It is possible to bind a tokenized card to a buyer when it is being created. There are a few ways to do so.
The easiest way to associate a buyer to a card is to pass along a
when creating a card.
This will find a buyer with that
id and associate the card to it. If a buyer
id could not be found it's ignored.
Alternatively, a card can be associated to a buyer by it's
external_identifier. If a buyer with that
external_identifier could not be
found it's ignored.