When Apple insists on its cut from Apple Pay transactions, it's not kidding. According to details from a leaked copy of the contract, Apple can request a written certification that the amounts are accurate and if they dispute it, they get to hire an auditor. If that auditor proves an underpayment exceeding 5 percent, the issuer has to pay for that audit.

Details of the 19-page Apple Pay contract between it and its issuer detail that beyond the 0.15 percent of the transaction amount that has been widely reported, Apple is also getting a half-penny for every debit transaction. Issuers must make available for Apple Pay at least 95 percent of the cards in their portfolios that are branded by a participating network, such as Visa or MasterCard. The agreement specifies certain types of cards issuers may be excluded from this calculation, including ATM-only cards, gift cards, health-savings-account cards, and commercial cards.

These fees paid to Apple are in addition to those now assessed by the networks to tokenize cards. For instance, MasterCard is charging 50 cents to provision each token, and it has been reported that Visa charges issuers 7 cents and 2 cents if a token is declined.

The contract is said to detail the flow of monies which is interesting. "Issuers pay the card network, which will then pass the fees on to Apple, according to the contract terms. Issuers will receive an invoice each month from the network and will have 15 business days to pay it.

The paperwork burden, as described, is onerous. Issuers must report “an extensive set of statistics” related to Apple Pay activity, including nearly 36 different categories, it is reported. Data including number and dollar volume of credit and debit activity, average ticket, breakdown of transactions between in-store and in-app usage, and top 100 merchants by charge volume are all examples of what Apple is interested in seeing.

A report from financial analyst firm Keefe, Bruyette & Woods said the level of control that the major card brands is interesting. "Aside from the differences in fees Apple receives on debit vs. credit transactions, which we suspected might have been the case due to the differential in interchange between the two products, the other most relevant incremental data point comes from how close the relationship the between the networks and Apple appears to be. Visa and MasterCard, beyond the security aspect of tokenization, seem to be playing a large operational role," wrote Sanjay Sakhrani, a managing director at the firm.

This all illustrates the power of Apple Pay.