Using a credit card reader involves connecting the device to your phone, tablet, or point-of-sale terminal, then accepting payments by having customers insert, tap, or swipe their cards. The process is straightforward once you understand the hardware setup and the three ways cards interact with the reader. Here’s everything you need to know to start accepting payments.
Connect the Reader to Your Device
Most mobile credit card readers connect to your phone or tablet in one of two ways: wirelessly through Bluetooth or with a USB cable. Bluetooth is the more common option and works with both iPhones and Android devices. To pair wirelessly, toggle Bluetooth on in your device settings, open your payment app, and navigate to the hardware or reader settings. Put the reader into pairing mode by holding its button for three to five seconds until you see flashing lights. The reader needs to be within about 10 feet of your device to connect.
If you prefer a wired connection on Android, plug one end of the included cable into the reader’s USB-C port and the other into a USB adapter that fits your phone or tablet. Wired connections to iPhones generally aren’t supported unless you’re using a countertop stand designed for that purpose. Once connected, your payment app should recognize the reader and display a “ready” indicator.
Ring Up the Sale
Before your customer pays, you need to enter what they’re buying into your point-of-sale (POS) app. Depending on your setup, you can type in a dollar amount manually, select items from a pre-built product catalog, or scan barcodes using your device’s camera. The app calculates the total, including any applicable sales tax, and presents a final amount. At that point, the customer is ready to pay.
Accept the Card Three Ways
Every modern credit card reader supports three payment methods. Which one your customer uses depends on their card and their preference.
Chip Insert (Dip)
This is the most common method for in-person transactions. The customer inserts their card chip-side up, chip end first, into the slot at the bottom of the reader. The card stays in the reader while the transaction processes, which typically takes a few seconds. A prompt on your screen or the reader itself will tell the customer when to remove the card. Pulling it out too early can void the transaction and force you to start over.
Contactless Tap
If the card has a contactless symbol (four curved lines resembling a Wi-Fi icon), the customer can hold or tap the card against the front of the reader. The same method works for digital wallets on phones and smartwatches. Tap payments use NFC (near-field communication) technology and tend to process slightly faster than chip inserts. The reader will beep or flash a green light to confirm the payment went through.
Magnetic Stripe Swipe
Swiping is the oldest method and only comes into play when a card lacks a chip or when the chip can’t be read. The customer slides the card through the groove on the side of the reader with the magnetic stripe facing the correct direction (usually toward the reader body). Most modern readers will prompt you to try the chip first and only fall back to swiping if the chip fails repeatedly.
Complete the Transaction
Once the customer’s bank authorizes the payment, your app confirms the sale is complete. You’ll typically be prompted to offer a receipt, either printed (if you have a receipt printer) or sent via email or text. Some apps also present a tipping screen before finalizing. The funds from the sale are deposited into your linked bank account, usually within one to two business days depending on your payment processor.
What It Costs Per Transaction
Every time you process a card payment, your payment processor takes a small percentage plus a flat fee. For in-person transactions, these rates vary by provider. Square charges 2.6% plus 15 cents per transaction. Chase Payment Solutions charges 2.6% plus 10 cents. Stripe charges 2.7% plus 5 cents. Providers like Helcim use a different model, charging a smaller markup (0.4% plus 8 cents) on top of interchange fees, which are the base fees set by the card networks. On a $50 sale through Square, for example, you’d pay about $1.45 in processing fees.
There’s no single cheapest option for every business. Flat-rate processors like Square are simple and predictable, which works well for businesses with lower transaction volumes. Interchange-plus processors like Helcim can save money at higher volumes but require understanding a more complex fee structure.
Fixing Common Problems
If your reader won’t connect, start with the basics: make sure Bluetooth is turned on, the reader is charged, and it’s within range. Restarting both the reader and your device resolves most pairing issues.
When a transaction freezes or the app shows “transaction sent to device” without progressing, the problem is usually internet latency. Before running the card again, check your payment processor’s online dashboard to see whether the charge actually went through. Running it a second time without checking could result in a double charge.
If the reader repeatedly rejects a card, the card itself may be expired or damaged. Ask the customer to try tapping instead of inserting, or to use a different card. When a chip read fails, most readers will eventually prompt you to swipe the magnetic stripe as a backup.
For persistent connection drops, power off the reader for 30 seconds and turn it back on. If the problem continues, restart your Wi-Fi router or check your cellular signal. A stable internet connection is essential because every transaction requires real-time communication with the payment processor to authorize the charge.