Outliers Professionals LtdOutliersProfessionals · Ltd
Knowledge Centre · IFRS

IAS 21

The Effects of Changes in Foreign Exchange Rates

IAS 21 prescribes how an entity determines its functional currency, translates foreign currency transactions and balances into that functional currency, and translates the results and financial position of foreign operations (and, where different, into a presentation currency), so that the effects of exchange rate changes are reported consistently. [S1]

Effective 2005-01-01Related: IAS 1 · IAS 16 · IAS 36 · IAS 29

Overview

IAS 21 works in two stages: first, translating individual foreign currency transactions and balances into an entity's own functional currency (the currency of its primary economic environment); second, where an entity presents in a different currency, or consolidates a foreign operation with a different functional currency, translating the whole set of financial statements into the presentation currency. [S1] Monetary items are retranslated at the closing rate at each reporting date; non-monetary items measured at historical cost are not retranslated after initial recognition; non-monetary items measured at fair value are translated at the rate when that fair value was determined. [S2]

Why it matters

For entities operating in a volatile-currency environment, the choice of functional currency, and the mechanics of translating foreign-currency balances, can swing reported profit and net assets by a large margin independent of the underlying business performance. Getting this wrong either overstates or understates FX exposure to lenders, investors and the board, and can mask or exaggerate genuine operating performance.

Scope

Applies to accounting for transactions and balances in foreign currencies, except for derivative transactions and balances within the scope of IFRS 9 (other than derivatives not accounted for under IFRS 9, e.g. some derivatives on non-financial items), to translating the results and financial position of foreign operations included in an entity's financial statements, and to translating an entity's results and financial position into a presentation currency. It does not apply to hedge accounting for foreign currency items, which is addressed in IFRS 9, nor does it specify the currency in which an entity presents its financial statements, though it does specify how translated amounts should be determined.

Key definitions

term
Functional currency
definition
The currency of the primary economic environment in which the entity operates.
term
Presentation currency
definition
The currency in which the financial statements are presented.
term
Foreign currency
definition
A currency other than the functional currency of the entity.
term
Exchange difference
definition
The difference resulting from translating a given number of units of one currency into another currency at different exchange rates.
term
Closing rate
definition
The spot exchange rate at the end of the reporting period.
term
Monetary items
definition
Units of currency held and assets/liabilities to be received or paid in a fixed or determinable number of units of currency.
term
Foreign operation
definition
An entity that is a subsidiary, associate, joint arrangement or branch of the reporting entity, the activities of which are based or conducted in a country or currency other than those of the reporting entity.

Recognition

A foreign currency transaction is recorded, on initial recognition, by applying the spot exchange rate between the functional currency and the foreign currency at the date of the transaction (a rate that approximates the actual rate may be used, e.g. an average rate for a week, if exchange rates do not fluctuate significantly). At the end of each subsequent reporting period, monetary items are retranslated using the closing rate; non-monetary items carried at historical cost are not retranslated; non-monetary items carried at fair value are translated using the exchange rate at the date the fair value was measured.

Initial measurement

Initial measurement of a foreign currency transaction uses the spot rate (or an approximating rate) at the date the transaction first qualifies for recognition. Where the exchange rate is not readily determinable because a currency lacks exchangeability into another currency, IAS 21 (as amended in 2023) requires the entity to estimate the spot rate at the measurement date using an observable rate, adjusted if necessary to reflect a rate at which an orderly transaction would take place, and to disclose that estimation.

Subsequent measurement

Exchange differences arising on settling monetary items, or on retranslating monetary items at rates different from those at initial recognition (or the previous reporting date), are recognised in profit or loss in the period in which they arise, except for certain exchange differences on a net investment in a foreign operation, which are recognised in other comprehensive income and reclassified to profit or loss on disposal of the foreign operation. For non-monetary items carried at fair value with changes recognised in other comprehensive income (e.g. certain equity investments), the exchange component of that fair value change is also recognised in other comprehensive income.

Presentation

Where an entity's functional currency differs from its presentation currency, or on consolidation of a foreign operation with a different functional currency, assets and liabilities are translated at the closing rate, income and expenses are translated at exchange rates at the dates of the transactions (or an average rate as an approximation), and all resulting exchange differences are recognised in other comprehensive income and accumulated in a separate component of equity (the foreign currency translation reserve), reclassified to profit or loss on disposal of the foreign operation.

Disclosure checklist

  • The amount of exchange differences recognised in profit or loss, excluding those arising on financial instruments measured at fair value through profit or loss.
  • Net exchange differences accumulated in a separate component of equity, and a reconciliation of that amount at the beginning and end of the period.
  • The fact and reason when the presentation currency differs from the functional currency.
  • A description of any change in functional currency and the reason for the change.
  • When an entity displays its financial statements or other financial information in a currency that differs from its functional or presentation currency, a statement that this additional information is not IFRS-compliant translated information if applicable requirements are not met.
  • For currencies without exchangeability, the nature and financial effect of the lack of exchangeability, the spot exchange rate used, and the estimation techniques or assumptions applied.

Practical treatment

The threshold judgement is determining functional currency, not simply defaulting to the local currency of incorporation: indicators include the currency that mainly influences sale prices, the currency of the country whose competitive forces and regulations mainly determine sale prices, and the currency that mainly influences labour, material and other costs. An entity invoicing predominantly in US dollars, financed in US dollars, and competing internationally may have a US dollar functional currency even if it is incorporated and pays some local costs in naira. Once determined, functional currency is not changed unless there is a genuine change in the underlying transactions, events and conditions. See nigeria_notes for the practical implications of Nigeria's foreign exchange market structure and volatility.

Common mistakes

  • Assuming functional currency is automatically the currency of incorporation or the currency used for statutory filings, without assessing the actual primary economic indicators.
  • Retranslating non-monetary items carried at historical cost (e.g. PPE, inventory at cost) at the closing rate, when only monetary items are retranslated.
  • Recognising exchange differences on ordinary trading balances in other comprehensive income, when only specific net-investment-in-a-foreign-operation differences qualify for OCI treatment.
  • Using a single official rate for translation when a portion of transactions is actually settled at a materially different rate in practice, without considering whether that indicates a lack of exchangeability requiring the 2023 amendments' estimation approach.
  • Changing functional currency opportunistically (e.g. to manage a reported FX loss) without a genuine underlying change in the primary economic environment.

CFO checklist

  • Document the functional currency assessment for each entity in the group with reference to the specific IAS 21 indicators, not just the currency of incorporation.
  • Confirm the accounting system correctly distinguishes monetary from non-monetary items for retranslation purposes.
  • Reconcile exchange differences recognised in profit or loss against treasury/FX exposure reports each period, to catch misclassification early.
  • For any foreign operation, confirm whether its functional currency differs from the group presentation currency and that consolidation translation procedures are applied correctly.
  • Monitor official versus parallel-market rate gaps and document which rate is used and why, particularly where the CBN rate diverges from rates actually achievable for the entity's transactions.

FAQs

q
We're a Nigerian company that invoices customers in US dollars and imports most of our inventory — is our functional currency the naira or the dollar?
a
It depends on which currency mainly influences your sale prices and costs, not simply which currency you invoice in; if the dollar mainly determines your pricing, financing and cost structure, the dollar may be your functional currency even though you're incorporated in Nigeria and file statutory accounts in naira. This is a judgement that should be documented, not assumed.
q
Do we retranslate our naira cash balances at each year-end?
a
Naira cash held by a naira-functional-currency entity is not a foreign currency item and is not retranslated. Foreign-currency cash and bank balances held by that same entity are monetary items and are retranslated at the closing rate at each reporting date.
q
Which CBN rate should we use to translate a foreign currency transaction?
a
IAS 21 requires the spot rate at the transaction date (or an approximating rate); which published rate best represents that spot rate depends on which market the entity actually transacts in, and should be applied consistently and disclosed. See nigeria_notes for the current official rate structure.

Nigeria application notes

Regulatory overlay

IAS 21 applies in full to Nigerian public interest entities under the FRCN Act 2011 mandate. [S3] The Central Bank of Nigeria unified the foreign exchange market in 2023 onto a single 'willing buyer, willing seller' Nigerian Foreign Exchange Market (NFEM, formerly the Investors' & Exporters' window), replacing the previous multiple-rate segmented structure. [S6]

Tax interaction (Nigeria)

Realised and unrealised foreign exchange gains and losses recognised under IAS 21 generally feed into taxable profit computations under the Nigeria Tax Act 2025, but the tax treatment of unrealised (translation) FX gains and losses can differ from their accounting treatment and should be confirmed against current NRS guidance rather than assumed to mirror the accounting entries directly; this file does not give tax advice on the point. [S_TAX1]

FX considerations

The NFEM's official Volume Weighted Average rate is published daily by the CBN and stands as the reference official exchange rate for the day; entities should identify which specific published rate (NFEM close, an average, or another observable rate) they use for transaction-date and closing-rate translations, apply it consistently, and disclose the basis. [S5] Where a gap persists between the official NFEM rate and rates actually achievable by the entity for its specific transactions (for example where liquidity for a particular transaction size or currency pair is constrained), this may indicate a lack of exchangeability requiring the estimation approach introduced by the 2023 amendments to IAS 21, and should be assessed rather than assumed away. Naira interest-rate and reserve conditions published in CBN Monetary Policy Committee decisions are useful context for assessing the stability of the rate environment period to period. [S7]

SME practical note

Smaller Nigerian importers and distributors often use the rate at which they actually settled a transaction with their bank (which can differ from the CBN's published NFEM rate) as a practical proxy for the transaction-date spot rate; this is acceptable as an approximating rate only if it does not fluctuate significantly from the true spot rate and is applied consistently, and the basis used should be documented in the accounting policy note.

Common Nigerian pitfalls

  • Defaulting to naira as functional currency for every Nigerian-incorporated entity without assessing the actual primary economic environment indicators.
  • Using an outdated or unofficial parallel-market rate for translation without documenting why it better approximates the transaction-date spot rate than the published NFEM rate.
  • Failing to reassess whether the FRCN's 'not hyperinflationary' position still holds for the current reporting year before finalising foreign-operation translation.
  • Assuming unrealised FX translation gains/losses are taxed identically to realised FX gains/losses without checking current NRS treatment.

FRC pronouncements

The FRCN issued a formal position statement in January 2025 (reaffirmed for the 2025 financial year) concluding that Nigeria is not a hyperinflationary economy for IAS 29 purposes, despite a three-year cumulative inflation rate exceeding the indicative 100% threshold, based on its assessment of the full set of IAS 29 indicators; this directly affects whether IAS 29 restatement is layered onto IAS 21 translation for Nigerian foreign operations, and should be checked for whether the FRC has issued or updated its position for the current reporting year before finalising translation procedures. [S4]

Worked examples

Retranslation of a foreign-currency trade payable at year-end

A Nigerian company (naira functional currency) purchases equipment from a US supplier for US$100,000 on 1 November, when the spot rate is ₦1,350/US$1, recorded on credit terms. At the 31 December year-end, the closing spot rate is ₦1,400/US$1. The payable remains outstanding at year-end.

Facts

Workings

Initial recognition: US$100,000 x 1,350 = 135,000,000

Closing retranslation: US$100,000 x 1,400 = 140,000,000

Exchange loss (payable increases in naira terms as the naira weakens): 140,000,000 - 135,000,000 = 5,000,000

Journal entries

Initial recognition of equipment purchase and trade payable at the transaction-date spot rate.

AccountDr (₦)Cr (₦)
Property, plant and equipment – equipment (in transit/under installation)135,000,000
Trade payables (foreign currency)135,000,000

Retranslate the outstanding foreign-currency trade payable at the closing rate and recognise the exchange loss in profit or loss.

AccountDr (₦)Cr (₦)
Foreign exchange loss (profit or loss)5,000,000
Trade payables (foreign currency)5,000,000

Translating a foreign subsidiary's results for consolidation

A Nigerian parent (naira presentation currency) consolidates a Ghanaian subsidiary whose functional currency is the Ghanaian cedi. The subsidiary's net assets at the start of the year translate to ₦900,000,000 at the opening rate; at the closing rate, the same cedi net asset balance (before current-year profit) translates to ₦950,000,000. The translation difference is not related to any disposal in the period.

Facts

Workings

Translation difference arising purely from the movement in the closing rate applied to opening net assets: 950,000,000 - 900,000,000 = 50,000,000

This difference is a consolidation translation adjustment, not a transaction gain or loss, and is recognised in other comprehensive income.

Journal entries

Recognise the foreign currency translation adjustment arising on consolidating the Ghanaian subsidiary's net assets at the closing rate.

AccountDr (₦)Cr (₦)
Net assets of foreign operation (consolidation translation adjustment)50,000,000
Foreign currency translation reserve (other comprehensive income / equity)50,000,000

Sources & citations

  1. [S1]IAS 21 The Effects of Changes in Foreign Exchange Rates — IFRS Foundationaccessed 2026-07-18
  2. [S2]IAS 21 — Effects of Changes in Foreign Exchange Rates — IFRS Communityaccessed 2026-07-18
  3. [S3]IFRS - Use of IFRS Standards by jurisdiction: Nigeria — IFRS Foundationaccessed 2026-07-18
  4. [S4]FRC's Position on IAS 29 – Financial Reporting in Hyperinflationary Economies — Financial Reporting Council of Nigeriaaccessed 2026-07-18
  5. [S5]Exchange Rates (NFEM, official) — Central Bank of Nigeriaaccessed 2026-07-18
  6. [S6]Foreign Exchange Market — Central Bank of Nigeriaaccessed 2026-07-18
  7. [S7]Monetary Policy Decisions — Central Bank of Nigeriaaccessed 2026-07-18
  8. [S_TAX1]Nigeria Tax Act, 2025 has been signed – highlights — EY Globalaccessed 2026-07-18
Last reviewed 2026-07-18 · Reviewer: Rafiu Olawuyi, FCA (Author / Technical Reviewer)