Foreign exchange differences in Luxembourg: LuxGAAP

How are foreign exchange differences in Luxembourg treated at closing?

Foreign exchange differences in Luxembourg arise at closing when receivables and payables denominated in another currency are translated at the closing rate and compared with the rate first recorded. The difference is realised if the transaction has settled, unrealised otherwise, and the prudence principle requires the unrealised loss to be booked while the symmetrical gain is not.

That asymmetry is not a market practice, it is the statute. The prudence principle of the amended law of 19 December 2002 provides that only profits actually realised at the balance sheet date may be included in it, and the Commission des normes comptables ties the fate of unrealised exchange gains expressly to that realisation rule. A probable loss is recognised; a hoped-for profit waits for settlement.

What happens next depends on the translation method chosen, and no single standard settles the matter. Q&A CNC 22/027 describes three accepted practices under the LuxGAAP regime: the classic approach, the monetary versus non-monetary approach, and the short-term versus long-term approach. On a trade receivable due in three months all three converge. On a five-year intra-group loan they diverge, and the gap reads straight through to the result.

Two neighbouring questions must be kept apart, and conflating them is expensive at audit. The currency in which the books are kept and the annual accounts drawn up is covered in our article on annual accounts in a foreign currency. This article addresses the other question: what becomes of items denominated in a currency other than that of the accounts, whatever that currency is.

What is the difference between an unrealised and a realised exchange difference?

An exchange difference is realised in Luxembourg when the transaction is settled — the receivable collected, the payable paid, the currency actually converted — and unrealised when it results only from restating an item that is still open at the balance sheet date.

The boundary does not always sit where one expects. The Commission des normes comptables treats foreign currency bank balances as a special case: restating them at the closing rate produces gains and losses regarded as realised and recorded as such in the profit and loss account. The reasoning is economic as much as legal, since a dollar balance on demand can be converted the same day, which leaves the difference nothing conditional about it.

The distinction governs three decisions, which is why it comes before any choice of rate. It decides whether the difference enters the result, whether the resulting profit can be distributed, and whether the difference survives in the tax balance sheet. A realised difference passes all three filters; an unrealised one is stopped by at least one.

The practical consequence at the start of an engagement is that a trial balance alone will not do. Item by item, you need to know whether a foreign currency balance corresponds to a transaction still open at closing or to one settled during the year, and the audit trail must allow that to be reconstructed two years later.

Which translation approaches does the Commission des normes comptables accept?

The Commission des normes comptables accepts three approaches to translating foreign currency balances in Luxembourg: the classic approach, the monetary versus non-monetary approach and the short-term versus long-term approach. None is mandatory, but none may be picked item by item either.

The classic approach is the most prudent and the most common in smaller structures. Current assets other than cash are carried at the lower of the historical rate value and the closing rate value, so only the unrealised loss is recognised and the unrealised gain is not. Symmetrically, liabilities are carried at the higher of the two. By construction the result therefore carries every loss and no unsettled gain.

The monetary versus non-monetary approach is the one closest to international reasoning. Monetary items — receivables and payables, short-term and long-term alike, and cash — are restated at the closing rate, and unrealised differences in both directions go to the profit and loss account. Non-monetary items, a fixed asset acquired in a foreign currency for instance, generate no exchange difference in principle. The unrealised gain that is booked nevertheless remains undistributable, which is the subject of the next section.

The short-term versus long-term approach confines restatement at the closing rate to short-term assets and liabilities. Its logic is one of cash: only what will settle within twelve months is restated. It also produces the widest gap with the other two on long-dated intra-group financing, which stays at its original rate until maturity or early repayment.

The choice is made once and then held. Accounting and valuation methods may not be changed from one financial year to the next, asset and liability items are valued separately, and the methods used are disclosed in the notes to the annual accounts. Switching approach mid-stream is not a presentational improvement: it is a break in comparability that must be explained and quantified.

Is an unrealised exchange gain distributable in Luxembourg?

An unrealised exchange gain is not distributable in Luxembourg, even where the translation approach chosen has taken it through the profit and loss account: the Commission des normes comptables excludes it from distributable amounts under the prudence principle, because it is not a profit realised at the balance sheet date.

Accounting profit and distributable profit therefore stop coinciding, which regularly surprises directors. A financial year may show a profit of one hundred thousand euros of which forty thousand come from restating a dollar-denominated loan: only sixty thousand are available for distribution, and the difference stays on the balance sheet until the loan is repaid.

The mechanism is explicit under the optional fair value regime. The amended law of 19 December 2002 provides there that unrealised income and gains, net of tax, are allocated to a non-distributable reserve, either directly on recognition or when the result for the year is appropriated. That reserve may not be used for a capital increase by incorporation of reserves nor to fund the legal reserve, and it is released as and when the gains are realised.

Three steps are enough to secure the distribution decision. Isolate the unrealised gain in a separate account on recognition, disclose its amount in the notes, and deduct it explicitly in the minutes appropriating the result. A distribution computed on gross profit without that deduction is a disguised repayment of capital, and the consequences reach the management body.

How are exchange differences treated in the Luxembourg tax balance sheet?

The Luxembourg tax balance sheet does not mechanically carry over the exchange differences of the commercial balance sheet: article 40 L.I.R. requires that carry-over only where the tax rules do not themselves fix an amount, and article 23 L.I.R. fixes one, both for assets of the net invested assets and for debts.

The valuation rule is a ceiling coupled with an option to go lower. The assets concerned are carried at their acquisition or production cost, and the going-concern value may be used only where it is lower than that cost. Article 23 adds that debts are valued by applying that same provision as appropriate, which the Administration des contributions directes renders, in its thematic guidance, as carrying debts at acquisition cost and using the going-concern value only where it is higher.

Read that way, the tax mechanics reproduce the accounting asymmetry and reinforce it in one case. The unrealised exchange loss has its place, since a lower going-concern value is admitted on the asset side and a higher one on the liability side.

The unrealised exchange gain, by contrast, runs into the acquisition cost ceiling: a company that has booked it because it applies the monetary approach must therefore reverse it to prepare its corporate income tax return, a restatement we go through item by item as a licensed accountant in Luxembourg. We flag that this consequence is a reading of articles 23 and 40, not the restatement of a circular: none of the administrative material consulted puts it in those terms.

A neighbouring case has its own instructions, which should not be transposed. Where the books are kept in a foreign currency, circular L.G.-A no. 60 organises the translation of the balance sheet for tax purposes: European Central Bank rates serve as the reference, short-term assets are in principle valued at the closing rate and long-term assets at the historical rate, unless a lower going-concern value applies. Those rules govern the translation of a whole balance sheet, not the fate of a dollar receivable in euro-denominated accounts.

Which exchange rate should be used, and what entries follow?

Luxembourg accounting law does not impose any source for exchange rates, but the Commission des normes comptables expects the rates used to be consistent with those published by the European Central Bank. The freedom, in other words, is about the source and not about the level.

At transaction date the reference practice distinguishes the direction of the flow: the buying rate for a receivable, the selling rate for a payable. The Commission des normes comptables does not, however, prohibit using the average rate of the transaction date, which is what most software does and the only workable option on a high volume of invoices. What matters is that the convention be written down and applied without exception.

On the entries themselves, the standard chart of accounts set by the grand-ducal regulation of 12 September 2019, applicable to financial years beginning on or after 1 January 2020, provides dedicated accounts for exchange losses and exchange gains, with a split according to whether the counterparty is an affiliated undertaking. The frequent error is not the account number: it is posting the difference to profit and loss without an identifiable balance sheet counterpart, which makes the restatement impossible to reverse at the next opening.

That leaves the notes, which are not a formality here. The accounting and valuation methods used are disclosed there, and that includes the translation approach and the treatment of exchange differences. The bill recasting Luxembourg accounting law, filed with the Chamber of Deputies in July 2023 and whose parliamentary file was still open in the first quarter of 2026, would spell out that disclosure duty. It has not been voted: the law in force remains that of 2002.

Which mistakes do we see most often on exchange differences?

Three mistakes recur in Luxembourg files involving exchange differences: changing translation approach from one year to the next, restating foreign currency bank balances without restating the matching receivables and payables, and distributing a result that still contains an unrealised gain.

The first is almost always unintentional. It happens when software or providers change: the new configuration applies its default method, nobody compares with the prior year, and the notes keep describing the old one. We regularly see that gap surface two financial years later, when a financial result that nothing in the business explains has to be accounted for.

The second comes from the convenience of statements. A foreign currency bank account restates itself effortlessly because the bank supplies the converted balance, whereas a foreign currency customer ledger requires extraction work. The file then shows an exchange difference on cash and none on the receivables that fed it, which is inconsistent under all three approaches.

The third is the costliest because it repairs badly. Once a dividend has been paid out of a profit that contained an unrealised gain, the correction runs through a decision to repay or a shareholder current account, and the following year carries the trace of it. Redoing a full year of translation and rebuilding the trail item by item takes hours, billed at the hourly rates published on our pricing page; settling the translation convention before the first foreign currency invoice costs no more than a page of notes.

Sources and verification

Written for Financial Services Luxembourg and reviewed before publication by Mickaël LOC, authorised accountant (authorisation 10077274). Legal references, valuation principles and translation rules verified on 16 October 2026 against the official sources below.

From the Commission des normes comptables, Q&A CNC 22/027 on the accounting treatment of transactions and balances denominated in foreign currencies under the LUX GAAP and LUX GAAP-FV regimes, for the three accepted translation approaches, for restating current assets at the lower and liabilities at the higher of the two values under the classic approach, for restating monetary items at the closing rate under the monetary approach, for the absence of exchange differences on non-monetary items, for treating foreign currency bank balances as realised differences, for the buying rate on receivables and the selling rate on payables together with the admission of the average rate of the day, for the consistency expected with European Central Bank rates, and for the undistributable character of an unrealised exchange gain.

From Legilux and Guichet.lu, the amended law of 19 December 2002, for the prudence principle and the rule that only profits actually realised at the balance sheet date may be included in it, for the permanence of accounting and valuation methods, for the separate valuation of asset and liability items, for the disclosure of the methods used in the notes, and for the regime of the non-distributable reserve for unrealised income and gains net of tax, its prohibited uses and its release as the gains are realised.

From the Administration des contributions directes, the coordinated text of the amended law of 4 December 1967 in force on 1 January 2026, for article 40 and the carry-over of the commercial balance sheet only where the tax rules fix no amount, for article 23 and the carrying of assets at acquisition or production cost with the option of a lower going-concern value, and for the paragraph of that same article valuing debts by appropriate application of the preceding provision;

the thematic guidance on the valuation of assets belonging to the net invested assets of a commercial undertaking, for carrying debts at acquisition cost and using the going-concern value only where it is higher; circular L.G.-A no. 60, for translating a balance sheet kept in a foreign currency, the European Central Bank rates and the distinction between short-term assets at the closing rate and long-term assets at the historical rate.

From the accounting regulatory framework, the grand-ducal regulation of 12 September 2019 setting the content of the standard chart of accounts, applicable to financial years beginning on or after 1 January 2020. From parliamentary file 8286, the bill recasting Luxembourg accounting law filed on 28 July 2023 and its consolidated file still open in the first quarter of 2026.

Four points could not be verified against an official source at this date, the PDF documents being unreachable from this environment and the texts having been read through search extracts only. First, the full wording of Q&A CNC 22/027: the treatment of a long-term item under the short-term versus long-term approach was not read directly and is inferred here by contrast with the short-term rule, as the table caption states.

Second, the account numbers for exchange losses and gains in the standard chart of accounts, taken from a form preview predating the final version, which is why the article quotes none. Third, the exact scope of the reference to exchange variations in the fair value provisions of the 2002 law, whose consolidated text was read only in part. Fourth, the absence of a circular addressing expressly the tax treatment of a booked unrealised exchange gain: the consequence set out above is a reading of articles 23 and 40, not a published administrative position.

These points can be checked in the full Q&A on cnc.lu, in the consolidated 2002 law and the annex to the 2019 regulation on legilux.public.lu, and in the coordinated text of the 1967 law on impotsdirects.public.lu.

This article states the law as it stands at the date of publication and is not personalised accounting or tax advice: the treatment of an exchange difference depends on the translation approach the company has adopted, on how each item is classified and on the documentation supporting the rate convention. Principles, thresholds and texts change, and any decision binding your structure should be checked on the date you rely on it. Report an error to contact@financialservices.lu: the correction is dated in the article.