Competition Law and Payment Gateway Market Concentration

1. Introduction

Payment gateways occupy a strategically important position in the digital-payment ecosystem. They provide the technological infrastructure through which merchants can accept payments using cards, bank transfers, wallets, UPI and other electronic payment methods. Although a gateway may appear to be merely a technological intermediary, concentration in the payment-gateway market can create significant competition-law concerns because gateways may control merchant access, transaction routing, payment data, pricing, authentication, fraud-management infrastructure and interoperability.

Market concentration becomes particularly significant where a small number of payment gateways process a large proportion of transactions. High concentration does not itself establish an infringement of competition law. The competition-law question is whether concentration creates or reinforces market power, raises barriers to entry, facilitates exclusionary conduct, or enables coordination.

The relevant legal analysis can arise under:

Article 101 TFEU – restrictive agreements;

Article 102 TFEU – abuse of dominance;

EU Merger Regulation – problematic acquisitions and concentration;

Section 3, Competition Act 2002 (India) – anti-competitive agreements;

Section 4, Competition Act 2002 – abuse of dominant position;

merger-control provisions under Indian competition law;

US Sherman Act §§ 1–2;

US merger-control principles under the Clayton Act § 7;

UK Competition Act 1998 and merger-control principles;

sector-specific payment regulation where it interacts with competition law.

2. What Is a Payment Gateway?

A payment gateway is generally a technological intermediary that facilitates communication between a merchant, payment method, acquiring institution, payment processor and other participants in the payment chain.

A simplified transaction may involve:

Customer → Payment Method → Payment Network/Bank → Gateway/Processor → Merchant

Depending upon the payment architecture, several entities can perform overlapping or distinct functions:

payment gateway;

payment processor;

acquiring bank;

card network;

issuer bank;

digital wallet;

UPI/payment interface;

fraud-management provider;

authentication provider;

merchant-service platform.

This creates an important competition-law problem: market definition cannot automatically treat all these entities as one market.

3. Relevant Market

The first major issue is defining the relevant market.

A competition authority could examine:

A. Payment-gateway services to merchants

This would focus on companies providing merchants with technological payment acceptance and routing services.

B. Online payment-processing services

The relevant market could instead encompass gateway and processing functions where merchants purchase an integrated service.

C. Card-payment acceptance

If the competitive issue concerns card transactions, the relevant market might be narrower.

D. Digital-payment acceptance

A broader market could include cards, bank transfers, wallets and other electronic payment methods.

E. Two-sided or multi-sided market

Payment ecosystems are frequently multi-sided because the service simultaneously affects:

merchants;

consumers;

banks;

payment networks;

payment processors;

technology providers.

The analysis must therefore consider indirect network effects.

4. Why Payment-Gateway Markets Can Become Concentrated

Several structural characteristics can encourage concentration.

4.1 Network effects

A gateway serving more merchants may obtain greater transaction volume and consequently more data and operational experience.

This can create a feedback mechanism:

More merchants → more transactions → more data → better fraud detection → lower costs → greater attractiveness → more merchants.

Such feedback may make market entry progressively harder.

4.2 Economies of scale

Payment infrastructure requires substantial investment in:

cybersecurity;

fraud detection;

compliance;

server infrastructure;

payment integrations;

authentication;

dispute management;

regulatory compliance.

Large gateways may therefore have lower average costs than smaller competitors.

4.3 Data advantages

Payment gateways may possess valuable information concerning:

transaction patterns;

merchant behaviour;

fraud;

customer behaviour;

payment failures;

transaction timing;

geographic patterns.

Where such data improves fraud prevention or authorization, an incumbent may develop a significant competitive advantage.

4.4 Switching costs

A merchant may have integrated a gateway into:

its website;

mobile application;

accounting software;

subscription system;

customer-management system;

refund infrastructure.

Switching may therefore require substantial technological expenditure.

This can reduce competitive pressure even where alternative gateways technically exist.

5. Competition Concerns Created by Concentration

5.1 Excessive merchant fees

A concentrated gateway market may permit providers to impose higher:

transaction fees;

gateway charges;

subscription charges;

settlement fees;

cross-border fees.

However, higher prices become a competition-law concern particularly where they result from market power or exclusionary conditions, rather than merely reflecting higher costs or superior quality.

5.2 Exclusivity

A dominant payment gateway could require merchants to use its gateway exclusively.

For example:

“Merchants using our gateway cannot simultaneously use competing payment gateways.”

Such a condition could foreclose competitors.

The analysis would consider:

duration;

percentage of merchants covered;

market share;

availability of alternatives;

switching costs;

justification for exclusivity.

5.3 Bundling

A dominant gateway could combine payment processing with:

fraud detection;

authentication;

lending;

analytics;

advertising;

cloud services;

accounting software.

If customers are effectively compelled to purchase additional services, competition-law concerns concerning tying or bundling may arise.

5.4 Self-preferencing

A gateway operating an ecosystem could potentially favour its own:

wallet;

lending product;

payment method;

merchant-financing service;

payment processor.

The relevant question would be whether the gateway uses control over infrastructure to disadvantage competing services.

5.5 Refusal to provide access

A gateway may control infrastructure necessary for merchants or competitors to participate effectively in payment markets.

A refusal to deal may become significant where:

the infrastructure is indispensable;

duplication is practically or economically impossible;

access is necessary to compete;

refusal eliminates effective competition;

there is no objective justification.

The strict conditions developed in refusal-to-deal jurisprudence remain relevant.

6. Interchange Fees and Payment-Gateway Concentration

Payment markets also involve interchange fees.

A card transaction can involve:

Merchant → Acquirer → Card Network → Issuer → Cardholder

The fee structure can affect the economics of gateways.

If a concentrated payment network increases costs upstream, gateways may have limited ability to pass those costs elsewhere.

Competition authorities therefore frequently examine the entire payment ecosystem rather than considering gateways in isolation.

7. Six Major Case Laws

Case 1: United States v. Visa U.S.A. Inc. and MasterCard International Inc.

Court: U.S. District Court, Southern District of New York
Year: 2001

This is one of the foundational payment-network antitrust cases.

Visa and MasterCard maintained rules restricting member banks from issuing competing payment cards associated with rival networks.

The US Department of Justice challenged these restrictions under Section 1 of the Sherman Act.

Competition principle

The case demonstrates that rules imposed by payment networks can produce substantial antitrust concerns where they restrict the ability of financial institutions to participate in competing payment systems.

Relevance to payment gateways

A highly concentrated gateway market could similarly become problematic if the gateway:

restricts merchants from using competing gateways;

restricts banks or processors from supporting competitors;

imposes contractual restrictions that foreclose rivals.

The case is particularly important because payment systems depend upon relationships among multiple independent participants.

8. Case 2: Ohio v. American Express Co.

Court: Supreme Court of the United States
Year: 2018

The case concerned American Express's contractual restrictions on merchants.

American Express prohibited merchants from steering customers toward alternative payment cards by informing them about potentially lower-cost alternatives.

The Supreme Court treated the credit-card platform as a two-sided transaction platform.

Competition principle

The Court emphasized that the effects on both sides of a transaction platform may need to be considered when assessing competitive effects.

Importance for payment gateways

This case is highly relevant to payment gateways because gateways also connect multiple groups.

For example:

Consumers ↔ merchants ↔ payment providers

An antitrust assessment may need to examine:

merchant prices;

consumer benefits;

transaction volume;

network effects;

quality;

innovation.

A conduct that increases prices on one side may have consequences on another side.

9. Case 3: European Commission – Visa MIF

European Commission proceedings concerning Visa's multilateral interchange fees

The European Commission investigated Visa's multilateral interchange fee arrangements.

The concern was that collectively established interchange fees could influence competition between acquiring banks and affect merchant costs.

Competition principle

The case demonstrates that payment-system arrangements can be examined under competition law even where the participants argue that common rules are necessary for efficient payment transactions.

Relevance to gateways

A concentrated gateway ecosystem could produce similar concerns where:

common pricing rules restrict competition;

gateway fees are indirectly coordinated;

participants are unable to negotiate independently;

payment intermediaries impose uniform conditions.

10. Case 4: MasterCard v European Commission

Court: Court of Justice of the European Union
Year: 2014

The MasterCard interchange-fee litigation is a major European competition-law authority concerning payment systems.

The Court examined whether multilateral interchange fees restricted competition and whether they could be justified by efficiencies.

Competition principle

A restriction is not automatically lawful merely because it facilitates the operation of a payment system.

The analysis requires consideration of:

restrictive effects;

economic justification;

efficiencies;

proportionality;

benefit to consumers.

Relevance to payment gateways

This principle is directly applicable to gateway arrangements involving:

standard transaction fees;

common technical rules;

routing arrangements;

network access rules;

settlement arrangements.

A gateway may legitimately standardize technical requirements, but standardization cannot automatically shield arrangements that substantially restrict competition.

11. Case 5: European Commission v Mastercard Inc. — Interchange Fees

Court: General Court / Court of Justice of the European Union
Period: 2012–2014

The European Commission's Mastercard proceedings concerned the competitive effects of interchange fees within the Mastercard payment system.

The European courts accepted the significance of competition between acquiring banks and examined whether the fee arrangements restricted that competition.

Competition principle

The important principle is that payment-system rules can affect competition even when they are not directly aimed at eliminating competitors.

Their economic structure can itself alter competitive conditions.

Application to gateways

A dominant gateway might create competition concerns by:

imposing minimum processing fees;

controlling routing options;

restricting merchant negotiation;

preventing multi-homing;

discriminating between payment methods.

12. Case 6: CCI – WhatsApp/Meta and Digital Payment Services

Competition Commission of India

The Competition Commission of India examined Meta/WhatsApp's conduct in the context of digital services and payments, particularly concerning WhatsApp's integration with digital-payment functionality.

The broader proceedings are significant for understanding how the CCI approaches digital ecosystems, data, network effects and leveraging.

Competition principle

Digital platforms may possess advantages arising from:

large user bases;

data;

ecosystem integration;

network effects;

control over complementary services.

Relevance to payment gateways

The same economic logic can apply where a dominant digital platform integrates payment-gateway functions with another core service.

Potential concerns include:

tying;

self-preferencing;

leveraging;

exclusion of rival payment providers;

discriminatory access;

data advantages.

13. Case 7: Google Pay / Digital Payments Competition Proceedings in India

Indian competition-law scrutiny of digital-payment ecosystems has also addressed the relationship between dominant digital platforms and payment services.

The significance of these proceedings lies in the possibility that control over a large digital ecosystem can affect competition in an adjacent payment market.

Competition principle

A company need not necessarily possess overwhelming market power in the payment service itself if its power in an adjacent market can potentially be leveraged into payment services.

Relevance to payment gateways

For example:

Dominant operating system → app distribution → payment service

or

Dominant e-commerce platform → merchant base → payment gateway

can create ecosystem-based barriers to competition.

The competition analysis must nevertheless establish the relevant market and dominance rather than assuming that ecosystem size automatically establishes a violation.

14. Case 8: Apple – App Store Payment Restrictions

Competition authorities and courts in several jurisdictions have examined Apple's restrictions concerning payment mechanisms within its app ecosystem.

Although the dispute concerns app-store payments rather than conventional merchant payment gateways, it illustrates a closely related principle: control over a technological access point can affect competition between payment providers.

Issues include:

mandatory payment systems;

commissions;

restrictions on alternative payment methods;

anti-steering restrictions;

access to consumers;

switching barriers.

Relevance

The case illustrates how a technologically controlled access point can become economically important when a platform uses its position to influence payment choices.

15. Case 9: Visa Europe / Interchange Fee Proceedings

European competition authorities have repeatedly examined Visa's interchange-fee arrangements.

The proceedings demonstrate that payment ecosystems can have horizontal and vertical competition effects simultaneously.

For example:

Card network → acquiring bank → gateway → merchant

A rule imposed at one level can influence competition at another.

Relevance to gateway concentration

A concentrated gateway may therefore need to be assessed not merely by looking at gateway market share but by examining its position within the entire payment chain.

16. Market Concentration and Merger Control

Payment-gateway concentration can increase through acquisitions.

Consider:

Gateway A + Gateway B

Even if both companies individually have modest market shares, their combination could raise concerns if:

they are close competitors;

merchants frequently multi-home between them;

they possess important transaction data;

their technologies are difficult to replicate;

they serve strategically important merchants.

Merger analysis may therefore examine:

Horizontal effects

Whether the parties directly compete for the same merchants.

Vertical effects

Whether the merged firm controls both:

payment infrastructure; and

another essential stage of the payment chain.

Conglomerate effects

Whether the company can combine payment services with:

e-commerce;

cloud computing;

advertising;

lending;

wallets;

operating systems.

17. The Importance of Multi-Homing

A particularly important feature of payment-gateway competition is multi-homing.

A merchant may simultaneously integrate:

Gateway A;

Gateway B;

Gateway C.

If switching between gateways is easy, market concentration may generate less competitive concern.

But if merchants face significant:

technical costs;

contractual restrictions;

data migration problems;

settlement problems;

certification requirements;

fraud-system integration costs,

then multi-homing becomes more difficult.

Consequently:

Number of gateways ≠ effective competitive alternatives.

Competition authorities may examine the actual ability of merchants to switch.

18. Data as a Barrier to Entry

Payment gateways generate enormous quantities of transaction information.

Large datasets can improve:

fraud detection;

credit scoring;

transaction authorization;

merchant risk assessment;

chargeback prediction.

This can create a data feedback loop:

Large transaction volume → more data → better algorithms → better service → more merchants → larger transaction volume.

From a competition perspective, the important question is whether competitors can obtain sufficiently comparable data through:

independent transactions;

open banking;

interoperability;

data portability;

partnerships;

regulatory access.

19. Interoperability

Interoperability can significantly reduce the competitive risks associated with gateway concentration.

Competition may be strengthened if merchants can easily connect different payment providers through standardized APIs.

Potentially pro-competitive measures include:

open technical standards;

API interoperability;

data portability;

standardized authentication;

non-discriminatory access;

interoperable payment rails.

However, interoperability requirements should be designed carefully because payment systems also require strong:

security;

fraud prevention;

authentication;

privacy;

operational resilience.

20. Dominance and Essential-Facility Considerations

A particularly concentrated gateway may raise an essential-facility-type question.

The inquiry would generally require examining:

Is the gateway infrastructure genuinely indispensable?

Can competitors reasonably replicate it?

Is access technically feasible?

Does denial eliminate effective competition?

Is there an objective justification?

Would mandated access improve competition without undermining security?

Dominance alone does not automatically create an obligation to deal.

21. Predatory Pricing

A large gateway could theoretically engage in:

Below-cost transaction fees → elimination of smaller competitors → subsequent price increases

The competition authority would need to establish the applicable legal test and demonstrate the relevant competitive harm.

Low prices themselves are generally beneficial to consumers and merchants. Therefore, competition law does not treat aggressive pricing as unlawful merely because competitors find it difficult to match.

22. Loyalty Rebates

A dominant gateway might offer:

“Use our gateway for 90% of your transactions and receive a substantial discount.”

Such arrangements can raise concerns where they substantially foreclose rival gateways.

Important factors include:

duration;

rebate structure;

percentage of demand covered;

ability of merchants to switch;

dominant firm's market position;

foreclosure effects;

efficiencies.

23. Exclusive Integration

Another possible concern is integration with e-commerce platforms.

Suppose a dominant marketplace says:

“Merchants selling through our platform must use our payment gateway.”

This could potentially create leveraging concerns because market power in one market may be used to protect or expand power in another.

The legal assessment would depend upon:

the relevant market;

dominance;

foreclosure;

legitimate technical justification;

efficiencies;

availability of alternatives.

24. Algorithmic Pricing

Payment gateways increasingly use algorithms to determine:

fraud risk;

transaction fees;

merchant risk;

authorization decisions;

credit limits;

routing.

Competition concerns can arise if competing gateways use algorithms in ways that facilitate:

tacit coordination;

discriminatory pricing;

exclusion;

information exchange.

However, the mere use of algorithms does not constitute an antitrust infringement.

25. Collective Concentration and Information Exchange

Payment gateways operate in an environment where transaction information is extremely valuable.

If competing gateways exchange commercially sensitive information concerning:

merchant pricing;

transaction volumes;

customer acquisition;

future pricing;

strategic plans,

this may raise concerns under rules concerning information exchange and concerted practices.

The distinction between:

legitimate technical information sharing

and

competitively sensitive information exchange

is therefore crucial.

26. Two-Sided Market Analysis

Payment markets require particular attention to two-sided-market economics.

A gateway may simultaneously serve:

Merchant side

merchants;

online retailers;

service providers.

Consumer/payment side

cardholders;

bank customers;

wallet users.

Increasing transaction volume on one side can increase value on the other.

Consequently, a competition authority should avoid evaluating gateway fees in isolation.

For example:

Lower merchant fees may increase merchant participation, which may increase consumer acceptance and transaction volume.

Conversely:

Higher merchant fees may reduce merchant participation and indirectly reduce consumer choice.

27. Competition Law and Consumer Welfare

Payment-gateway concentration can affect consumers through:

Price

Higher merchant fees may indirectly influence retail prices.

Quality

A concentrated provider may have weaker incentives to improve:

transaction speed;

reliability;

fraud protection.

Innovation

Smaller competitors may introduce:

instant settlement;

biometric authentication;

AI fraud detection;

alternative payment methods.

Choice

Merchant inability to access alternative gateways may reduce payment options.

Privacy

Greater concentration can increase the amount of transaction data controlled by one firm.

28. Indian Competition-Law Framework

For India, the principal statutory provisions are:

Section 3

Concerns agreements that cause or are likely to cause an appreciable adverse effect on competition.

Potentially relevant conduct includes:

price fixing;

market allocation;

restrictive agreements;

information exchange;

certain vertical restraints.

Section 4

Concerns abuse of dominant position.

Potential gateway conduct may include:

unfair or discriminatory conditions;

unfair pricing;

limiting technical development;

denial of market access;

leveraging dominance;

tying.

Merger control

Acquisitions involving major payment gateways can be examined to determine whether the transaction is likely to cause an appreciable adverse effect on competition.

29. A Useful Analytical Model

A competition authority investigating payment-gateway concentration could proceed through the following sequence:

Step 1 — Define the relevant market

Determine whether the market is:

payment gateways;

payment processing;

merchant acquiring;

online payment services;

digital payments;

a narrower transaction-specific market.

Step 2 — Measure concentration

Examine:

market shares;

HHI;

transaction volume;

merchant numbers;

revenue;

transaction value.

Step 3 — Identify barriers to entry

Examine:

technology;

capital;

licensing;

security certification;

merchant integration;

data;

network effects.

Step 4 — Examine switching

Determine whether merchants can:

multi-home;

switch providers;

export transaction data;

integrate competitors.

Step 5 — Investigate conduct

Look for:

exclusivity;

tying;

rebates;

discrimination;

refusal to deal;

self-preferencing;

excessive pricing;

information exchange.

Step 6 — Examine efficiencies

Consider whether the conduct produces legitimate benefits such as:

fraud reduction;

security;

reliability;

interoperability;

reduced transaction costs.

Step 7 — Evaluate foreclosure

Determine whether competitors are actually or potentially prevented from competing.

30. Key Case-Law Principles at a Glance

31. Conclusion

Payment-gateway market concentration presents a distinctive competition-law problem because payment gateways sit at the intersection of technology, finance, data and network infrastructure.

The central competition-law concern is not simply that a few companies process most payments. Instead, authorities should examine whether concentration gives firms the ability and incentive to:

exclude competing gateways;

impose restrictive contractual conditions;

prevent multi-homing;

discriminate against rival payment services;

leverage power from adjacent digital markets;

exploit network effects and data advantages;

coordinate through commercially sensitive information;

increase barriers to entry;

restrict interoperability.

The major payment cases—particularly United States v. Visa/MasterCard, Ohio v. American Express, and the MasterCard/Visa interchange-fee litigation in the European Union—show that competition law treats payment systems as economically significant networks rather than ordinary markets. The central analytical challenge is therefore to balance competition, interoperability, innovation, security and efficiency without assuming that concentration itself constitutes an antitrust violation.