without the undiscounted screen; earlier losses may reverse
LeasesOperating leases remeasured under the IFRS 16 single model
ProvisionsLower threshold, midpoint of ranges, discounting
Financial instrumentsReclassified under IFRS 9; ECL replaces CECL
Deferred taxRecalculated on all adjustments; valuation allowances replaced by the probable test

How long does a conversion take?

For a mid-sized company, typically 12 to 18 months before the first IFRS reporting date, because the comparative year must be captured under IFRS too. Most projects start with a diagnostic of differences, then policy choices and IFRS 1 elections, then the opening balance sheet, then parallel running of the comparative year alongside US GAAP reporting.

What changes beyond the numbers?

The accounting adjustments are often the easier part. Conversion also affects charts of accounts, consolidation systems, tax calculations, debt covenants defined using US GAAP measures, management bonuses based on reported profit, and staff training across finance teams. Covenants and contracts referring to US GAAP figures often need renegotiating or a frozen-GAAP clause.

Does the SEC accept IFRS?

Foreign private issuers may file financial statements prepared under IFRS as issued by the IASB without reconciling to US GAAP. US domestic registrants must use US GAAP. See the IFRS vs US GAAP cheat sheet and the key differences.

Need help applying the standards?

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Questions people ask

How do you convert from US GAAP to IFRS?

Under IFRS 1: prepare an opening IFRS balance sheet at the date of transition, apply IFRS retrospectively subject to exceptions and exemptions, and reconcile equity and income from US GAAP to IFRS.

What is the date of transition to IFRS?

The beginning of the earliest period for which full comparative IFRS information is presented.

What adjustments usually arise when converting to IFRS?

LIFO replacement, capitalised development costs, impairment differences, leases, provisions, financial instruments and deferred tax.

Can a US company file IFRS financial statements with the SEC?

Foreign private issuers can, using IFRS as issued by the IASB; US domestic registrants must use US GAAP.

Sources

Every fee, date and rule on this page was taken from these official and primary sources.

  1. IFRS Foundation: IFRS Accounting Standards
  2. FASB Accounting Standards Codification
  3. IFRS Foundation: IFRS 1 First-time Adoption of IFRS

Rules and fees change. If you are reading this long after October 4, 2026, confirm the figures with the source before you rely on them.

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This guide is general information. It is not tax or legal advice for your situation.