Recent data show that the use of credit cards in Canada has been increasing, while the use of cash has been declining. At the same time, only two-thirds of small or medium-sized businesses accept credit cards. To better understand future development of this trend, it is important to study whether a change in merchant fees will increase credit card acceptance and will thus further reduce cash use. In this note, we calculate the level of the merchant fee where a merchant would be indifferent to accepting a credit card or cash payment, using the merchant indifference test. We find that the results are sensitive to the underlying assumptions. Furthermore, we discuss several main issues of applying such a methodology to Canada.