An item can only have one cost currency.

An item can have multiple sales (price) currencies.

When an item is added to a quotation set with a different currency, the cost is converted to the quotation's currency.

If the item has a price in the quotation's currency, it will use that price.

If there is no currency price, it will convert automatically to the quotation currency if the exchange rate is in the system.

For currency conversion to work, the rates must be set up in Cog -> Exchange Rates. If the same currency pair is in twice but mirrored (i.e. GBP->USD and USD->GBP, it will use the one that matches the conversion (i.e. a cost in GBP on a USD quotation will use GBP->USD). This means a rate spread can be used.

When prices are refreshed on the quotation, they will be converted at the rate for that currency pair in the system.

When the currency dropdown's value is changed, no calculations are applied. Use the Refresh Prices on the Apply button to update them.