Best payment gateways for startups and alternative payment solutions

Payment gateways enable customers to pay by card at checkout. They connect your website to Visa, Mastercard, and the banks behind them. Simple enough.

But gateways aren’t your only option. Some startups don’t need checkout pages at all. If you invoice clients, receive payments from abroad, or sell to other businesses, some alternatives skip the fees that gateways charge for currency conversion.

This guide covers both. Traditional gateways like PayPal for handling cards, and alternative startup payment solutions like Wise Business for international payments and lower costs. You’ll see what each charges and how they work.

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Best payment gateway providers for startups - a comparison

Before you commit to a solution, it helps to see how they line up side by side. Each of these platforms supports e-commerce payment gateways for new businesses and small teams starting to sell online.

If your customers are mostly in the UK, any of these can do the job. But if you sell globally, the way your gateway handles currency can quietly decide your profit margins. That’s where Wise Business may help. It works alongside your gateway so you can receive, hold, and convert currencies at the mid-market exchange rate.

Factors to consider when choosing a payment gateway

Picking a payment gateway feels straightforward until you start comparing options. The advertised rates look similar, but the real cost depends on where your customers are, how they prefer to pay, and how quickly you need access to your money.

A gateway that works perfectly for a UK-based coffee shop won't suit a SaaS startup invoicing clients in five different currencies. Here's what actually matters when you're choosing.

Payment methods your customers use

Card payments are standard, but depending on your market, customers might prefer other payment methods.

In the UK, Apple Pay and Google Pay are common among consumers. If you sell to businesses, Direct Debit or invoice payments may work better than cards.

The more payment options you offer, the fewer sales you lose at checkout.

Cross-currency support

Cross-currency support is one of the most overlooked parts of online payment processing for small businesses. Most gateways add a small fee every time they convert currencies.

Some let you hold multiple currencies and convert when rates are better. Others force instant conversion at their marked-up rate. If you’re doing £20,000 a month in USD sales, poor conversion rates can quietly cost you hundreds each month.

Integration and setup

Some gateways plug straight into your existing accounting tools or ecommerce platforms. Others need developer time for API integration, which means extra cost and ongoing maintenance.

If you’re non-technical, a plug-and-play option will save you weeks of setup. Tech-heavy startups may prefer something more flexible and customisable.

Settlement speed

Cash flow matters. Most gateways take a few working days to release your funds. Some hold back your first few months of revenue as a security measure. Others charge extra for instant payouts.

If you need quick access to cover payroll or suppliers, check how long it really takes for payments to land.

Scalability

A setup that works when you’re processing £5,000 a month might not hold up when you hit £100,000. Look for platforms that can handle subscription billing, multi-currency accounts, or marketplace payments if you expect to grow. Switching providers later means re-testing your checkout and migrating saved payment details.

Security and compliance

Every gateway must comply with Payment Card Industry Data Security Standards (PCI DSS), but not all offer the same protection tools. If you’re new to online payments, built-in security can save you from expensive chargebacks.

Top payment gateways for startups

These are the e-commerce payment gateways for new businesses that handle most UK startup transactions.

PayPal

PayPal is everywhere. With up to 400 million active accounts,¹⁴ your customers are likely already using PayPal, which removes checkout friction. However, that convenience often comes with higher transaction and conversion fees.

Suitable for: Small e-commerce stores, freelancers invoicing clients, and businesses where customer trust matters more than processing costs.

Key features

• Support 200+ markets and 130+ currencies¹⁴
• Seller protection and risk management tools
• Reporting and optimisation tools built into a dashboard
• Flexible payment options.

Pricing

PayPal’s fee structure is complicated, and can be confusing. Here are the essentials you need to know:¹

Different fees apply depending on payment type, sender location, and currency. Rather than listing every scenario, use our PayPal fee calculator to see what you'll actually pay based on your transaction types.

PayPal is a globally trusted name that customers trust, which is helpful from a conversion perspective. Businesses can set up instantly with no approval wait, and money usually settles within 2-3 days.²

The biggest consideration is pricing and fee structure, particularly currency conversion as it adds another 3% in fees on international sales.¹ So, it's worth calculating if it could be more expensive than other competitors.

Mollie

Mollie is a Dutch payment gateway used by over 250,000 UK and European businesses.¹⁵ It’s one of the few gateways that lets UK startups accept iDEAL and Wero with a simple plug-in setup.

Suitable for: Startups selling into Europe who need local payment methods, not just cards.

Key features

• iDEAL, Wero and Klarna already integrated
• Supports credit/debit cards, digital wallets, bank transfers and ‘Buy Now, Pay Later’ options
• Single integration that handles multiple payment options under one contract
• Integrates with WooCommerce, Shopify, Magento
• Partners with PayPal to offer it as a payment option within Mollie’s stack.

Pricing

Mollie has no monthly fees, although businesses processing more than £50,000 per month can contact sales for custom pricing.³ For everyone else, you pay per transaction:³

Mollie also has different fees for each of the long list of payment methods it accepts - find more info here. For in-person payments, it’s also possible to join the Pro monthly plan (1 year contract). For £20/month, you’ll get lower per-transaction pricing.³

Mollie is easy to setup and businesses can cancel at anytime - there's no monthly minimum which is useful for sales flucations. Currency conversion is an aspect to consider, it could chip away at profit if you're selling in GBP - so if most of your customers aren't in Europe then it may be less suitable.

Square

US-based payments platform Square is a popular choice for UK startups. It combines online payments, point-of-sale tools and invoicing in one platform. You can accept card payments through Square Online, an existing website using its eCommerce API, or simple payment links. It also lets you take payments without a website through digital invoices or payment links.

Suitable for: Startups wanting a quick, plug-and-play way to accept online and in-person payments in the UK, without a long-term contract.

Key features

• Accept major cards and mobile wallets online and in person
• Hardware, PoS and virtual terminals
• Create payment links, buy buttons and QR codes without building a full ecommerce site
• Build a Square Online store or connect Square payments to an existing website
• Custom-tailored product suites for restaurants, retail and beauty businesses
• Integrate with ecommerce and accounting tools.

Pricing

Startups can get started with Square for no monthly fee, only processing fees (plus extras such as PoS terminals if needed). There’s also the Plus plan, which for £29/month + processing fees offers advanced features specifically for restaurants, retailers and appointment-based businesses.⁵

Businesses processing £200,000+ a year can access bespoke pricing.⁵

Here are Square’s transaction fees:⁵

Square has simple and transparent pricing - businesses can set up quickly with no long-term contract required. They also offer fast settlement, with free next-day standard payouts, with instant transfers available for an additional fee.⁶

Something to keep in mind is that it could be less cost-effective than negotiated or interchange-plus pricing once transaction volumes become very high. Startups with complex international payment needs may want to consider a separate solution for managing multiple currencies and reducing conversion costs.

SumUp

UK company SumUp is a flexible payments platform aimed at small businesses and startups. As well as card readers and in-person payments, it offers online payment links, a free online store, and payment gateway integrations for websites and ecommerce platforms. You can also integrate SumUp into a custom website or app using its API or payment widget.

Suitable for: UK startups wanting to accept in-person, on-the-go payments, with some e-commerce website tools and PAYG options.

Key features

• Accept Visa, Mastercard, American Express, Apple Pay and Google Pay, plus multiple local payment methods depending on your market
• Payment links
• Build a free SumUp Online Store, or use the API/widget for a custom website
• Integration with e-commerce platforms such as WooCommerce and Wix
• PoS hardware and tools for in-person payments, plus online payments and invoicing.

Pricing

SumUp fees are pretty simple and straightforward - let’s take a look:⁷

SumUp has simple, flat pricing with PAYG options and supports both online and in-person payments. Its free online store makes it easy for very small businesses to start selling online. However, online payment fees are higher than some other providers and is generally less customisable for international payment flows than some competitors. Some advanced integrations require API development rather than a simple plug-in.

Worldpay

US-based Worldpay is a major name in the world of global payment processing. For UK startups, scaleups and large businesses, it offers a full range of online and in-person payment solutions. Its Worldpay eCommerce product lets businesses accept card payments online, as well as digital wallets and other payment methods, through integrations with platforms such as Shopify and WooCommerce.

Suitable for: Scaling up ecommerce startups wanting a recognised payment provider, fast settlement and the option to scale into international markets.

Key features

• Accept payments in 110+ currencies from all major cards, digital wallets and a range of other methods⁹
• Ready-to-use plugins for ecommerce platforms including Shopify and WooCommerce
• Payment links, invoices and QR codes
• Hosted checkout, embedded components and APIs for more customised integrations
• Built-in fraud protection
• Multi-currency pricing.

Pricing

Here are Worldpay’s fees for accepting online payments:⁹

Custom pricing is also available for businesses with large transaction volumes. For many of its services, Worldpay tailors its pricing to the specific customer - so you may need to contact the sales team for a quote.

Worldpay has has fast next-working-day settlement, with support for a wide range of payment methods and currencies too. Businesses do not have to pay a setup or monthly fee on the PAYG eCommmerce plan, which provides flexibility. And, ready-made Shopify and WooCommerce integrations make setup easier. However, a consideration is that pricing can become more complex once you move beyond the standard pay-as-you-go plan.

Adyen

Adyen is a global payments platform used by large online and omnichannel merchants. It’s built from the ground up as an enterprise-grade payment processor and gateway. It’s serving companies like Spotify, Uber, and eBay with unified online, in-store, and mobile payments. However, it can also be useful for rapidly scaling startups anticipating a significant uptick in sales volume.

Adyen’s strength lies in offering many payment methods and currencies through a single integration, with transparent pricing based on payment type and region.

Suitable for: Mid-to-large ecommerce businesses and global enterprises needing flexible international payment acceptance and unified reporting.

Key features

• Accept payments online, in-store, and on mobile through one platform
• Support for 200+ payment methods and multiple currencies¹⁶
• Flexible payouts with control over settlement currency and timing
• Omnichannel risk and fraud management.
• Developer-friendly APIs and ready-made integrations.

Pricing

Adyen’s pricing is pay-per-transaction with no setup or monthly fees. It uses an Interchange++ model. This is a fixed processing fee plus the payment method/scheme fees.¹⁰

Typical UK pricing examples:¹⁰

Rates with Adyen also vary by payment method and sector/volume and often require a sales quote for precise pricing.

Adyen works well for businesses who enjoy a pay per transaction model, with no recurring monthly or setup fees. It's one integration for online + POS + mobile + marketplaces too. Businesses can make the most of a highly customisable gateway suitable for complex e-commerce needs, with extensive global and local payment method support.

However, pricing isn’t as simple or predictable as flat-rate processors (depends on Interchange++). And, it might require a sales contact to get exact pricing and contract terms.

Shopify Payments

Shopify Payments is Shopify’s built-in payment processing solution. It’s automatically integrated into your Shopify store, so you don’t need a separate gateway. Payment processing, checkout, orders, and payouts are all managed in one dashboard. Because it’s native to Shopify, you avoid extra third-party gateway fees and can keep everything under one platform.

Suitable for: Ecommerce businesses (small to enterprise) that want an integrated store plus payments without a separate payment provider setup.

Key features

• Accept card payments directly in your Shopify checkout with no third-party gateway setup.
• Integrated dashboard for orders, payouts, and payment reporting.
• Works in-store with Shopify POS terminals and online checkout.
• Supports major cards (Visa, Mastercard, Amex) and local payment methods (e.g., digital wallets, BNPL where available).
• Automatic syncing of sales and inventory across channels.

Pricing

Shopify Payments itself has no separate setup or monthly fee. You just pay the monthly Shopify plan fee plus transaction processing fees.

Here’s the breakdown:¹²

Shopify also has separate fees for other payment methods, such as Klarna, iDEAL and TWINT for example - see full details on Shopify’s pricing page.

With Shopify, businesses get access to one unified dashboard for store + payments + checkout, it's a great plug-and-play solution that's easy to set up. There's also no extra monthly payment gateway fee beyond your Shopify plan.

However, payment processing rates are tied to your Shopify plan - lower-tier plans pay higher per-transaction rates. Some advanced merchant features (e.g. custom-negotiated rates) are only available on Plus or through volume negotiation.

Consider Wise Business as a payment solution for your startup

If your startup sells overseas, you probably know how much banks and gateways take when they convert your payments. A few percent here and there adds up quickly. Wise Business is built to solve that problem.

You can use Wise Business if you collect payments from customers directly, although the Wise ecommerce payment gateway is also coming soon.

Open a Wise Business Advanced account (for a one-time fee of £50) and you’ll receive local details for 8+ major currencies including EUR, USD and CAD. Customers can pay you in their own currency using these account details.

You can use your account’s request payment feature to send customers a Wise payment link so they can pay you easily. Wise Business also provides invoicing tools to create professional invoices. These contain your Wise payment details, making it easy for customers to pay you.

With Wise Business, you can:

• 🌍 Send money to 70+ countries and pay overseas invoices at the mid-market exchange rate with low, transparent fees and no hidden exchange rate markups (product availability varies by region)
• 📥 Receive payments in 24 currencies and counting
• 💵 Get local account details for 8+ currencies, including USD and EUR, to let your customers pay in a currency they know and trust - convenience for them and peace of mind for you
• 💰 Hold money in 40+ currencies
• 🔁 Convert currencies anytime at the mid-market exchange rate with low, transparent fees
• ⚡ Use the batch payments tool to create and send up to 1,000 payments in a single transfer
• 👥 Run payroll and make international payments for up to 1,000 employees all over the world - including paying suppliers using local payment methods like ACH, SEPA, and Faster Payments
• 💳 Get business debit cards with 0.5% cashback for you and your team to keep track of team expenses and spend all over the world, with real-time visibility and categorisation. See full cashback terms and conditions
• 🏢 Manage cash in 55+ currencies across international offices from a single business account and move money between business accounts in seconds (exact speeds can vary depending on individual circumstances and may not be the same for all transactions)
• 🧾 Connect and sync every business transaction to your favourite accounting software, including Xero, Quickbooks, and more
• 🔐 Create your own payment approvals process to manage your team better with customised access for different team members, roles and permissions
• 📑 Create custom professional invoices and schedule invoice payments for future dates
• 📈 Earn variable returns on GBP, USD and EUR with Wise Interest (Growth not guaranteed. Your balance will go down in the event of a government default or interest rates going negative.)
• 🔗 Create payment links and QR codes to get paid easily (Card payment acceptance for new Wise Business customers is currently unavailable. Payment methods subject to eligibility and availability.)
• ⚙️ Automate payouts with the Wise API (comes with 24/7 customer support, a sandbox account to test integrations, API tokens, and clear documents on how to implement and make the most of our API)

Make the wise choice when selecting a business account for your domestic and global needs.

Be Smart, Get Wise.

Register for Wise Business ✍️

FAQs

What is the cheapest payment gateway for a startup?

Fees change depending on how your customers pay and where they are. Card networks, international sales, and currency conversion all add costs. The best option is the one that keeps your total fees low once everything’s included. Many startups use Wise Business alongside a gateway to cut conversion costs when customers pay from abroad.

How do startups accept payments?

Most use an online gateway that connects their website to card networks. Others send invoices or payment links instead. If your customers are overseas, combining a gateway with Wise Business can make international transfers simpler and cheaper.

Can I use multiple payment gateways at once?

Yes, and many startups do. You might choose one platform for card payments, another for subscriptions, and Wise Business for international invoices. The main challenge is reconciliation. Connect each gateway to your accounting software (such as Xero or QuickBooks) to automate tracking across platforms.

Sources

1. PayPal - PayPal Merchant Fees
2. PayPal - Settlement
3. Mollie - Pricing
4. Mollie Dev - Balance
5. Square - Pricing
6. Square - Square Payout Options
7. SumUp - Pricing
8. SumUp - Support - Payouts: How do I get my money?
9. Worldpay - WorldPay eCommerce
10. Adyen - Pricing
11. Adyen Docs - Payouts
12. Shopify - Pricing
13. Shopify - Help - Understanding Shopify Payments payout timing
14. PayPal - Business (no of accounts, currencies)
15. Mollie - Home
16. Adyen - Accept payments

Sources last checked: 08-Sep-2026