We designed the core of the billing platform to be internationalized. The catalog module has support for all currencies, including crypto-currencies (e.g. Bitcoin). The invoice module will understand these various currencies and respect localization rules. (For example, it will correctly round US dollars to two decimal places but Japanese Yen amounts will have no decimal portion.)
Accounts can have a designated locale (for example, $1,234.99 will be displayed as 1.234,99 $ for accounts with the French Canada locale) and a time zone (to generate invoices in their time zone instead of the merchant’s).
From a payment perspective, Kill Bill supports payment gateways via plugins. If your international gateway isn’t supported yet, you can simply write a plugin for it.
Note: If your organization or development team needs help writing a plugin, we can recommend partners that have created them before for Kill Bill users. Check out one of our partners here.