This is lightened version of the eligibility omitting some customer's data (birth date, birth zip code, birth name).
The pre-eligibility should be called before "payment method choices" page to display only payment methods on which the customer is eligibible for.
This allows to fluidize the customer's experience and avoid his potential frustration when refused during payment.
The list of merchant site identifiers allows to call the service once for multiple payment type.
The pre-eligibility returns a request id which will allow to link the pre-eligibility to the eligibility during eligibility request.