Definicija: The currency a business uses to record all transactions in their ledgers, or the primary currency in which they transact with their bank. The base currency is also commonly referred to as the billing currency, functional currency, or booking currency of a business. The Order Processing pipeline always processes orders using the base currency of the Web site. The base currency can be different than the buyer currency and the supplier currency. The base currency is stored in the billing_currency field in the orderform header.