Is it permissible to use a treatment project card for a sister after the inquirer's card balance runs out, especially since the card does not explicitly prohibit this?

It is not permissible for anyone to use another person's card, as this involves lying, forgery, and consuming wealth unlawfully. It does not matter that the card does not explicitly state a prohibition against its use by others, or that the father paid the subscriptions, for each card has its own balance and specific limit. Whether the insurance is cooperative or commercial, it is necessary to fulfill its conditions and not to circumvent them. Circumvention also includes the employee who knows about it and approves of it.