A A banknote (or ‘bill’ as it is often referred to in the US) is a type of negotiable promissory note, issued by a bank or other licensed authority, payable to the bearer on demand. declared worthless as a medium of The Eurosystem comprises the European Central Bank and the national central banks of those countries that have adopted the euro. or as Money that is legally valid for the payment of debts and must be accepted for that purpose when offered. Each jurisdiction determines what is legal tender, but essentially it is anything which when offered (“tendered”) in payment of a debt extinguishes the debt. There is no obligation on the creditor to accept the tendered payment, but the act of tendering the payment in legal tender discharges the debt.. See Legal tender.