Checks whether a name matches the account held at the receiving bank before you pay it. clientId is required and must be a client this credential may act for. GB sort-code and account-number details are checked through the UK Confirmation of Payee scheme; IBAN-based checks through the SEPA Verification of Payee scheme are planned. Returns the outcome (answer, the actual name where disclosed, reason code) and an id to pass as accountNameVerificationId when creating a GB sort-code payee.