The two most common issues with multi-currency quotations are: first, exchange rates don't update in time, and the quoted price has already incurred a loss by settlement; second, when invoicing at shipment, you need to convert to your home currency for accounting, and if the commercial invoice currency differs from internal accounting currency, conversion errors easily cause account mismatches. The practical approach is to lock in the exchange rate validity period when quoting and clearly indicate the currency and rate on both the proforma invoice (PI) and commercial invoice. On the system side, what helps is automatically performing exchange rate conversion when issuing a commercial invoice, and allowing additional charges (such as handling fees or currency adjustment fees), so that accounting figures can be reconciled with actual receipts.