What are Merchant Category Codes & How are they Used?

MCCs are standard four-digit codes assigned to businesses based on the products or services they provide, and they play a key role in how payments are processed worldwide.

Every card transaction carries more than just a payment amount. Behind the scenes, Merchant Category Codes (MCCs) help banks, payment processors, and card networks identify what a business does, shaping everything from interchange fees and fraud monitoring to rewards eligibility and transaction approval rates.

How do Merchant Category Codes Work?

MCCs are used to identify the nature of a merchant’s business. Whenever a customer makes a card payment, the MCC attached to the merchant is transmitted alongside the transaction data.

Each merchant is assigned an MCC that reflects its primary business activity - whether that be restoration services companies, tour operators, office supplies producers, or air carriers. Merchants operating in similar industries will often share the same MCC.

The purpose of MCCs is to create consistency and provide payment actors with a common framework for classifying merchants. Banks, card networks, payment processors, and financial institutions use MCC information to determine how a transaction should be treated.

MCCs are maintained by the major card networks, including Visa, Mastercard, American Express and Discover. While merchant classification standards have been formalised by the International Organisation for Standardisation (ISO), each card network maintains its own MCC framework and category definitions.

Although MCCs are broadly standardised across major card networks, certain classifications and descriptions may vary slightly between schemes.

A Brief History of MCCs

MCCs emerged in the late 1970s amidst the growth of electronic card payments. As payment networks expanded globally, credit card companies needed a consistent way to classify merchants and process transactions efficiently. MCCs became the solution, creating a standardised framework for categorising businesses across the payments ecosystem.

Initially, MCCs were primarily used for interchange fee qualification and transaction routing. Over time, their role evolved to embed numerous parts of the payments infrastructure. Today, MCCs are used in fraud protection systems, tax reporting frameworks, and regulatory compliance processes.

Merchant Category Codes remain a foundational part of how merchants accept card payments.

How Are MCCs Assigned?

MCCs are assigned during the merchant onboarding process by the acquiring bank or the payment processor.

To determine the correct code, the acquirer reviews the merchant’s products or services, business model, industry sector, expected transaction activity, and overall risk profile.

The processor then selects the most appropriate four-digit code from the standardised MCC lists maintained by the card networks.

For example, a company selling musical instruments online may receive an MCC associated with music stores, while a travel booking platform may receive a code linked to travel services.

If a business operates across multiple sectors, the acquirer will usually assign the MCC that reflects the company’s main source of revenue. A business offering both shipping services and transportation services, for instance, will typically be classified according to the activity generating the majority of its income.

How MCCs Are Used

Merchant Category Codes are dynamic and play multiple roles within the payments ecosystem.

Interchange Fee Determination

One of the most important uses of MCCs is interchange fee qualification. Interchange fees are charges paid between banks during card transactions. Different MCCs can be associated with different interchange rates depending on factors such as merchant category, transaction type, card type, regulatory treatment and applicable card network rules.

For example, interchange treatment may vary between everyday retail sectors and merchants operating in heavily regulated or specialist industries.

An incorrect MCC assignment can negatively affect payment processing costs.

Cardholder Rewards & Benefits

Many credit card rewards programmes rely heavily on MCCs. Banks use MCCs to determine whether transactions qualify for cashback, loyalty points, air miles, or other promotional offers.

For instance, a card offering “3% cashback at cocktail lounges” will typically identify eligible purchases using bar-related MCCs.

If a merchant is incorrectly coded, customers may fail to receive their expected rewards.

Spending Controls & Card Restrictions

Businesses frequently use MCCs to manage employee spending. Corporate cards can be configured to block or allow transactions from certain merchant categories.

Examples include:

Transaction Monitoring & Fraud Detection

MCCs play an important role in transaction monitoring and fraud detection. Banks and payment providers use MCC data to understand the type of transaction and assess whether it matches expected customer behaviour.

MCCs are one of many data points used within fraud monitoring systems and are typically assessed alongside transaction value, location, spending patterns, device information, and customer behaviour.

For example, a sudden transaction at an off-track betting merchant may trigger additional security checks if it differs from a customer’s normal spending activity.

MCCs also help financial institutions identify suspicious or potentially fraudulent transactions more efficiently. Certain MCCs are statistically linked to higher fraud rates or chargeback levels, which means transactions within those categories may receive closer scrutiny. This allows payment providers to apply more targeted fraud prevention measures while reducing unnecessary disruptions for lower-risk transactions.

Tax Reporting & Accounting

MCCs can also support tax reporting and accounting processes. Businesses and financial institutions use MCC information to categorise transactions and simplify financial reporting. This helps companies track spending patterns, organise expense records, and improve the accuracy of bookkeeping processes.

In some jurisdictions, MCC data may support tax reporting and transaction categorisation processes. However, tax treatment is ultimately determined by applicable tax legislation and the nature of the underlying transaction rather than the MCC itself.

As a result, accurate MCC classification is important not only for payment processing but also for financial compliance and reporting accuracy.

Compliance & Restricted Categories

MCCs help banks and payment providers identify businesses operating in regulated or restricted industries. Certain merchant categories, such as gambling, cryptocurrency, adult entertainment, or firearms-related businesses, may be subject to enhanced legal, regulatory, or compliance requirements depending on the jurisdiction in which they operate. MCCs allow financial institutions to apply the appropriate controls and monitoring measures to these transactions.

MCCs also support compliance with Anti-Money Laundering (AML), sanctions, and Know Your Customer (KYC) obligations. Transactions linked to higher-risk MCCs may require enhanced due diligence or additional reporting.

In some cases, payment providers may restrict or refuse services to merchants operating within prohibited or heavily regulated categories.

Examples of Common MCCs

Each MCC corresponds to a specific business activity. The most common merchant category codes include:

High-Risk MCCs

Financial institutions assess risk based on factors such as high chargeback rates, fraud exposure, complex regulations, reputational concerns, and compliance requirements.

For example, online gambling companies are generally viewed as higher risk than businesses providing medical services or security services.

Travel-related businesses such as tour operators and ticket agencies are also frequently treated as higher risk due to factors such as advance bookings, refund exposure, and elevated chargeback risk.

Other merchants, such as cryptocurrency services and subscription-based businesses, may be classified as high-risk because of their transaction patterns and customer behaviour. Merchant categories frequently considered higher risk by acquiring banks and payment providers include:

The classification of a merchant as high-risk can vary between payment providers and acquiring banks depending on their risk appetite, underwriting policies, and regulatory obligations.

Merchants operating under high-risk MCCs may experience higher processing fees, stricter monitoring, enhanced underwriting scrutiny, longer settlement periods, and increased reserve requirements. Because of these risks, accurate MCC classification is particularly important for high-risk merchants.

MCCs & Payment Service Providers

MCCs play an important role in how payment service providers process and evaluate transactions. When a payment is made, MCCs allow the payment provider and the customer's financial institution to identify the merchant type and assess how the transaction should be handled.

Payment service providers use this information to support fraud monitoring, risk assessment, compliance checks, and transaction routing.

MCC data may also influence processing fees, approval rates, and the application of industry-specific rules or restrictions. By accurately identifying the merchant type, MCCs ensure greater consistency, transparency, and security across the global payments ecosystem.

MCCs & Compliance

MCCs play a major role in financial compliance. Regulators and payment networks use MCCs to identify industries that require enhanced oversight and monitoring.

Anti-Money Laundering (AML)

AML regulations require financial institutions to monitor transactions for suspicious activity. MCCs help institutions identify merchants operating in sectors with elevated money laundering risk.

Banks and payment service providers often use MCC information as part of broader AML monitoring frameworks.

Know Your Customer (KYC)

KYC processes help financial institutions verify merchant identity and understand business activity. During onboarding, acquirers review merchant operations to ensure the selected MCC accurately reflects the business.

An incorrect MCC may indicate misrepresentation of business activity, increased fraud risk, regulatory exposure, or potential prohibited activity. Accurate merchant classification supports stronger KYC compliance.

PCI DSS

The Payment Card Industry Data Security Standard (PCI DSS) applies to organisations that store, process, or transmit cardholder data.

While PCI DSS requirements are not directly determined by MCCs, merchant category classification can still influence risk assessments and monitoring priorities. Certain high-risk sectors may face increased scrutiny regarding payment security controls.

How to Find Out Your MCC

Businesses can usually identify their Merchant Category Code through several methods:

Can You Change Your MCC?

Merchants cannot change their MCC directly. To update an MCC, they must prove to the acquiring bank or payment processor that their business model has changed or that the current classification is incorrect.

For example, a retail outlet that has expanded into e-commerce or subscription-based online sales may need an updated MCC that reflects its new primary revenue stream and operational model.

To update or correct your code, merchants must:

Deliberately misrepresenting your business activities to obtain a more favourable MCC may constitute fraud, breach card network rules, and violate contractual agreements with acquiring banks and payment providers.

MCCs in the Context of Open Banking & Alternative Payments

MCCs are undergoing a fundamental shift with the rise of open banking and alternative payment methods.

By enabling direct bank-to-bank transfers, these payment methods bypass traditional card networks, meaning MCCs do not influence transaction pricing in the same way they do for card-based payments. This means that merchants are no longer tied to MCC-based card processing costs in the same way as with card payments.

Nevertheless, MCCs continue to play an important role in regulatory compliance, automated tax reporting, AML checks, and transaction categorisation. They serve as key data points for transparency, risk monitoring, and structured financial analysis in open banking and alternative payments systems.

How AI is Improving MCC Management

AI and automation software are playing a growing role in how Merchant Category Codes are assigned, monitored, and maintained.

Traditionally, MCC classification relied heavily on manual reviews during onboarding. Today, AI-powered tools can analyse merchant data, transaction behaviour, website content, and business activity patterns to assist underwriting and risk teams in identifying the most appropriate MCC more efficiently. This helps reduce MCC miscoding, improves onboarding accuracy, and strengthens fraud prevention and compliance processes.

AI-driven monitoring tools can also detect unusual transaction patterns or changes in merchant behaviour that may indicate elevated risk, incorrect classification, or potential compliance concerns.

For payment providers and acquirers managing large merchant portfolios, automation can significantly improve transaction monitoring, operational efficiency, and risk management - particularly across high-volume or high-risk sectors.

As AI continues to evolve, it is expected to play an increasingly prevalent role in maintaining accurate merchant classification and supporting smarter payment operations.

FAQs

Who Assigns MCCs?

Merchant Category Codes are generally assigned by acquiring banks or payment processors during the merchant onboarding process. Card schemes maintain the official MCC frameworks.

Can an MCC Affect How Much I Pay in Card Processing Fees?

Yes. MCCs can influence interchange fees and overall card processing costs. Some merchant categories qualify for lower rates, while higher-risk categories typically attract higher fees.

What is MCC Miscoding & Why is it a Problem?

MCC miscoding occurs when a merchant is assigned the wrong category code. This can create issues involving interchange pricing, compliance, fraud monitoring, rewards eligibility, and tax reporting.

Can a Business Have More Than One MCC?

Yes. In some cases, businesses operating across multiple sectors may use more than one MCC, particularly if they operate separate merchant accounts for different business activities.

For example, a company offering both consulting and public relations services may use separate merchant accounts with different MCCs to reflect each professional service activity.

Do MCCs Apply to All Payment Types or Just Card Payments?

MCCs are primarily associated with card-based transactions. However, merchant classification concepts are increasingly used across broader financial and payment ecosystems.

What is the Difference Between a MCC & a SIC Code?

An MCC is designed specifically for payment transaction categorisation, while a Standard Industrial Classification (SIC) code is used more broadly for business and statistical classification purposes.

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Merchant Category Codes shape how payments are processed, monitored, and classified - making accurate MCC assignment essential for payment performance, compliance, and fraud prevention.

With acquiring, payment processing, and payment infrastructure built for modern businesses, DECTA helps companies manage payments more efficiently across global markets.

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