Create a cardholder

Registers a cardholder for a customer and submits it to the card issuer for review in the background. The response has status: pending; get the result from GET /cardholders/{cardholderId} or the cardholder.status_changed webhook. When the issuer does not need cardholders and only the product's application conditions require one, the cardholder is registered in UPP only and returned as approved.

• The customer must already have an approved verification of the product's cardholder_verification_usage usage (default basic). Name, ID document and photos come from that verification and are not sent in the request.
• When the product has requirements (cardholder_requirement_id is not null), field names are the issuer's field names (they may contain dots, such as kycVerification.referenceId; use them as-is as keys in fields, do not nest them). customer_id is optional, in which case the cardholder is not linked to a customer. The issuer decides whether a customer verification is needed and which fields the customer or verification can supply: when linked to a customer, name, ID document and photos usually come from the customer's verification and submitted values do not override it; when not linked, fill in cardholder_fields, using file IDs from the Files API for fields of type file. Cardholders registered only in UPP are validated against cardholder_fields only.
• See the product's cardholder_fields for fields and formats. Only fields the product requires are stored; extra fields are ignored. Validation error keys are fields.<field name>.
• A customer can have only one cardholder that has not failed per card product.