If you have a customer invoice (CIN) in status 1 for a customer set up with more than 1 currency it is possible to change the currency on a customer invoice (CIN) for this customer even if there is an item registered on the document.  The currency field will have dots "...." and an arrow where you can choose the required currency.
The amount of each item and the total amount will be converted to the amount in the currency you select.


Nb! If you change the  currency (CUR) on a customer invoice (CIN) coming from a customer credit note (CCN) the currency and the amounts on each customer invoice (CIN) item are recalculated.

If you change the currency (CUR) on a customer invoice (CIN) coming from a customer shipping advise (CSA) only the currency is changed. The amounts on the respective customer invoice (CIN) item are not recalculated.