A modern card reader helps you accept card payments quickly while securely transmitting payment data between the customer, payment processor, and issuing bank.
Customers expect fast, secure checkout experiences, whether they’re shopping at a retail counter, a pop-up market, or in their own home. A survey from NMI found that 71% of respondents said they’d like to see an increase in security and fraud protection from payment technology. Finding the right card reader can help your business protect customers’ payment information.
Here’s what a card reader is; how credit card readers work; the differences between tap, chip, and swipe transactions; and how to choose the right card reader for your business.
What is a card reader?
A card reader is a device that reads payment information from customers’ payment cards or digital wallets so you can securely process transactions. It scans the card or wallet and instantly sends the data to the payment processor for approval, confirming that the payment is valid and the funds are available before the sale is completed.
Many modern card readers support multiple payment methods on a single device, allowing businesses to accept credit and debit cards, as well as digital wallets, based on customer preferences.
Card readers aren’t standalone payment solutions. They can be integrated with point-of-sale (POS) software to track sales, manage inventory, store customer data, and complete transactions. While it’s not mandatory to integrate your POS software and card reader, doing so helps avoid errors and typos, as the information is transferred automatically rather than manually.
Types of card readers
Card readers interact with credit and debit cards in a few different ways. Depending on the payment method, card issuer, and transaction amount, some transactions may also require a PIN, signature, or other verification step before approval. Businesses use different types of card readers depending on how and where they sell, and many card readers (and cards) include two or all three of the following options.
Tap card readers
Tap readers use near-field communication (NFC) to accept contactless payments. To exchange data, the reader emits a short-range wireless communication signal—just a few inches—until it receives a response from a nearby credit or debit card, smartphone, or smartwatch that’s tapped against the reader.
Contactless payment has become a preferred choice for many customers thanks to its speed and convenience. Mastercard reports that contactless now represents more than two of every three in-person transactions on its network.
Tap readers can accept:
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Contactless credit and debit cards. Payment cards with a built-in chip and antenna that let customers tap the reader to pay wirelessly.
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Mobile wallet payments.Mobile wallets like Apple Pay, Google Pay, or Samsung Pay let customers tap a smartphone or smartwatch to pay.
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Other NFC-enabled devices. Some wearables, such as specialty rings, bracelets, or smart watches, also use NFC and can tap to pay the same way as a card or phone.
Chip card readers
The little metallic square on a credit card is called an EMV chip, which stands for “Europay, Mastercard, and Visa,” the three companies that developed this global standard.
Chip card readers process EMV chip transactions. Customers insert chip cards into the reader, which reads encrypted data from the embedded chip.
EMV technology generates unique transaction information each time a payment occurs, helping reduce fraud compared to older magnetic stripe systems.
Swipe card readers
Magnetic stripe readers read information stored on the magnetic stripe of payment cards. Customers physically swipe the card through the card machine to make a payment.
Many systems still support magstripe readers, and most cards still have them, but they’re less secure than chip or contactless payment methods because magnetic stripe data is static and easier to copy. According to the US Payments Forum, US counterfeit card fraud is down more than 80% at businesses that have enabled chip readers.
How does a card reader work?
- The customer taps, inserts, or swipes a card
- The card reader captures and encrypts payment data
- The payment processor routes the transaction
- The issuing bank approves or declines the payment
- The sale is complete
The payment process takes seconds, but several systems work together behind the scenes to complete a transaction.
1. The customer taps, inserts, or swipes a card
The transaction begins when a customer presents a payment card or mobile device at the card reader. Depending on the payment method, the reader may:
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Read an EMV chip
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Scan a magnetic stripe
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Use radio waves through NFC technology to connect to a contactless card or digital wallet
Some transactions also require a PIN or customer signature, depending on the card, transaction, or seller.
2. The card reader captures and encrypts payment data
To protect sensitive payment information during transmission, the card reader encrypts card or mobile wallet data, turning the payment details into coded information only authorized payment systems can read. Encrypted data may include:
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Card number
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Transaction amount
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Seller information that identifies which business and checkout device initiated the transaction, so the payment can be routed correctly and tied to the right sale
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Authentication details, such as one-time security codes or device verification, used by the payment network and issuing bank before approving the transaction
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A “token”—a package sent in place of the actual data
3. The payment processor routes the transaction
Once the card reader captures the payment information, it sends that encrypted data to a connected POS system or directly to the payment processor, depending on the setup. The POS records the sale and adds order details, while the payment processor routes the transaction through the card network to the issuing bank for approval.
The processor then sends the data to several financial systems, including:
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The card network. Networks like Visa, Mastercard, or American Express, which route the transaction between the issuing bank and the seller’s bank.
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The merchant account. The business’s account that temporarily holds funds before they’re deposited into the seller’s primary bank account.
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The issuing bank. The bank that issued the customer’s card and approves or declines the transaction based on available funds.
4. The issuing bank approves or declines the payment
The issuing bank checks whether:
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The card is valid
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The account has available funds
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The transaction appears legitimate
The bank then sends an approval or decline response back through the payment network. This process typically takes only a few seconds.
5. The sale is complete
The approval message returns to the POS system and card reader, completing the transaction.
The customer receives a receipt, and the payment moves through settlement—the process of transferring funds from the customer’s bank to the business’s bank account. Depending on the payment provider, this can happen the same day or within a few business days.
How card readers keep payments secure
Modern card readers use several layers of protection.
EMV chip technology
EMV chip cards generate unique transaction codes for every purchase. Even if someone intercepted transaction data, they couldn’t easily reuse it, because the only thing that is sent is what’s needed for that specific transaction.
End-to-end encryption
End-to-end encryption protects payment data from the moment a customer pays until it reaches the payment processor or financial institution. The card reader converts payment details into coded data before sending it. Authorized payment systems can decode that information, but anyone intercepting it along the way would only see unreadable data.
PCI compliance
Payment systems must comply with the Payment Card Industry Data Security Standard (PCI DSS), a set of security requirements created by the major card networks. PCI DSS helps protect payments by requiring businesses and payment providers to use secure networks, limit access to cardholder data, and regularly monitor systems for vulnerabilities or suspicious activity.
Tokenization
Some systems use “tokens.” Tokenization protects your card by replacing your actual number with a unique digital placeholder during checkout. Since the token only works for that specific transaction, even if a hacker were to access it, they wouldn’t be able to use it to find your real card number or make fraudulent purchases.
Why choosing the right card reader matters
Card readers let you accept payments anywhere you go. “I love that I can access Shopify POS anywhere and process payments right at clients’ homes without worrying about paying extra fees.” Sat Gurumukh Khalsa, founder of Sukhmani Designs, tells Shopify.
The right card reader affects customer experience, operational flexibility, and transaction costs. Here are a few considerations:
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Customer experience. Fast tap, chip, and mobile wallet payments shorten checkout times and give customers more ways to pay.
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Operational flexibility. Portable readers can make it easier to accept payments at pop-ups, events, tableside, or in customers’ homes, while countertop terminals work better for fixed checkout stations.
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Transaction costs. Some payment providers offer different processing rates depending on whether the card is physically present and whether the reader integrates with the payment system.
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Business visibility. When a card reader is connected to a POS system, payment data can sync with inventory, orders, and customer records automatically.
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Sales data. Payment hardware also generates valuable sales data. Connected to a POS, card readers can automatically record transaction details like purchase totals, payment methods, and sales timing.
Shopify POS card readers
Shopify POS bridges the gap between your online store and physical shop by syncing everything into a single, easy-to-use system. It lets you take in-person card payments while automatically updating your inventory, orders, and customer data across all your sales channels in real time. Your hardware options include:
Shopify Tap & Chip Card Reader
The Shopify Tap & Chip Card Reader supports:
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EMV chip payments
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Contactless payments
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Debit cards and credit cards
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Bluetooth and USB-C connectivity
With its compact size, wireless connection, and portability, it’s designed for mobile selling environments and smaller checkout setups—think kiosks, coffee carts, or farmers markets.
WisePad 3
The WisePad 3 supports chip and contactless payments and is PCI compliant. It connects through Bluetooth to iPad, iPhone, or Android devices, or via USB-C to Android devices, and is available in supported international markets. The Shopify Tap & Chip Card Reader is available only in the US.
Shopify POS Terminal
The Shopify POS Terminal is an all-in-one countertop payment terminal with a built-in customer-facing screen. Customers can tap, insert, or swipe their card directly on the device, which stays at the checkout area rather than moving around like a portable reader.
Tap to Pay
Tap to Pay on iPhone with Shopify POS lets you accept card-present payments directly on an iPhone without separate hardware.
The iPhone uses built-in NFC—the same short-range wireless technology used in tap readers—to create a secure connection with a customer’s contactless card, smartphone, or smartwatch. When the customer taps to pay, the iPhone receives the encrypted payment credentials and sends them through Shopify POS to the payment processor for approval.
Retailers using Shopify Payments with compatible Shopify POS hardware—the Shopify Tap & Chip Card Reader, WisePad 3, Shopify POS Terminal, or Tap to Pay on iPhone—may also qualify for lower card-present processing rates compared to manually keyed transactions.
How to choose the right card reader
The best card reader depends on how your business operates. Consider these factors:
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Selling environment. A mobile business, like a table at a farmers market, may benefit from portable Bluetooth readers, while a retail storefront may prefer a countertop terminal.
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Payment methods. According to S&P Global 451 Research, 53% of US consumers prefer contactless for in-store payments.
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POS integration. Choose hardware that works smoothly with your POS and existing systems. A card reader that integrates with your POS can automatically update inventory after each sale, attach payments to online or in-store orders, and keep customer purchase records in one place.
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Security features. Look for EMV compliance, encrypted data transmission, and PCI compliance. Businesses with larger teams or multiple checkout locations may want added controls like employee PINs or user permissions, so only authorized staff can access payment settings or issue refunds.
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Country compatibility. Some readers are available only in certain countries or regions. For example, the Shopify Tap & Chip Card Reader is available only in the US. Check hardware compatibility before purchasing.
How does a card reader work FAQ
What’s the difference between tap, chip, and swipe?
Tap, chip, and swipe are three ways credit and debit cards can provide information for payments. Here’s how they work:
- Tap payments use NFC to exchange data wirelessly.
- Chip payments use EMV chip technology for secure authentication.
- Swipe payments use magnetic stripe data stored on the back of the card.
Do you need a POS system to use a card reader?
No. Some card readers can work on their own and send payments directly to the payment processor. But connecting a card reader to a POS system can make it easier to track sales, manage inventory, and keep payment records organized.
Can you accept payments without a physical card reader?
Yes, you can accept payments without a physical card reader by using tap-to-pay technologies like Shopify’s Tap to Pay on iPhone with Shopify POS.
