Invoices: exchange rates.
In case of invoices issued after the supply of goods or services / receiving the prepayment taxpayer shall apply the average exchange rate of the National Bank of Poland from the last business day preceding the date of supply of goods or services / receiving the prepayment. In case of invoices issued before the supply of goods or services / receiving the prepayment taxpayer shall apply the average exchange rate of the National Bank of Poland from the last business day preceding the date of invoice.