How to Take Credit Card Payments on your Website

If you run an ecommerce or any other kind of retail business, you’ll need to be able to accept and process credit card payments.

There were a huge 334.3 million credit card transactions made in the UK in February 2025 alone, according to trade association UK Finance.¹ It’s a popular way to pay, so you’ll need to make sure your business is equipped to accept cards of all kinds.

In this essential guide, we’ll give you the lowdown on how credit card payment processing works for UK businesses. This includes tips on choosing the right payment processor and getting set up.

We’ll also show you how to accept card payments online in currencies with Wise Business, which is perfect if you have customers all over the world.

💡 Learn more about Wise Business

What is credit card processing?

Credit card processing enables businesses to accept credit cards, through a series of steps involving initiation, authorisation and completion. It involves the use of a payment gateway or checkout, and a third party payment processing company which handles the transaction.

While it all may happen in a matter of seconds, it involves a number of checks - including with the customer’s bank, anti-fraud checks and other verification procedures.

As for how it works in a real-life business, let’s take the example of a busy hair salon. It may use wireless point of sale (POS) devices to process credit card payments, so that customers can make a contactless payment immediately after their appointment.

This is when all the behind-the-scenes processing steps take place. When a customer taps or swipes their card, the payment processor securely transmits the payment information from the salon’s POS system to the customer’s bank (the issuing bank) for authorisation.

Once approved, the processor facilitates the transfer of funds to the salon’s merchant account, minus a small processing fee.

It works in a similar way online, but without the need for the customer to be physically present with their credit card - instead, they’ll enter the card details on the website checkout page.

How does credit card processing work?

Let’s break down the steps involved in credit card processing:

1. The shopper enters their card details on the checkout or payment page of the website - or if in person, they’ll tap to pay or enter their card into the terminal.
2. The merchant sends a request for authorisation to the payment processor
3. The payment processor submits the transaction to the relevant card association/network (for example, Visa or Mastercard).
4. An authorisation request is made to the customer’s bank - or whichever provider issued the credit card. Details such as the CVV code, expiry date and address verification service (AVS) information is also shared at this stage.
5. The issuing bank approves the transaction - if it is declined, this may be because the customer has reached their credit limit or the account has been closed or frozen.
6. The approval is sent back through the chain until it reaches the card association and then the merchant.
7. The payment is confirmed.

It works a little differently though depending whether you’re accepting in-store or online credit card payments. Let’s take a look.

In-store credit card payment

To accept in-store credit card payments, a business needs the following:

• A merchant account with a payment processor, such as Stripe, WorldPay or Square for example. They can also provide the payment gateway software that facilitates in-person payments.
• A card machine/reader - this is also known as a point of sale (POS) terminal. There are a few different types available, including fixed terminals, mobile card readers and tables, and even options to accept payments using a compatible smartphone.

As for how this kind of setup would work in a real business, let’s take the example of a shoe shop on the UK high street.

The business would open a merchant account with a processor like Stripe, for example. They’d follow the steps to get set up with payment gateway software, and then order a countertop card reader. Once everything is online and connected to the shop’s till system, customers can easily pay using their credit cards - either contactlessly or via Chip and PIN.

To use this kind of credit card payment system, you’ll usually only pay processing fees to the payment processor. These are usually a percentage of the transaction amount plus a flat fee.

You may also pay a monthly or annual charge for your merchant account, depending on the provider. If you’re ordering a card reader, there is likely to be a charge (usually a one-off fee) for that too.

Online credit card payments

To accept credit card payments on your website, you only really need to choose the right payment processor and sign up for a merchant account. You’ll want one that offers the option to integrate a custom checkout into your website, and it’s this that customers will use to enter their card details and pay for their purchases.

This is what the vast majority of online sellers use, from major fashion brand websites to smaller independent online boutiques.

Providers which offer this include Stripe, Square, WorldPay, Adyen, WooCommerce and Revolut.

You’ll pay per-transaction processing fees, which are usually a percentage plus a flat fee. You may also have a monthly fee to pay for your account, or for add-ons such as custom checkout.

You can also accept online payments in other ways, some of which can be simpler for certain kinds of online businesses. For example, you can use Wise Business to send a payment link or QR code directly to customers. They simply enter their card details to pay.

Wise Business is a low-cost, easy-to-use solution that ensures timely payments and enhances customer satisfaction, helping you grow your business efficiently.

Get started with Wise Business 🚀

Mobile credit card payments

You can also accept credit card payments using just your phone, if it’s offered by the payment processor. This means you don’t need a card reader, only a compatible phone and an app. This can be very useful if you’re accepting payments outside of a shop, such as at a market or event.

Customers can simply tap your phone with their card (or their own phone if they have a mobile wallet or other payment app) to pay.

Per-transaction fees will apply, but you won’t need to shell out for a card reader. Popular providers offering Tap to Pay including Stripe, Square and SumUp.

How to accept credit card payments?

To start accepting credit card payments, simply follow these steps:

1. Choose a payment processor.
2. Apply for a merchant account.
3. Follow the provider’s steps to get setup, either creating a payment gateway to integrate into your website checkout or ordering a POS card reader for your bricks-and-mortar store.
4. Integrate the payment solution with your online or in-store system.
5. Carry out a few test transactions, to make sure everything is working as it should.
6. Make sure you understand the fees, and your obligations regarding security and compliance, before you start accepting customer payments.

You can also check out alternative setups. For example, you can use Wise Business to accept credit card payments in multiple currencies online, simply by sending out links, QR codes or invoices to customers.

This could be a simpler way to get paid compared to setting up a payment gateway on your website.

Get started with Wise Business 🚀

How to choose the right credit card processor?

It’s crucial to choose the right payment processor for your needs, with cost being the most important consideration. Along with fees, you should also consider:

• Reputation and reliability - check out online reviews and any available data on platform downtime
• Features - for example, you might need recurring payments if you offer subscriptions
• International card acceptance - if you have customers in other countries
• Customer support - does the company offer UK-based support, and how quickly can you get help if something goes wrong?

Simplify online payments with Wise Business

Complex payment gateway integrations are in the past, you can start accepting credit and debit card payments in currencies in minutes with Wise, no code required.

Just send a payment link, invoice, or QR code to your customers, and let Wise handle the rest, ensuring timely payments and improving your cash flow. This streamlined approach wipes out the technical challenges and time-consuming setup associated with traditional payment gateways, allowing you to focus on what truly matters: growing your business.

Say goodbye to high and complex payment processing fees. Wise Business offers a transparent, low-cost solution with just 1% fee for domestic cards and 2.9% for international and business cards.

And once the payment is done you can manage multiple currencies effortlessly, all in one account. Enhance your customer relationships and support your business's global expansion with a payment solution that prioritises simplicity and efficiency.

Get started with Wise Business 🚀

FAQs - accept payments online without a merchant account

What are the key players in credit card processing?

The main players in credit card processing are:

• The customer (cardholder)
• The merchant (the business selling the product/service)
• The issuing bank
• The card network (for example, Visa, Mastercard or American Express)
• The payment processor and payment gateway.

What are interchange fees?

Interchange fees are paid by the payment processor to the bank or provider which issued the credit card. They’re charged every time the card is used to make a purchase, and are designed to cover the card issuer's costs in handling the transaction.

As the merchant, you shouldn’t pay these fees - as they’ll usually be covered by your processing or platform fees.

How can I reduce credit card processing fees?

It pays to compare per-transaction fees carefully when choosing a payment processor, and consider looking into alternative payment methods if you still find the costs too high.

How can I accept international card payments?

Choose a payment processor which offers support for multi-currency and international payments. You can also look at alternatives such as Wise Business which allow you to accept card payments online in currencies.

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After reading this, you should have a better idea of how credit card payment processing works in the UK. We’ve looked at the steps and main players involved, along with info on how to choose a payment solution and get started.

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Sources used:

1. UK Finance - Card spending

Sources last checked on date: 30-May-2025