Flash cards are associated with debit or credit card accounts. If it is a debit card, after you deposit the amount in the debit card, the amount in the debit card will be reduced accordingly. Anyway, it doesn't matter if you don't pay back your money. If it is a credit card, the amount will be reduced. Even if you don't use flash card, the reduced amount of credit card will still be paid back when it expires, although you didn't pay in flash to avoid overdue.