Credit card use is rising in the United States. According to data from TransUnion, in Q1 2024, there were 543.1 million credit cards in circulation, up from 523.2 million in Q1 2023^[1]. With the increasing prevalence of credit card use, it might be useful to know how to identify the type of credit card you are using or being presented with.

This guide will explore credit card numbers and explain how to tell the credit card type by the first four digits. You'll also learn about a method that can help you secure your online transactions.

Understanding Credit Card Numbers—The Basics

A credit card number, officially known as a Primary Account Number (PAN), is a unique identifier assigned to each credit card. Debit cards also have PANs, as they follow the same numbering convention. Credit card numbers typically consist of 16 digits, although some may have between 13 and 19 digits, and you can usually find them on the front of the card. 

These numbers are not randomly generated but follow a specific pattern set by the American National Standards Institute (ANSI) and the International Organization for Standardization (ISO). Every credit card issuer must follow this pattern when generating credit card numbers. 

The first six (sometimes eight for newer cards) digits of a credit card number are known as the Issuer Identification Number (IIN) or Bank Identification Number (BIN). They identify the credit card issuer or bank, the type of card (credit or debit), and the region where the card was issued. The following nine to 12 digits are the account number, which identifies the specific cardholder's account.

The last digit is known as the check digit and is used to validate the credit card number’s accuracy during a transaction. Credit card issuers use the Luhn algorithm, a mathematical formula, to generate the check digit^[3]. Upon summing all the digits of a credit card number, including the check digit, if the total has a sum value divisible by 10, then the credit card number is considered valid.

Other Numbers You'll Find on a Credit Card and Their Meaning

Apart from the PAN, you'll also find other numbers on a credit card—the expiration date and security code:

• Expiration date—It typically consists of two digits for the month and two for the year (MM/YY) and reveals when the card will no longer be valid. For instance, if the expiration date is 06/25, it means that the card expires in June 2025. Expiration dates help check the card’s validity and ensure cardholders get new, updated cards periodically.
• Security code—Known as the Card Verification Value (CVV) or Card Verification Code (CVC), it's a three- or four-digit code typically found on the back of a Visa, Mastercard, or Discover card and the front of American Express cards. It's used as an additional security feature to verify the card is in the possession of the cardholder during online transactions.

Determining Credit Card Type by the First Four Digits

The first digit of the BIN represents the major industry identifier (MII). Each MII corresponds to a specific credit card issuer category, as shown below:

The first four digits also provide a more specific identification of the credit card network. For example, Visa^® cards always start with 4, Mastercard^® starts with 2 or 5, and American Express^® starts with 34 or 37. Discover^® cards start with 6, while Diner's Club International^® cards begin with 30, 36, 38, or 39.

While the first four digits might reveal what network the card belongs to, you’ll need the whole BIN number to reveal more information about the card.

For instance, if a card starts with 4715, with this information, it's easy to discern that it is a Visa card. Based on those four numbers alone, you can’t tell whether it’s a prepaid debit card issued by Bank of America, a credit card issued by Chase, or another type of card issued by another bank that issues Visa cards. A card that starts with 5524 is a Mastercard, but it can be a credit card issued by the Commonwealth Bank of Australia or a debit card issued by Morgan Stanley. 

How Are BINs Used in Transactions?

BINs are critical for successful payment processing. They help merchants accurately verify customer information and ensure efficient routing of transactions to the right banks. 

When a transaction is initiated, the BIN determines the card type and issuing bank. What follows is a series of events to complete the payment:

1. The merchant's POS system or website sends the credit card information to their bank (also known as the acquiring bank) to request payment authorization.
2. The acquiring bank sends the credit card information to the card issuer to request authorization for the transaction.
3. The card issuer approves or declines the transaction based on the available credit balance, account status, and any other security measures it has in place. If approved, a code is sent back to the acquiring bank.
4. The approving code is then sent back to the merchant's POS system or website, and if all goes well, the transaction is completed. 
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The entire process typically takes a few seconds to complete, and the merchant will receive payment for the transaction within 1 to 3 business days.

How Secure Are Credit Cards?

Determining the type, issuer, and location of a credit card is one of the security measures that reduce the risk of card fraud by helping merchants verify the authenticity of a card. If a transaction seems suspicious due to a mismatch between the BIN origination and the transaction location, merchants can take additional steps to verify the cardholder's identity before completing the transaction.

Credit cards employ other security measures to protect cardholders against fraud, including:  

• EMV chip technology—EMV (Europay, Mastercard, and Visa) chips are designed to enhance security by generating a unique code for every transaction. EMV chip technology makes it difficult for fraudsters to clone cards, compared to how it was with traditional magnetic stripe cards.
• Fraud alerts and monitoring—Credit card companies use sophisticated systems to monitor transactions and detect unusual or suspicious activity on your account.
• Zero-liability policy—If you report unauthorized charges on your credit card, most card issuers have a zero-liability policy that protects cardholders from being held liable for fraudulent transactions. Under the Fair Credit Billing Act, you are only responsible for up to $50 of unauthorized charges, but most credit card companies waive this fee.

While both credit and debit cards enjoy specific protections, these may not be enough—payment card numbers and other information such as the expiration date and CVV can still be stolen and used fraudulently. Using virtual cards for online payments is a way to reduce the risk of sensitive data exposure by substituting your card data with randomly generated card numbers. Dedicated virtual card providers like Privacy offer industry-grade security and robust card controls to help safeguard against unexpected charges.

Privacy Is Your Secret To Secure Online Transactions

When you connect a bank account or debit card to Privacy, you’ll be able to generate virtual cards with unique 16-digit numbers, expiration dates, and CVV codes. You can use those cards for most online transactions, knowing that your real financial information remains protected on Privacy servers.

With Privacy, you can create three card types that protect you in different ways:

1. Single-Use Cards—Designed for one-time use, these cards close shortly after completing the first transaction, rendering them useless to hackers. You can use a Single-Use Card for purchases on unfamiliar or unsecured websites.
2. Merchant-Locked Cards—These cards "lock" to the first merchant you use them with and decline subsequent transactions from different vendors. They're ideal for purchases on trusted online stores and for recurring charges like Amazon, Apple, and Google subscriptions.
3. Category-Locked Cards—These cards "tie" to a predefined merchant category, such as travel, dining, or health and wellness. Transaction attempts by merchants outside that category will be automatically declined. Category-Locked Cards help you budget and control your spending on specific services or products.
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Privacy lets you set spending limits and pause, unpause, or close your virtual cards anytime without impacting the underlying funding source. Privacy will block further charges on a paused or closed card and decline those that exceed your preset spending limit.

Privacy Makes Virtual Card Management Seamless

Accredited by the BBB^®, Privacy offers additional convenience features designed to make your virtual card management effortless:

• Mobile app—Install the Privacy App on your iOS or Android device to create and manage virtual cards wherever you are. Privacy will send real-time notifications whenever your virtual card is charged or declined, enabling timely detection of potentially suspicious activities.
• Browser extension—The Privacy Browser Extension lets you quickly generate and autofill virtual cards at checkout, making online shopping faster and more secure. The extension is available for popular browsers, including Chrome, Firefox, Safari, Edge, and Safari for iOS.
• 1Password integration—The password manager integration enables you to manage your passwords and Privacy Virtual Cards from 1Password’s browser extension.
• Shared Cards—Privacy allows you to share virtual cards with close family and friends, making it easier to manage family expenses or share your budget without revealing sensitive financial information.

How To Start Using Privacy Virtual Cards

If you're a U.S. resident, at least 18 years old, and have a checking account with a U.S. financial institution, here's how you can sign up and use Privacy Virtual Cards:

1. Register
2. Fill out the required Know-Your-Customer (KYC) information
3. Connect a funding source, such as your debit card or bank account
4. Request and generate a Privacy Card
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Privacy offers four monthly plans to choose from:

Privacy Cards can be used at any online merchant that accepts U.S. Visa^® or Mastercard^®, including popular vendors like Curology, Walmart, and Peloton.

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