Functional currency vs transaction currency.
growing SMBs operate in $as functional currency: the currency of the primary economic environment. Transactions in any other currency (USD, EUR, GBP, AED) are foreign currency transactions. The principle is simple: every foreign currency transaction is recorded in $using the spot exchange rate on the transaction date. Subsequent settlements at different rates create exchange gains or losses that flow through the P&L.
The most common growing SMB cases are USD invoices to US clients (export of services or goods), EUR invoices to European clients, USD payments to overseas suppliers, and-USD foreign currency accounts (held at HBL or Standard Chartered). All four cases follow the same accounting principle: convert to $at the right rate, recognize differences as they arise, revalue monthly.
The transaction date rate and the settlement rate.
When you raise a USD 10,000 invoice on March 15 at the spot rate of $280: DR Accounts Receivable USD - Customer X 2,800,000 (in $equivalent) / CR Sales 2,800,000. The receivable is denominated in USD but recorded in $at the day-one rate.
When the customer pays USD 10,000 on May 20 at the spot rate of 287: $equivalent of USD 10,000 received is 2,870,000. Entry: DR Bank 2,870,000 / CR Accounts Receivable 2,800,000 / CR Exchange Gain 70,000. The exchange gain of $70,000 is real income, taxable, posted to other income or finance income depending on your COA. If the rate had moved the other way (down to 275), you would have an exchange loss of $50,000 instead.
Monthly revaluation of foreign currency balances.
Receivables, payables, bank balances in foreign currency are revalued at month-end at the closing rate. USD 10,000 receivable booked at 280 ($2,800,000) is still outstanding on March 31 when the closing rate is 282. Revalue: USD 10,000 x 282 = $2,820,000. Adjustment: DR Accounts Receivable 20,000 / CR Unrealized Exchange Gain 20,000. The $balance now matches the underlying USD balance at the current rate.
On April 30 if the rate is 285, further adjustment: USD 10,000 x 285 = 2,850,000, current balance 2,820,000, adjustment of $30,000 to unrealized gain. When the customer ultimately pays in May at 287, the actual gain is $70,000 cumulatively, of which 50,000 was already taken as unrealized in March and April, and 20,000 is realized in May. Net P&L impact across the period is correct; timing reflects when rates moved.
Foreign currency bank accounts.
A USD account at HBL holding USD 50,000 is a foreign currency asset. The $equivalent fluctuates daily with the rate. At each month end, revalue the-equivalent balance at the closing rate. USD 50,000 was 14,000,000 at March 31 (rate 280), and is 14,250,000 at April 30 (rate 285). Adjustment: DR Bank USD 250,000 / CR Unrealized Exchange Gain 250,000.
The complication: which rate? The State Bank of publishes a daily rate. Most banks have their own buying and selling rates. A common policy is the SBP middle rate for revaluation and the bank's applicable rate for actual conversions. Document your policy and apply it consistently. Auditors check.
Hedging and forward contracts.
Some SMBs with significant USD exposure book forward contracts to lock in a rate. A six-month forward to sell USD 100,000 at 290 hedges the receivable. Accounting for forward contracts is more complex (mark-to-market, ineffectiveness testing under IFRS 9 or similar). For most SMBs, hedging is not done, and exposure is simply lived with as exchange gain or loss in the P&L.
The risk is real. $has weakened against USD in many recent years, which has been positive for exporters and negative for importers. Tracking exchange impact monthly helps quantify the natural hedge or exposure your business has. With Nonari you see the cumulative $impact of FX movement on receivables, payables, and FX bank balances on one screen.
Tax treatment of exchange gains and losses.
Realized exchange gains are taxable income; realized exchange losses are deductible expenses. Section 67 of the your country’s tax code addresses this. For unrealized exchange differences (revaluations of monetary items at year end), tax practice generally accepts them as taxable or deductible, but some authorities argue they should be deferred until realized. Get a professional opinion for material amounts.
For sales tax, the rate at the date of supply determines the sales tax payable. Subsequent exchange differences do not change sales tax. So if you invoiced USD 10,000 plus 17% sales tax to a customer in Atlanta (export-related complexities aside), the 17% is fixed in $at the date-of-supply rate. Exchange differences thereafter are income tax matters only.
Common errors in FX accounting.
Error one: using the same rate for invoice and payment. Easy on Excel, wrong in reality. The rate moves; the books must reflect that. Error two: forgetting to revalue at month-end, then booking a huge realized gain or loss whenever the customer pays. P&L becomes lumpy and uninformative. Error three: revaluing income statement items (revenue, expenses) at month-end. Only monetary balance sheet items get revalued; revenue and expenses stay at their transaction-date rates.
Error four: using the wrong rate (bank buying when you should use bank selling, or middle rate when you should use applicable). Document your rate source and stick to it. Error five: posting FX differences to Sales or COGS instead of a dedicated Exchange Gain/Loss account. This pollutes gross margin analysis. Always use specific FX accounts so P&L analysis stays clean.
- Record at transaction-date rate.
- Revalue monetary items at closing rate monthly.
- Realized vs unrealized: book both with separate accounts.
- Income statement items stay at transaction rate.
- Document the rate source and apply consistently.
A worked example, six-month engagement.
A software firm invoices a US client USD 50,000 on January 10 at rate 278 ($13,900,000). Client pays on June 15 at rate 286. Monthly closing rates: Jan 280, Feb 281, Mar 283, Apr 284, May 285, June 286.
January end revaluation: USD 50k x 280 = 14,000,000, originally 13,900,000, gain $100,000 unrealized. Each subsequent month revalues to closing rate: Feb +50k, Mar +100k, Apr +50k, May +50k. Cumulative unrealized gain by May 31: $350,000. June 15 payment: cash received $14,300,000, original receivable 13,900,000, total realized gain $400,000, of which 350,000 was already unrealized and 50,000 is incremental this month.
Each month's P&L reflects the exchange impact of that month, not a single lumpy gain in June. With Nonari, all this is automated; you set the rate source once and monthly revaluations post on close.