Navigation:  Settings > Base Currency

If your business manages accounts in multiple currencies, the first step in enabling multi-currency is to set your base currency under Settings tab, then Base Currency.

Once you set your base currency, all your existing accounts will be set to be denominated in base currency. When you edit your existing accounts or create new accounts, you will have an option to select in which currency the account should be denominated.

Currently it's possible to set foreign currency on following accounts:

When it comes to transactions, most transactions will inherit currency from account they relate to. For example, when you set foreign currency on customer, all their invoices, credit notes or quotes will be denominated in that foreign currency.

Some transactions such as journal entries or expense claims allow you to specify foreign currency on transaction level. For example in case of expense claims, this is useful when employee is being always reimbursed in base currency but have expense claims paid in foreign currency.