According to Mankiw (2018):

. . . credit cards are excluded from all measures of the quantity of money. The reason is that credit cards are not really a method of payment but rather a method of deferring payment. When you buy a meal with a credit card, the bank that issued the card pays the restaurant what it is due. At a later date, you will have to repay the bank (perhaps with interest). When the time comes to pay your credit card bill, you will probably do so by writing a check [or an electronic transfer] against your checking account. (p. 609)

Again, when you use a credit card, you are actually taking out a loan from the bank. When you buy something with a credit card, your bank pays the merchant with electronic transfers of US dollars or, if you buy something in another country, then your bank pays the merchant with foreign currency, and then your bank grants you a loan.

Which of the three defining characteristics of money do not apply to credit cards? Why?