Recording foreign currencies in bookkeeping

The basic rule

In Swiss accounting, all transactions must be recorded in Swiss francs (CHF). If you invoice in EUR or USD, you need to convert the amount to CHF at the time of the transaction.

Which exchange rate to use

The Federal Tax Administration publishes monthly average exchange rates. You can use these or the actual daily rate from your bank. Important: be consistent. Don't switch between monthly averages and daily rates — the tax office will ask questions.

Currency gains and losses

When you issue an invoice in EUR and by the time the client pays, the EUR/CHF rate has changed, you realize a currency gain or loss. Example: you invoice EUR 1,000 when the rate is 0.95, so you record CHF 950. The client pays when the rate is 0.93 — you receive CHF 930. The CHF 20 difference is a currency loss and is tax-deductible.

Practical approach for sole proprietorships

For simplicity: record income at the rate on the day the invoice is issued. When the payment arrives, record any difference as a currency gain or loss in a separate category. This keeps your books clean and gives the tax office exactly what they need.

How MILQ does it

Foreign currencies are a feature you switch on when you need it — most sole proprietorships only book in francs and never see it. Switch it on under Settings › Features › “Foreign currencies EUR, USD and GBP”.

Recording: pick the currency in the entry form and type the amount as it appears on the receipt. When a receipt is scanned, MILQ detects the currency itself. Converting: MILQ fetches the official FTA daily rate for the booking date and converts to francs; if the date falls on a weekend, the last published rate applies. If you prefer the rate from your bank statement, you overwrite it — the entry remembers whether the rate came from the FTA or was entered by hand.

Documenting: journal, account detail and CSV export show the original amount, the rate and its source for every foreign-currency entry — exactly the documentation an audit asks for. Invoices remain in francs: the conversion applies to income and expenses in the journal. For customers in the euro area, an invoice in CHF with a QR payment part is unproblematic in practice.