UK Payment Gateways Compared: Which Is Right for Your Online Store?

What Does a Payment Gateway Actually Do?

A payment gateway is the technology that securely transmits a customer's card details from your website to the payment processor, and back again with an approval or decline. It sits invisibly between your checkout page and the banking networks, encrypting sensitive data, communicating with the customer's card issuer, and returning an authorisation result — all in a matter of seconds.

Some providers bundle the gateway, payment processor, and merchant account into a single product (Stripe and PayPal work this way). Others, like Worldpay, operate as a gateway that connects to a separate merchant account you hold with a bank. Understanding this distinction matters because it affects your pricing structure, your risk of fund holds, and how quickly you receive your money.

UK-Specific Considerations Before You Choose

Strong Customer Authentication (SCA) and 3DS2

Since the UK's implementation of Strong Customer Authentication — part of the Payment Services Directive 2 — most online card transactions over £25 now require two-factor verification from the customer. This is handled through 3D Secure 2 (3DS2), which adds a frictionless or challenge-based authentication step at checkout. Every payment gateway operating in the UK must support 3DS2. However, the quality of implementation varies significantly: a poorly integrated gateway can trigger unnecessary friction and increase cart abandonment, while a well-tuned one handles most transactions invisibly through "frictionless flow" exemptions.

FCA Regulation

Payment service providers operating in the UK must be authorised or registered with the Financial Conduct Authority (FCA). Before committing to any provider, verify their FCA registration on the Financial Services Register. This protects you and your customers, and is a basic due diligence step that is often skipped.

Stripe

Best for: startups, developers, and businesses that want full control over their checkout experience.

Stripe is the developer's gateway of choice, and for good reason. Its API is best-in-class, its documentation is exceptional, and its product suite has expanded far beyond payments to include invoicing, subscriptions, tax calculation, and fraud prevention (Stripe Radar). Standard UK pricing is 1.5% + 20p per successful card transaction for UK cards, rising to 2.5% + 20p for EEA cards and higher for other international cards.

Stripe's 3DS2 implementation is sophisticated, using machine learning to request authentication only when risk signals suggest it is necessary. Stripe Radar, included in the base price, uses transaction data from millions of businesses to block fraudulent payments before they happen. The main caveat: Stripe's power comes with complexity. Non-technical teams may find the dashboard less intuitive than alternatives, and building a fully custom checkout requires developer resource.

PayPal

Best for: businesses with a customer base that values PayPal's buyer protection, or those selling internationally.

PayPal remains the most recognised online payment brand in the UK. Its primary value proposition is trust: a significant portion of online shoppers — particularly those aged 35 and above — feel more comfortable completing a purchase when PayPal is available. Offering PayPal as a payment option alongside card payments can meaningfully improve conversion for this demographic.

Standard transaction fees are 2.99% for domestic transactions (with no fixed fee for checkout payments), though this varies by plan and monthly volume. PayPal's fraud protection (PayPal Seller Protection) covers eligible transactions against chargebacks and reversals, which is valuable for physical goods sellers. The downsides are a less elegant checkout experience, occasional fund holds for new or high-risk sellers, and customer service that can be slow to resolve disputes.

Shopify Payments

Best for: businesses already on the Shopify platform who want the simplest possible setup.

If your store runs on Shopify, Shopify Payments is almost always the most cost-effective choice. It is powered by Stripe under the hood, so the technical quality is high, but it is deeply integrated into the Shopify admin — no separate gateway account, no third-party setup, and unified reporting across sales and payments. Transaction fees range from 2% on the Basic plan down to 0.5% on the Advanced plan, applied on top of the card processing rate. Critically, using any other payment gateway on Shopify incurs an additional transaction fee of up to 2%, making Shopify Payments essentially the default unless you have a specific reason to use an alternative.

Worldpay

Best for: established mid-to-large businesses processing high volumes, particularly those with complex needs or existing banking relationships.

Worldpay (now part of FIS) is the largest payment processor in the UK and processes a substantial share of all UK card transactions. It offers enterprise-grade reliability, strong fraud management tools, and support for a very wide range of payment methods and currencies. Pricing is typically negotiated based on volume, making it less competitive for small businesses but potentially very attractive at scale. Worldpay is also a strong choice for businesses that need to accept payments across physical and online channels from a single provider.

The trade-off is that Worldpay's contract terms, setup complexity, and customer support have historically drawn criticism. Read any contract carefully, paying attention to minimum monthly fees, early termination charges, and PCI non-compliance fees.

Klarna and Buy-Now-Pay-Later Options

Klarna is not a replacement payment gateway — it is a financing layer that sits alongside your existing gateway. Offering Klarna (or competitors such as Clearpay or Laybuy) allows customers to split payments into instalments or pay up to 30 days later, with Klarna paying you the full amount upfront.

The impact on conversion can be substantial, particularly for higher-value items. Studies have consistently shown that adding BNPL options at checkout increases average order value and reduces basket abandonment for purchases in the £50–£500 range. The cost to the merchant is typically 2–6% per transaction depending on the product used — higher than standard card fees, but often justified by the uplift in completed sales. Be aware that the FCA has been moving towards tighter regulation of BNPL products; ensure any BNPL provider you work with is or will be FCA-authorised.

PCI DSS Compliance: The Basics

The Payment Card Industry Data Security Standard (PCI DSS) is a set of security requirements that every business handling card data must meet. The level of compliance required depends on your transaction volume and how you handle card data. Using a hosted payment page or an embedded checkout from Stripe, PayPal, or Shopify Payments significantly reduces your compliance burden — card data never touches your server, so you fall into the lowest compliance tier (SAQ A), which involves completing a self-assessment questionnaire annually. Storing card data yourself, or building a fully custom integration that transmits raw card numbers, escalates compliance requirements dramatically and is not recommended without specialist guidance.

How to Choose Based on Your Business Type

• New or small store (under £10k/month): Stripe or PayPal for simplicity and no monthly fees; Shopify Payments if you are on Shopify
• Growing store (£10k–£100k/month): Stripe with Radar for fraud control; consider adding Klarna for higher-value product categories
• Established business (£100k+/month): negotiate a volume deal with Worldpay or Stripe; implement a full BNPL suite; invest in professional 3DS2 optimisation to reduce friction
• Subscription-based business: Stripe Billing or GoCardless for direct debit; both handle recurring billing, failed payment retry logic, and dunning automatically
• Marketplace or multi-vendor store: Stripe Connect is purpose-built for splitting payments between multiple sellers

Final Thoughts

Your payment gateway is not a set-and-forget decision. As your store grows, your transaction mix evolves, and the regulatory landscape in the UK continues to shift, your payment stack deserves the same attention as your marketing or inventory strategy. If you are building or re-platforming an e-commerce store and want to make sure your checkout is optimised for both conversion and compliance, the team at Thind Global Services can help you architect the right solution from day one.