In the Business Central UI, it is possible for the user to override the currency exchange rate used for sales or purchase invoices/credits.
However, the REST API does not seem to allow the currency exchange rate to be submitted for a new sales or purchase invoice/credit. The REST API does accept the foreign currency amounts and a currency code, but specifically does not accept an exchange rate.
Please add a feature to allow an external application to create new foreign currency sales or purchase invoices/credits whilst also supplying the currency exchange rate for an invoice/credit in the payload. This is required to avoid potential differences of base currency amounts between an external application and Business Central.
Many thanks for your attention.
Business Central Team (administrator)
Thank you for this suggestion! Currently this is not on our roadmap. We are tracking this idea and if it gathers more votes and comments we will consider it in the future. Best regards, Business Central Team