Visa Interchange Reimbursement Fees and Merchant Rules
Visa
Visa's published page on US interchange reimbursement fees, with the official fee tables (PDF) by card type and transaction category, plus merchant surcharging requirements, sample disclosure signage, and a link to the Visa Rules. Lets a learner check real interchange rates, including card-not-present categories that apply to online sales, instead of relying on secondhand estimates.
More resources on Payment Gateways
PayPal Developer
PayPal's official developer portal with API reference, SDKs, integration guides, and a sandbox for testing. Developers learn to add PayPal Checkout, process orders and refunds, handle webhooks, and test payment flows with sandbox accounts before going live.
Payments on Fire
Long-running podcast from payments consultancy Glenbrook Partners, with over 300 episodes. Hosts and industry guests discuss card acceptance, authorization rates, subscription payments, network rules, agentic commerce, regulation and the business of payment companies.
PCI SSC Merchant Resources
Official PCI Security Standards Council guidance for merchants accepting cards. Includes the Guide to Safe Payments, common payment system diagrams, questions to ask vendors, and FAQs on who must comply, self-assessment questionnaires, and how encryption affects PCI DSS scope.
How credit cards make money
Essay on the revenue model of credit cards: net interest, interchange, fees and network marketing contributions. Explains what interchange is, why merchants pay it, how it is split among issuer, processor, acquirer and network, and how regulation changes it.
Payments Systems in the U.S.: A Guide for the Payments Professional (3rd Edition)
Structural anchor for the topic: explains what a gateway actually connects to (acquirer, network, issuer) and who earns what. Reference text covering how US payment systems operate: card networks, the four-party model, issuers, acquirers, processors, authorization, clearing and settlement, ACH, wires and checks. Explains each system's economics and rules, and the third edition adds a chapter on payments innovation and a glossary.
stripe.com
Stripe is a payments platform offering API-based online payment processing, subscriptions, and related financial tools for businesses. Its site provides developer documentation, API references, integration guides, checkout components, pricing, and tutorials to learn how to implement and optimize payment gateways.