If the customer’s currency has not yet been set, Stripe will default to showing your account’s default settlement currency when creating an invoice in the dashboard.
If a customer's currency has already been set, Stripe will default to showing that currency when creating an invoice in the dashboard.
You can change the customer's default currency if there are no active subscriptions, quotes or other Billing objects in the customer's current currency. The customer's default currency will be changed when the customer does not have any active subscriptions and you start a new subscription, quote or subscription schedule for the customer in a new currency.
If a customer has any ongoing subscriptions, you can cancel existing subscriptions and re-create them in a different currency to change the customer's default currency. The currency cannot be updated on an ongoing subscription.
You can create one-off invoices in a currency that's different than the customer's default currency. This feature is available both in Invoices API and in the dashboard for one-off invoices. It is not supported in subscriptions currently.