Techniques for making electronic cards that can be displayed on a mobile phone. The techniques permit making an electronic card based on an arbitrary SMS message and making an electronic card (eCard) that corresponds to a pre-existing non-electronic privilege card such as a loyalty card. In the latter case, the system on which the card is being made obtains information about the user and the issuer and uses the information to determine whether to issue the eCard and also to make use validity information which is associated with the card and is used to determine the validity of the card as it is used.