What it means
A set of accounts can only add up if every figure is expressed in the same unit. The accounting currency, sometimes called the reporting currency, is that unit, and it is usually the currency of the country where the business is registered or where most of its cash flows arise.
A related idea is the functional currency, which is the currency of the main economic environment a business actually operates in. Most small firms never think about this because they buy, sell, borrow and pay tax in one currency.
The question becomes real as soon as a business imports stock, sells abroad, holds a foreign bank account or owns a subsidiary in another country. At that point every foreign transaction has to be translated into the accounting currency at a defined exchange rate.
The general approach is straightforward in outline. Transactions are recorded at the rate on the day they happen, monetary balances such as foreign cash, receivables and payables are retranslated at the closing rate on the balance sheet date, and the resulting differences are recognised as exchange gains or losses.
The nuance that catches people out is the difference between realised and unrealised movements. A gain on an invoice you have actually collected is realised cash; a gain from retranslating an unpaid invoice at year end is only an accounting adjustment that may reverse next month.
Both hit profit, but only one of them is money in the bank. Group reporting adds a further layer.
A subsidiary keeps its own books in its local functional currency, and those figures are then translated into the parent's accounting currency for consolidation, with the differences parked in a separate reserve within equity rather than run through profit. That is why a group can report a lower net asset figure purely because a currency moved.
In practice
Real-world examples.
Example
A furniture retailer reporting in dollars buys container loads from two European suppliers. Each invoice is converted at the rate on the shipping date, and when the euro strengthens before payment, the extra dollars needed show up as a realised exchange loss rather than a higher cost of goods.
Example
A consultancy reporting in dollars wins a large contract billed in Japanese yen and holds a yen bank account to receive it. At year end the yen balance is retranslated at the closing rate, producing an unrealised gain of $18,000 that the finance director carefully flags to the board as reversible.
Example
A group with a Canadian subsidiary consolidates in dollars. The subsidiary's trading is flat in Canadian dollars, but a 6% currency move means its contribution to group revenue falls, so management reports both the reported figure and a constant currency figure to show what really happened.
Formula
Calculation
Amount in accounting currency = amount in foreign currency x exchange rate
Exchange difference = amount at closing rate - amount at the rate originally recorded
A US parent company reports in dollars and owns a subsidiary that keeps its books in Mexican pesos. At the point of the transaction, the subsidiary holds a receivable of 2,400,000 pesos and the rate is 0.05 dollars per peso.
Recorded value = 2,400,000 x 0.05 = $120,000.
By the balance sheet date the peso has weakened and the closing rate is 0.048 dollars per peso.
Retranslated value = 2,400,000 x 0.048 = $115,200.
Exchange difference = $115,200 - $120,000 = -$4,800, an unrealised loss. The receivable is still 2,400,000 pesos and the customer still owes exactly what it always did, but in the accounting currency the asset is $4,800 smaller and reported profit falls by the same amount.Case study
Seen in the real world.
The following is an illustrative and entirely fictional example. Northgate Instruments, an invented scientific equipment distributor, reported in dollars while sourcing almost all of its stock from a single overseas manufacturer. For three years the exchange rate barely moved, so nobody in the business paid the accounting currency question any attention.
In its fourth year the supplier's currency strengthened by roughly 8% between order and payment on most shipments. Purchases recorded at one rate were settled at a worse one, and the fictional company booked $214,000 of realised exchange losses across the year, turning a $180,000 operating profit into a reported loss.
The board's first instinct was to blame pricing, but the analysis showed gross margin on each unit was unchanged in the supplier's currency. The response was practical rather than accounting driven: the company began agreeing forward rates for large orders and quoting customers with a currency adjustment clause, which stabilised reported profit without changing the underlying business at all.
Watch out
Common mistakes.
- Converting foreign transactions at whatever rate is convenient on the day the bookkeeping is done, rather than the rate on the transaction date.
- Treating unrealised exchange gains as spendable profit, when they can reverse entirely before the underlying balance is ever settled.
- Assuming the accounting currency must be the currency of the country of registration, when the functional currency should reflect where the real cash flows arise.
Questions
People also ask.
What is the difference between functional currency and presentation currency?
The functional currency is the one the business genuinely operates in, while the presentation currency is the one chosen for the published statements, and a group may translate from the first into the second.
Can a company change its accounting currency?
Yes, but only when the underlying economics genuinely change, and the change is applied from that date forward with clear disclosure rather than being applied retrospectively.
Where do translation differences on a foreign subsidiary go?
They are usually taken to a separate translation reserve within equity rather than through profit, because they arise from consolidating a whole business rather than settling a single transaction.
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