A system and method for using write-and-destroy transaction cards which cannot be reprogrammed. The write-and-destroy transaction cards are programmed (i.e., written to) at bit increments representing, in total, the stated value of the card. The stated value may be represented in one or a plurality of denominations and currencies. In use, the remaining value of a card can be ascertained at a merchant location by reading those bits which have not been erased. The remaining value can additionally be confirmed by contacting the issuing financial institution using a unique serial number which may be encoded onto each transaction card. Upon confirmation that the card has sufficient value to conduct the desired transaction, the card is decremented by erasure of the bits representing that value. By invocation of locally stored software, or based upon communication with a host location, the current rate of currency exchange between the merchant-preferred currency and the currency represented at bit increments on the transaction card can be ascertained and the appropriate value decremented by erasure from the card. Once bits have been erased, they cannot be reprogrammed.