The four major credit card networks process more than $27.7 trillion in consumer transactions worldwide every year. For merchants, they are not interchangeable. Each network operates a distinct business model, charges different fees, achieves different authorization rates, and carries different acceptance footprints across the geographies a business sells into.
Most existing content on this topic is written for cardholders deciding which card to carry. This guide is written for the other side of the transaction. It covers what each network actually is, how they differ in ways that matter for cost and acceptance, what the 2025-2026 shifts (including Capital One’s acquisition of Discover) mean for merchants, and how a modern payment stack should route across all four.
Before the deeper analysis, the short version:
The structural difference between open-loop (Visa, Mastercard) and closed-loop (Amex, Discover) is the single most important distinction merchants need to internalize. It shapes fees, dispute handling, acceptance dynamics, and routing options across the entire payment stack.
A credit card transaction involves more parties than most merchants realize. The card network sits at the center of the flow, but it is one of several distinct roles. To understand how the four networks differ, it helps to map them against the broader payment orchestration vs gateway vs processor model first.
The participants in a card transaction are:
The card network’s job is to authorize the transaction, route the authorization between the issuing bank and the acquiring bank, set the scheme rules, and define the interchange and assessment fees that flow between participants.
In open-loop networks (Visa, Mastercard), all seven roles are filled by different parties. In closed-loop networks (Amex, Discover), the network combines the issuing bank, card network, and acquiring functions into a single entity, which is why Amex and Discover can charge merchants directly without an external acquirer.
This is the framing every merchant should understand because it determines how fees, disputes, and acceptance work for each network.
Visa and Mastercard do not issue cards. They do not lend money. They operate the network that connects thousands of issuing banks on one side with thousands of acquiring banks on the other, and they earn revenue from scheme fees on every transaction that flows across that network.
The advantage of open-loop is scale. Because any bank can issue Visa or Mastercard cards and any acquirer can process them, both networks have achieved global ubiquity. The trade-off is that interchange (the largest single fee on most card transactions) flows to the issuing bank, not the network itself. The network earns smaller scheme fees, but on enormous volume.
American Express and Discover both issue their own cards, hold the credit relationship with the cardholder, and process the merchant side of the transaction themselves. This single-entity model means the closed-loop network captures all the economics from a transaction rather than splitting them across an issuer-network-acquirer chain.
The advantage of closed-loop is margin. Amex and Discover can charge merchants higher fees because there is no separate issuer to compensate, and they retain control of the entire customer relationship on both sides. The trade-off is acceptance. Because closed-loop networks have to recruit merchants directly rather than relying on the open-loop network effect, they have historically achieved lower acceptance, particularly outside their home markets.
Understanding which network is which determines what merchants can expect when they accept a card. Visa and Mastercard transactions flow through the merchant’s chosen acquirer. Amex and Discover transactions flow through the closed-loop network directly, often with a separate merchant agreement.
Visa is the largest card network in the world by every measurable metric.
Scale and reach. Visa processed roughly 257.5 billion transactions globally in 2024, a 10% year-over-year increase. The network holds approximately 52.2% of the global credit card market and around 60% of the US card network market by purchase volume. There are more than 4.48 billion Visa cards active worldwide.
Business model. Pure open-loop. Visa does not issue cards, does not extend credit, and does not hold consumer or merchant accounts. The company’s revenue comes from data processing fees, service fees, and international transaction fees charged to the issuing and acquiring banks on its network.
Merchant economics. Visa’s interchange typically ranges from 1.43% to 2.4% depending on card type, transaction channel, merchant category, and geography. Premium and rewards cards carry higher interchange than standard consumer cards. Card-present transactions incur lower interchange than card-not-present transactions due to the lower risk profile. Cross-border transactions add interchange adjustments and currency conversion costs on top of base rates.
Where merchants see Visa most. Effectively everywhere. Visa is the default network for retail, hospitality, ecommerce, and most other categories in most geographies. For a merchant operating internationally, Visa volume is almost always the largest share of card transactions.
Recent developments. Visa has invested heavily in Click to Pay, network tokenization, and Visa Direct (its real-time payments platform). These investments are repositioning the network from a card-only authorization layer to a broader payments infrastructure provider.
Mastercard is the second-largest network and the one closing the gap on Visa fastest in several dimensions.
Scale and reach. Mastercard processed around 160 billion transactions in 2024 with approximately $2.997 trillion in card volume reaching 500 million consumers worldwide. The network has 3.158 billion active cards. Mastercard is accepted in more countries and territories than any other network globally (210+).
Business model. Open-loop, identical to Visa in structure. Banks issue Mastercard-branded cards; Mastercard operates the network connecting them.
Merchant economics. Mastercard interchange typically ranges from 1.55% to 2.6%. Slightly higher on average than Visa but the ranges overlap substantially. Mastercard’s scheme fee structure is broadly comparable to Visa’s, with similar adjustments for card type, channel, and geography.
Where merchants see Mastercard most. Strong global coverage with particular strength in Europe and emerging markets. In the US, Mastercard is roughly half Visa’s volume but accepted nearly universally wherever Visa is.
Strategic positioning. Mastercard has been more aggressive than Visa in commercial cards, fintech partnerships, and tokenization infrastructure. The Mastercard Merchant Cloud product launched in 2024 bundles network tokenization, Click to Pay, and gateway services as a single offering. Gr4vy’s October 2025 partnership with Mastercard integrates Mastercard Merchant Cloud directly into the orchestration platform, allowing merchants to enable network tokenization and Click to Pay through a single integration without additional development work.
American Express occupies a distinctive position as the largest closed-loop network and the network with the highest average transaction value.
Scale and reach. Amex has approximately 127.6 million basic cards in force worldwide, with around 67 million active cardholders in the US in 2025. The average Amex transaction value sits at $155, the highest of any major network and a direct reflection of its premium and corporate card concentration.
Business model. Primarily closed-loop, but with hybrid arrangements. Most Amex cards are issued by American Express itself. A smaller segment is issued by partner banks under Amex’s network rules. Either way, transactions flow through Amex’s own processing infrastructure rather than through external acquirers.
Merchant economics. Amex charges merchants the highest discount rates of the four major networks, typically 2.5% to 3.5% per transaction, sometimes higher for small merchants without volume-based negotiations. This is the primary reason Amex acceptance is narrower than Visa or Mastercard: the higher fee creates a real cost question for low-margin merchants.
Where merchants see Amex most. Travel, hospitality, restaurants, B2B procurement, and premium retail. Amex’s customer base skews higher-income and higher-AOV, which is why merchants in those categories generally accept it despite the higher fees. In the US, roughly 99% of retailers that accept credit cards now accept Amex, but international acceptance remains 30-40% behind Visa and Mastercard.
Dispute handling. Amex’s closed-loop model means disputes are handled internally rather than through the merchant-acquirer-network-issuer chain that governs Visa and Mastercard chargebacks. This can simplify some processes but also gives Amex more unilateral authority in dispute outcomes than open-loop networks typically have.
Discover is the smallest of the four major US networks but the one undergoing the most structural change. Capital One’s acquisition of Discover closed in February 2025, fundamentally altering the network’s strategic position.
Scale and reach. Discover holds approximately 5.9% of US credit card purchase volume, with around 71.5 million Discover credit cards in circulation. The Discover Global Network processed approximately $500 billion in worldwide transaction value in 2025, a 7% increase year over year. International acceptance flows through alliance partnerships with Diners Club, UnionPay, JCB, RuPay, BC Card, and Elo, which together cover 185 countries and territories.
Business model. Closed-loop. Discover issues its own cards, processes its own transactions, and historically focused on the US domestic market. The network’s growth strategy has leaned on alliance partnerships for international acceptance rather than direct expansion.
Merchant economics. Discover’s discount rate typically ranges from 1.56% to 2.3%, broadly comparable to Visa and Mastercard rather than to Amex despite its closed-loop structure. This pricing strategy reflects Discover’s effort to maintain merchant acceptance in the US market.
The Capital One acquisition and what it means. Capital One’s $35.3 billion acquisition of Discover, completed in February 2025, gives Capital One control of a major card network for the first time. The strategic implication is that Capital One can potentially route its own card transactions through Discover’s network rather than Visa or Mastercard, capturing more of the transaction economics internally. For merchants, this means the Discover-branded transactions they accept may grow as Capital One migrates its issuer portfolio onto the network, and the competitive pressure on Visa and Mastercard interchange may increase over the medium term.
Where merchants see Discover most. Predominantly US-based transactions. Cashback rewards programs, particularly among middle-market consumer segments. Through alliance partners, Discover-branded transactions also appear in cross-border flows from China (UnionPay), Japan (JCB), and several other markets.
For merchants operating internationally, the four major networks above are not the only ones that matter. Four secondary networks come up frequently:
UnionPay. China’s domestic and increasingly international network. UnionPay handles more transactions globally than any other network by volume, though most are within China. Merchants targeting Chinese cross-border ecommerce or inbound travel from China benefit significantly from UnionPay acceptance, which is now widely available through Discover Global Network and direct integrations.
JCB. Japan’s primary domestic network, with extensive Asia-Pacific reach and partnership-based US acceptance through Discover.
Cartes Bancaires. France’s domestic network, which co-brands with Visa and Mastercard. Routing transactions through CB rather than the international networks can reduce costs and improve authorization rates for merchants with French customer bases.
Elo. Brazil’s domestic credit card network, important for merchants selling in Latin America’s largest ecommerce market.
For merchants with cross-border operations, supporting these secondary networks through local acquiring relationships is often the difference between strong and weak authorization rates in those markets. Our analysis of how to increase payment approval rates in 2026 covers the routing logic in more detail.
The four major networks across every dimension that matters for a merchant evaluation:
| Dimension | Visa | Mastercard | American Express | Discover |
|---|---|---|---|---|
| Network model | Open-loop | Open-loop | Closed-loop | Closed-loop |
| Issues cards directly? | No | No | Yes | Yes |
| Global market share | ~52.2% | ~24% | ~10% | ~6% |
| Active cards worldwide | 4.48B | 3.16B | 127.6M | 71.5M |
| Annual transactions (2024) | 257.5B | 160B | ~9B | ~2.5B |
| Acceptance (countries) | 200+ | 210+ | 100+ | 185 (via alliances) |
| Typical merchant fee | 1.43% – 2.4% | 1.55% – 2.6% | 2.5% – 3.5% | 1.56% – 2.3% |
| Average transaction value | $93 | ~$95 | $155 | ~$80 |
| BIN prefix (primary) | 4 | 51-55, 2221-2720 | 34, 37 | 6011, 622126-622925, 644-649, 65 |
| Card number length | 13, 16, or 19 digits | 16 digits | 15 digits | 16 digits |
| Strongest in | All geographies, all channels | Europe, emerging markets, B2B | Premium, travel, US corporate | US domestic, cashback |
| Recent development | Click to Pay rollout, Visa Direct | Mastercard Merchant Cloud launch | Premium repositioning | Capital One acquisition (Feb 2025) |
The “Visa is cheaper than Amex” framing common in consumer-finance content oversimplifies what merchants actually experience. The real picture has more dimensions:
Interchange varies more by card type than by network. A premium rewards card on any network costs more than a standard consumer card on any network. The interchange tables maintained by Visa and Mastercard are extensive, with hundreds of categories. A Visa Signature card may cost more than a basic Mastercard, even though Mastercard’s typical range is slightly higher.
Closed-loop networks have flatter pricing. Amex and Discover do not split interchange and scheme fees between issuer and network because they are both. Their merchant pricing is typically a single discount rate, which is simpler to model but can be higher in absolute terms.
Geographic mix matters more than network mix. A merchant processing 60% of volume in Europe through CB or domestic networks will have a different effective rate than one processing through Visa internationally, regardless of which network logos appear on the cards.
Card-not-present always costs more. Ecommerce interchange is consistently higher than card-present across all four networks, sometimes by 30-50 basis points. The risk premium is built into the rate.
Volume matters. Enterprise merchants negotiate. The published ranges above reflect typical small and mid-market pricing. High-volume merchants achieve materially lower effective rates across all four networks through volume-tier negotiations with their acquirers and direct deals with Amex.
For more detail on the fee structure across networks, see Gr4vy’s guide to credit card processing fees.
Beyond fees, the metric that has the biggest revenue impact for merchants is the percentage of attempted transactions that get approved. Authorization rates differ meaningfully across networks for reasons that merchants should understand:
Network-level differences are smaller than acquirer-level differences. A Visa transaction routed through a strong local acquirer can outperform a Visa transaction routed through a weak foreign acquirer by 10-15 percentage points. The network is the same; the routing makes the difference.
Closed-loop networks have unified visibility. Because Amex and Discover handle both the issuer and acquirer sides, they can sometimes achieve more consistent authorization decisions than open-loop networks where issuers and acquirers operate independently.
Tokenization affects networks differently. Network tokenization (Visa Token Service, Mastercard Digital Enablement Service, and their equivalents) typically improves authorization rates by 2-7 percentage points compared to raw PAN transactions. The lift is meaningful and reasonably consistent across networks, but the implementation maturity varies.
Cross-border patterns differ. International transactions face additional decline pressure regardless of network, but the specific reasons differ. Visa transactions decline more often for AVS mismatches; Mastercard transactions decline more often for issuer-level velocity rules; Amex transactions decline more often for closed-loop fraud screening; Discover transactions face higher decline rates simply because issuers see them less frequently and may flag them as anomalous.
For merchants accepting all four networks, routing each transaction to the acquirer best positioned for that specific network in that specific geography typically improves overall authorization rates by 2-10 percentage points, with cross-border gains often higher. Intelligent payment routing is the mechanism that delivers this lift in practice.
The distribution of which networks your customers use is genuinely informative about who they are and how they shop.
Heavy Visa and Mastercard with low Amex/Discover share typically signals a broad mass-market customer base, often international, often price-sensitive. Most ecommerce merchants outside the premium category see this pattern.
Elevated Amex share correlates with premium positioning, B2B customers, travel-related categories, and US corporate buyers. If Amex is 15%+ of your volume, you are likely serving a higher-income segment regardless of how your brand positions itself.
Elevated Discover share typically indicates a US domestic customer base in middle-market consumer categories. Discover users skew toward cashback-conscious shoppers in retail, restaurants, and services.
Significant cross-border network presence (CB, JCB, UnionPay) indicates real international reach. Most merchants underestimate how much of their cross-border revenue depends on supporting these networks at the local acquirer level.
The strategic implication is that the network mix should inform routing strategy. A merchant with 20% Amex volume needs an acquirer relationship that performs well on Amex. A merchant with significant UnionPay volume needs a routing path that handles UnionPay efficiently. A single-acquirer setup that performs well on Visa but poorly on Amex is leaving real revenue on the table.
For merchants operating across all four networks, the architectural question becomes how to ensure each network’s transactions reach the acquirer most likely to approve them. This is the problem payment orchestration was designed to solve.
A modern orchestration setup routes transactions based on multiple variables in real time:
The merchant maintains relationships with multiple acquirers and the orchestration layer chooses the best path for each transaction. This is materially different from the single-PSP model in which every Visa transaction, every Mastercard transaction, every Amex transaction goes through the same processor regardless of fit.
For merchants with annual payment volume above $50M and multi-network mix, the typical authorization rate improvement from this kind of routing is in the 2-10% range. Combined with network tokenization, which protects card-on-file payments from expired-card declines, the cumulative revenue impact is often the largest single optimization a payments team can deliver.
For US merchants specifically, a regulatory development worth tracking is the Credit Card Competition Act (CCCA). If enacted, the legislation would require large banks to offer merchants alternative payment networks beyond Visa and Mastercard for credit card transactions, broadly mirroring the routing competition that already exists for debit cards under the Durbin Amendment.
The CCCA was not included in the GENIUS Act that passed in 2025, but the underlying interchange-reform pressure has not gone away. If enacted, the legislation could meaningfully reduce interchange revenue and create new routing options for merchants. The merchants best positioned to benefit are those whose payment stacks can already route flexibly across multiple acquirers and networks, which is exactly the architecture that orchestration enables.
Visa and Mastercard are open-loop networks that do not issue their own cards; they operate the network connecting issuing banks and acquirers. American Express and Discover are closed-loop networks that issue their own cards and process their own transactions, capturing more of the transaction economics. The structural difference shapes merchant fees, dispute handling, and acceptance dynamics.
Visa is the largest by every measurable metric. It processes around 257.5 billion transactions per year, holds approximately 52.2% of the global credit card market, and has more than 4.48 billion active cards worldwide.
American Express typically charges the highest merchant discount rates, ranging from 2.5% to 3.5% per transaction. The other three networks (Visa, Mastercard, Discover) all sit in the 1.43% to 2.6% range for typical transactions, with overlap between them.
Because Amex operates a closed-loop model, it captures all the transaction economics directly rather than splitting them between an issuer and a separate acquirer. Its premium card portfolio also justifies higher merchant fees in exchange for higher average transaction values (Amex’s average transaction is $155, well above the other networks).
In an open-loop network (Visa, Mastercard), the issuing bank, the network, and the acquiring bank are three separate entities. In a closed-loop network (American Express, Discover), all three functions are performed by the same company. Open-loop networks achieve broader acceptance through their network effects; closed-loop networks capture higher per-transaction economics.
The first digit of a card number identifies the network: Visa starts with 4, Mastercard starts with 51-55 or 2221-2720, American Express starts with 34 or 37, and Discover starts with 6011, 622126-622925, 644-649, or 65. Visa card numbers are 13, 16, or 19 digits; Mastercard and Discover are 16; American Express is 15.
Yes, in the medium term. Capital One closed its $35.3 billion acquisition of Discover in February 2025. Capital One can now route its own card transactions through the Discover network, capturing more transaction economics internally. For merchants, this is likely to increase the share of Discover-branded transactions over time and may apply competitive pressure on Visa and Mastercard interchange rates.
For most merchants in most categories, yes. Restricting accepted networks to avoid fees usually loses more revenue from declined customers than it saves in interchange. The exception is small merchants serving demographics with very low Amex or Discover usage, where the cost-benefit analysis can favor selective acceptance. Enterprise merchants almost always accept all four because their customer mix is broad enough that any restriction creates measurable revenue loss.
The differences are real but smaller than most merchants assume. Network-level authorization rate variation is typically within a few percentage points, but how a transaction is routed (to a local acquirer vs a foreign one, with or without network tokenization, through a strong or weak processor for that specific BIN range) makes much more difference than the network itself. Intelligent routing across multiple acquirers per network typically improves authorization rates by 2-10%.
Each major network operates its own tokenization service: Visa Token Service, Mastercard Digital Enablement Service, Amex Token Service, and Discover’s tokenization through ProtectBuy. Network tokens replace stored card numbers with network-issued tokens that automatically update when underlying cards are reissued or expire. The result is fewer declined transactions on stored credentials and improved security. Network tokenization typically delivers a 2-7 percentage point authorization rate improvement on card-on-file transactions across all networks.
Yes. UnionPay (China) handles more transactions globally than any other network by volume. JCB (Japan) has strong Asia-Pacific presence. Cartes Bancaires (France) co-brands with Visa and Mastercard and routing through CB can reduce costs in the French market. Elo (Brazil) is essential for Brazilian ecommerce. For merchants with international customer bases, supporting these networks through local acquiring relationships is often the difference between strong and weak authorization rates in those geographies.
A payment orchestration platform connects to multiple acquirers and processors at once, then routes each individual transaction to the path most likely to approve it based on the card’s network, BIN range, geography, currency, and historical performance. For merchants accepting all four major networks plus regional ones, this delivers 2-10% authorization rate improvements and meaningful cost optimization without requiring the merchant to switch any of their existing providers.
The four credit card networks are not interchangeable, and the differences matter for merchant economics, acceptance, and authorization rates. Visa and Mastercard offer the broadest acceptance and the most predictable economics. American Express commands premium fees in exchange for premium transaction values. Discover is reshaping under Capital One’s ownership in ways that may benefit merchants over time.
The architectural implication for enterprise merchants is that the network mix in your transaction volume should inform your acquiring strategy. Single-acquirer setups that perform well on one network often underperform on others. The merchants who extract the most value from their card acceptance are the ones who route each transaction to the acquirer best positioned for its specific network, geography, and card type.
If you’re evaluating how your current setup performs across the four networks, or want to understand where intelligent routing could improve your authorization rates and acceptance costs, contact our team for a walkthrough of how Gr4vy’s orchestration platform routes across acquirers, networks, and geographies through a single integration.
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