Payments Processing: The Largest Revenue Pool in Financial Services

Introduction

Payments is the single largest revenue pool in financial services, generating $2.4 trillion in global revenue in 2023 and projected to exceed $3 trillion by 2028. No other financial services category (not commercial banking net interest income, not insurance premiums, not asset management fees) produces revenue of this magnitude. Payments is also the most diversified category: it spans consumer point-of-sale transactions, e-commerce checkout, B2B invoicing, cross-border remittances, real-time transfers, and embedded payment functionality within platforms. For FIG bankers, payments generates deal flow through M&A (acquirer consolidation, network expansions, fintech acquisitions), capital markets (payments company IPOs and secondary offerings), and strategic advisory (bank-fintech partnerships, cross-border expansion, regulatory strategy).

The payments ecosystem is structured around a hierarchy of participants, each earning a slice of every transaction. Understanding who earns what, and why, is essential for analyzing payments company valuations, competitive dynamics, and the regulatory forces that threaten to reshape the economics.

The dominant structure for card-based payments worldwide is the four-party model (sometimes called the open-loop model), which involves four participants in every transaction:

Cardholder: the consumer (or business) making a purchase with a credit or debit card issued by their bank.

Issuer: the bank or financial institution that issues the card to the consumer (JPMorgan Chase, Bank of America, Citigroup, Capital One). The issuer extends credit (for credit cards) or debits funds (for debit cards), assumes fraud and credit risk, and earns interchange fees plus interest income on revolving balances.

Card network: Visa, Mastercard, or (for certain domestic markets) UnionPay, JCB, or RuPay. The network operates the rails that connect issuers and acquirers, sets interchange rates, enforces brand standards, and earns network assessment fees on every transaction that flows through its system. Critically, networks do not lend money, take credit risk, or hold consumer deposits.

Acquirer/merchant: the acquirer (also called the merchant acquirer or payment processor) contracts with the merchant, provides the point-of-sale terminal or payment gateway, routes the transaction to the network, and settles funds to the merchant's bank account. The acquirer earns the merchant discount rate (MDR), from which it pays interchange to the issuer and network fees to Visa/Mastercard, retaining the remainder as its margin.

The Merchant Service Charge (MSC) Breakdown

When a consumer pays $100 with a credit card, the merchant does not receive $100. The merchant pays the merchant service charge, which is distributed among the four-party participants:

On that $100 transaction, the merchant might pay $2.50 in total fees: $1.80 in interchange (to the issuer), $0.14 in network fees (to Visa/Mastercard), and $0.56 to the acquirer/processor. This fee structure explains why interchange is the dominant revenue component, why issuers invest heavily in rewards programs (funded by interchange), and why merchants have lobbied aggressively for interchange regulation (the Durbin Amendment capped debit interchange at approximately 22 cents per transaction for large issuers).

Interchange Fee

The fee paid by the merchant's acquirer to the cardholder's issuing bank on every card transaction. Interchange is set by the card networks (Visa, Mastercard) but paid between the acquirer and issuer, making it a "transfer price" within the four-party system. Interchange rates vary by card type (credit vs. debit), merchant category (grocery, fuel, e-commerce), card tier (basic, rewards, premium), and region. In the US, credit card interchange averages approximately 2.0-2.2% of transaction value, while regulated debit interchange is capped at approximately 22 cents per transaction under the Durbin Amendment. Interchange is the largest single component of the merchant service charge and the primary revenue source for card-issuing banks. In 2024, US interchange fees totaled an estimated $170+ billion, with approximately 86% of interchange revenue funding cardholder rewards programs according to Federal Reserve data. For FIG analysts, interchange is the economic engine that drives the card payments ecosystem: it funds issuer rewards (which drive card adoption), creates merchant acceptance costs (which drive demand for lower-cost alternatives), and generates regulatory attention (the Credit Card Competition Act and Durbin Amendment both target interchange economics).

Visa and Mastercard are the toll collectors of the global payments system. They operate the transaction routing infrastructure (the "rails") but do not issue cards, lend money, or take credit risk. This asset-light, network-effect business model produces extraordinary financial characteristics:

Visa processed $15.5 trillion in total payment and cash volume in FY 2024, generating $35.9 billion in net revenue (10.0% YoY growth) at approximately 40% net margins. Mastercard processed $9.7 trillion in gross dollar volume, generating $28.2 billion in net revenue (12.2% YoY growth). Together, these two networks facilitate the vast majority of global card transactions outside China (where UnionPay dominates).

Visa holds a 52.2% global credit card market share in 2025, with Mastercard at 21.6% and American Express at approximately 15%. Unlike Visa and Mastercard (which operate open-loop networks where any issuer can participate), American Express operates a closed-loop model: Amex is simultaneously the network, the issuer, and (in many cases) the acquirer, earning the full merchant discount rate rather than just the network fee.

Open-Loop vs. Closed-Loop Payment Networks

Open-loop networks (Visa, Mastercard) allow any bank to issue cards on the network and any acquirer to accept them. The network sets rules and interchange rates but does not directly interface with consumers or merchants. Revenue comes from network assessment fees (a small percentage of every transaction). Closed-loop networks (American Express, Discover) issue cards directly (or through limited partners), acquire merchants directly, and earn the full merchant discount rate. Closed-loop networks capture more revenue per transaction but face higher costs (credit risk, customer acquisition, merchant sales) and smaller acceptance footprints. Visa and Mastercard trade at premium multiples (25-30x+ forward earnings) because their open-loop model produces recurring, capital-light, high-margin revenue with minimal credit risk. Amex trades at lower multiples because its closed-loop model carries credit risk and higher operating costs, despite generating higher revenue per transaction.

Below the network layer sits the processing and acquiring infrastructure: companies that connect merchants to the card networks, route transactions, manage settlement, and provide value-added services (fraud detection, analytics, reconciliation, point-of-sale hardware).

Legacy Processors (Bank-Owned Heritage)

Fiserv (which acquired First Data in 2019 for $22 billion): the largest merchant acquirer and payment processor in the US, processing transactions for millions of merchants through its Clover point-of-sale platform and First Data acquiring business. Fiserv generated $20.7 billion in revenue in 2024.

FIS (Fidelity National Information Services): a major banking technology and payments processing company. FIS sold a 55% stake in its Worldpay merchant acquiring unit to GTCR in 2024 for approximately $18.5 billion, reflecting the strategic separation of banking technology from merchant acquiring.

Global Payments: a pure-play merchant acquirer and technology provider that merged with EVO Payments in 2023, generating approximately $9.6 billion in revenue.

Fintech Disruptors

Stripe: the dominant payment facilitator for internet commerce, processing payments for millions of businesses. Stripe reached $5.1 billion in net revenue in 2024 (up 27.8% YoY) and is valued at $106.7 billion as of September 2025, making it the most valuable private fintech company.

Block (Square): operates the Square merchant acquiring platform (focused on SMB and omnichannel commerce) and Cash App (a consumer finance super-app). Block is valued at approximately $37.2 billion.

Adyen: a Netherlands-based unified commerce platform serving enterprise merchants (Uber, Spotify, Microsoft). Adyen generated $2.16 billion in net revenue in 2024 and is valued at approximately $49.4 billion.

PayPal: the largest digital wallet by user base, with over 430 million active accounts. PayPal processes payments across e-commerce, peer-to-peer (Venmo), and in-store channels.

Understanding how revenue flows through the payments value chain is essential for valuation:

The payments value chain is characterized by volume leverage: networks, processors, and facilitators all have high fixed costs and low marginal costs per transaction, meaning that incremental volume flows directly to the bottom line. This explains why payments companies trade at premium multiples relative to other financial services: the operating leverage inherent in the business model produces expanding margins as payment volumes grow with GDP, e-commerce penetration, and the cash-to-digital transition.

Cross-Border Payments

Cross-border payments represent the highest-margin segment of the payments industry. When a US consumer purchases from a UK merchant, the transaction involves currency conversion, cross-border interchange (which is higher than domestic interchange), and network assessment fees that are 2-3x higher than domestic rates. Visa and Mastercard earn disproportionate revenue from cross-border volume, which is why international travel recovery post-pandemic was a major revenue catalyst. Cross-border payment revenue is estimated at $240+ billion annually, with fintechs like Wise (TransferWise) and Remitly competing with banks and networks for share.

Real-Time Payments

Real-time payment infrastructure (FedNow in the US, UPI in India, Pix in Brazil, Faster Payments in the UK) enables instant, 24/7 bank-to-bank transfers that bypass the card networks entirely. India's UPI processed over $2.4 trillion in transaction value in FY 2024 across 16+ billion monthly transactions, demonstrating how real-time payment rails can displace card-based payments in emerging markets. FedNow, launched in July 2023, is still in early adoption in the US but represents a long-term structural threat to card network dominance in certain use cases (bill payments, account-to-account transfers, payroll disbursement).

B2B Payments

The global B2B payments market was valued at $11.69 trillion in 2024 and is projected to reach $15.88 trillion by 2030 (5.2% CAGR). B2B payments remain heavily reliant on checks, wire transfers, and ACH in the US, with card penetration below 10%. The digitization of B2B payments (virtual cards, integrated payables, embedded payment functionality in ERP systems) represents one of the largest untapped growth opportunities in payments. Companies like Corpay (formerly FLEETCOR), Bill.com, and Bottomline Technologies are building infrastructure to capture this transition.

The European payments landscape operates under a fundamentally different regulatory framework that has reshaped interchange economics and accelerated real-time payment adoption. The EU's Interchange Fee Regulation (IFR, implemented 2015) capped consumer card interchange at 0.20% for debit and 0.30% for credit, years before the US began debating similar legislation through the CCCA. The initial impact was significant: an estimated EUR 2.7 billion reduction in annual interchange fees between 2015 and 2017, with merchants saving approximately EUR 1.2 billion per year. However, card schemes responded by raising other fees (scheme fees, processing fees), and the average net merchant service charge in the EU almost doubled from 0.27% to 0.44% between 2018 and 2022, effectively neutralizing the intended benefits of the regulation. This dynamic is instructive for US policy analysis: interchange caps reduce one cost component but can trigger fee increases elsewhere in the value chain.

The EU's Instant Payments Regulation (IPR, adopted March 2024) mandates that all eurozone payment service providers must be able to receive instant payments as of January 2025 and send instant payments by October 2025, with cross-border transfers within SEPA settling in under 10 seconds at charges no higher than standard credit transfers. This regulatory mandate goes significantly further than the US approach (FedNow is voluntary), and its success in driving adoption will influence whether US regulators pursue similar mandates. For FIG bankers advising on cross-border payments transactions, the regulatory asymmetry between European interchange caps and US market-set rates, and between mandated instant payments in Europe and voluntary adoption in the US, creates different competitive dynamics and valuation considerations for payments companies operating across both markets.

Payments is the financial services category where technology, regulation, and consumer behavior converge most directly. The $2.4 trillion revenue pool, the structural growth from cash-to-digital conversion, and the emerging competition between card networks, real-time rails, and alternative payment methods ensure that payments will remain one of the most active areas for FIG advisory. Whether the question involves acquirer consolidation, network regulation, cross-border expansion, or the integration of payments into embedded finance platforms, payments fluency is a foundational competency for FIG professionals.