Accounts · The books

Their currency
on the invoice.

Raise documents in the currency your customer actually pays in, while the ledger, the reports and the returns stay in yours. There is no second instance to run and no separate set of books to keep in step.

The usual workaround is a second company. Which then has to be consolidated by hand, every month, forever.

On the document

The currency, and the rate that applied.

Bill in their currencyInvoices, bills, purchase orders and journals can each carry a currency other than yours.
The rate is capturedHeld against the document, so what you reported is what the rate was that day — not what it drifted to afterwards.
In the books

One chart, one set of reports.

No second instanceOne tenant, one chart of accounts, one trial balance. Foreign-currency documents post into it rather than beside it.
Reports in your currencyThe P&L and balance sheet stay in your reporting currency, whatever the underlying documents were raised in.
The return is unaffectedGST is computed in your own currency from the converted values, so selling abroad does not complicate the filing.
Which documents

Both sides carry a currency.

Not only sales. A business that exports usually imports too.

Customer invoices and proformasQuote and bill an overseas customer in what they will actually pay.
Vendor bills and purchase ordersRecord an import in the currency the supplier invoiced, rather than converting on the way in and losing the original.
The original is keptThe document retains what was billed and in what currency, so a later dispute is about the same numbers both parties are holding.
Nearby

Related capabilities.

Invoicing · General ledger · Financial reports

Sell abroad without a second set of books.

The currency lives on the document. The ledger stays yours.