bankDetails required for a Payee depend on the currency and the type of payment you want to make to the Payee.
Supported Payment Schemes
UK Faster Payments -
SEPA Credit Transfer -
When a Payee is created, the response contains a
paymentSchemes param which tells you the Payment Schemes via which the created Payee can be sent a payment.
"paymentSchemes":[ "FPS", "CHAPS" ]
"paymentSchemes":[ "SCT" ]