the means used to read this stripe as discussed further below however some cards that will be desired to be used in card holder 10 do not have an inherent magnetic stripe so a separate tape or stripe provided with card holder 10 will be required for identification code 30 another possibility is to use strips of variably conductive material in conjunction with miniature contact switches to 34 read 34 these strips a card reader means is used to read identification code 30 and in the preferred embodiment this includes a magnetically sensitive transistor such as a field effect transistor fet 32 or a hall effect transistor het or some other transistor that can be physically incorporated into card holder 10 for the purposes of this specification the term fet is intended to include generically all such types of transistors one fet 32 is associated with each credit card 16 and fets 32 are connected to respective pin receptacles 34 which receive pins not shown mounted in top 12 to electrically connect fets 32 to the electronic circuitry in top 12 a card presence switch 36 is associated with each card 16 switches 36 are electrically connected to pin receptacles 38 which receive pins not shown mounted in top 12 to electrically connect.