NMI vs Stripe UK 2026: Fees, Features & Which to Choose

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NMI and Stripe are two very different types of payment technology business. NMI is a white-label payment gateway built for independent software vendors (ISVs), payment facilitators, and resellers who need to embed payments into their own platforms. Stripe is a direct-to-merchant payment processor aimed at developers and businesses that want a fully self-managed setup. In the UK, Stripe suits startups, e-commerce brands, and growing businesses that want fast self-service onboarding. NMI suits technology companies and resellers building payment products for others rather than processing payments directly themselves.

NMI vs Stripe: Fee Comparison

What is NMI?

NMI (Network Merchants Inc) is a US-based payment gateway founded in 2001 that specialises in white-label payment infrastructure. Rather than selling directly to merchants, NMI provides its gateway technology to ISVs, independent sales organisations (ISOs), and payment facilitators who then resell it under their own brand or integrate it into their own software platforms. In the UK, you are unlikely to encounter NMI directly. You are more likely to use it without knowing, through a software platform or payment reseller that has built its product on NMI's technology.

NMI supports card-present and card-not-present transactions, recurring billing via its Customer Vault, and connections to over 200 acquiring banks and processors worldwide. Because NMI is a gateway rather than an acquirer, it does not hold or settle your funds. That role falls to whichever acquiring bank your reseller or platform has connected. This structure gives ISVs a great deal of flexibility but adds a layer of complexity for merchants who want to understand exactly who they are dealing with and what their total cost will be. You can read more on the NMI provider review page.

What is Stripe?

Stripe is a US-founded payment processor launched in 2010 that operates as a payment service provider (PSP) rather than a traditional acquirer. In the UK, it is one of the most widely recognised payment platforms for online businesses. Stripe handles the full payment stack: the payment gateway, merchant account, fraud tooling, and payouts. Merchants sign up directly on stripe.com, complete identity verification online, and can typically start accepting payments the same day. Its developer-first API has made it a default choice for technology-led businesses building custom checkout experiences.

Stripe's UK pricing is tiered by card type rather than a single flat rate. UK consumer Visa and Mastercard cards cost 1.5% per transaction online, European cards cost 2.5%, and non-European cards cost 3.25% plus 30p. American Express attracts a separate rate of 2.5% for UK-issued cards. Stripe also offers Stripe Terminal for in-person payments, Stripe Billing for subscriptions, and Stripe Radar for fraud prevention. Account stability can be a concern for higher-risk or unusual business types, with some merchants reporting sudden fund holds. You can read more on the Stripe provider review page.

NMI vs Stripe: Features Compared

Payment Methods

Stripe accepts a wide range of payment methods out of the box. These include Visa, Mastercard, American Express, Apple Pay, Google Pay, BACS Direct Debit, and buy now pay later options via Klarna and Afterpay. You enable most of these from the Stripe Dashboard without writing any additional code. NMI supports card payments, ACH in the US, and digital wallets, but the specific payment methods available to a UK merchant depend heavily on which acquirer and reseller has set up the account. There is no single published list of UK-available methods because NMI is configured differently for each partner.

Hardware and Terminals

Stripe sells its own card reader hardware under the Stripe Terminal brand. The BBPOS WisePOS E costs around £199 and supports chip and PIN, contactless, and Apple Pay in-person. Setup is handled through the Stripe Dashboard and the Terminal SDK. NMI also supports card-present transactions and integrates with a broad range of third-party terminal hardware, including devices from Ingenico and Verifone. However, terminal sourcing through NMI happens via your reseller rather than directly, so hardware options, pricing, and support arrangements vary considerably.

Integrations

Stripe integrates natively with Shopify, WooCommerce, Magento, Squarespace, Wix, and hundreds of other platforms. It offers pre-built plugins, a well-documented REST API, and a hosted checkout page called Stripe Checkout that requires minimal development work. NMI provides API integrations for custom builds and connects to a wide range of POS systems and shopping carts, but the integration experience is generally aimed at developers working within a reseller's ecosystem rather than merchants self-serving. If you want to go live quickly without a developer, Stripe is considerably simpler.

International Support

Stripe supports businesses in 46 countries, accepts payments in over 135 currencies, and automatically converts foreign currency at its own exchange rate with a 2% conversion fee on top. UK businesses selling internationally will find multi-currency support straightforward to configure. NMI connects to acquirers across more than 200 countries and is designed for platforms that need to serve merchants in multiple territories. For a UK-based ISV building a global payments product, NMI's multi-acquirer architecture offers genuine flexibility. For a single UK merchant selling abroad, Stripe is the more practical choice.

Fraud Tools

Stripe Radar is included in all accounts and uses machine learning trained on transaction data across millions of businesses. It blocks suspicious transactions automatically and allows you to write custom rules, for example blocking all cards issued outside Europe. Advanced Radar features are available on Stripe Radar for Fraud Teams at 5p per screened transaction. NMI includes its own fraud filtering tools within the gateway, covering velocity filters, IP blocking, card verification checks, and CVV and AVS matching. The quality of NMI's fraud tooling varies depending on which version of the gateway your reseller has deployed.

Customer Support

Stripe offers 24/7 support via email and live chat, with phone support available on Stripe Plus. The documentation is thorough and the developer community is large, which means most technical questions have a publicly available answer. Support quality can dip during high-traffic periods and account reviews can feel opaque if your account is flagged. NMI does not offer direct merchant support. If you are using NMI through a reseller, your first point of contact is that reseller. Response times depend entirely on who you are buying through. This is a genuine weakness for merchants who need a direct line to technical support.

Pros and Cons

NMI Pros and Cons

Pros

• White-label architecture lets ISVs and resellers build fully branded payment products without building gateway infrastructure from scratch
• Connects to over 200 acquiring banks globally, giving platforms flexibility to work with multiple acquirers for redundancy or regional coverage
• Customer Vault tokenises and stores card data on NMI's servers, removing PCI scope burden from the merchant or platform
• Supports both card-present and card-not-present transactions in a single gateway, useful for omnichannel software platforms
• Interchange-plus pricing is available through many resellers, which can be cheaper than blended rates at higher volumes

Cons

• No direct merchant onboarding. UK businesses cannot sign up with NMI themselves you must go through a reseller or ISO, which adds friction and cost
• Pricing is entirely opaque. There are no published rates, so comparing costs against other providers requires getting multiple quotes through intermediaries
• Support for individual merchants is non-existent at the NMI level. You depend on your reseller for help, which can be a serious problem if that relationship breaks down
• Contract terms including lock-in periods and early termination fees are set by the reseller, not NMI, and can vary widely

Stripe Pros and Cons

Pros

• Transparent, published pricing with no monthly fee and no minimum contract you pay 1.5% per UK consumer card transaction online and nothing else on the standard plan
• Same-day onboarding in most cases, with no paperwork and instant access to the Dashboard after identity verification
• One of the most developer-friendly APIs available, with clear documentation, SDKs for most major languages, and an active developer community
• Broad payment method coverage including Apple Pay, Google Pay, BACS Direct Debit, Klarna, and over 135 currencies, all managed from one dashboard
• Stripe Radar fraud detection is included in the standard plan at no extra cost, using data from millions of global businesses

Cons

• Account stability is a real concern. Stripe can place sudden holds on funds or suspend accounts with limited notice, particularly for businesses in higher-risk sectors
• Non-European card fees of 3.25% plus 30p per transaction are high, and the 2% currency conversion fee adds cost for UK merchants with significant overseas sales
• Phone support is only available on Stripe Plus, which starts at $500 per month in USD. Standard plan users rely on email and live chat
• Stripe operates as a PSP rather than a dedicated merchant account, which means your funds share infrastructure with other merchants and disputes can take longer to resolve

Which is Better For...?

ISVs and Payment Resellers

NMI is the stronger choice here. If you are building a software platform that needs embedded payments, or if you are an ISO reselling payment services under your own brand, NMI's white-label gateway gives you the infrastructure to do that without building from scratch. Stripe Connect offers a similar reseller model, but NMI has deeper acquirer connectivity and more established relationships with the ISO community. For UK software companies building payment products for other merchants, NMI is worth investigating through a registered reseller.

Online E-commerce Merchants

Stripe wins clearly for direct e-commerce businesses. A UK Shopify or WooCommerce store can integrate Stripe in under an hour, accept UK consumer cards at 1.5% per transaction, and manage everything from one dashboard. NMI is not practically accessible to a standalone online merchant without going through a reseller, which adds cost and complexity. Unless your reseller is offering materially better rates than Stripe's published pricing, Stripe is the simpler and more cost-effective option for most online retailers.

High-Volume Merchants

At high volumes, Stripe's blended pricing becomes expensive relative to interchange-plus alternatives. A business processing £500,000 per month online pays Stripe approximately £7,500 in transaction fees on UK consumer cards alone, before accounting for European or non-European card traffic. At that volume, interchange-plus pricing through a dedicated acquirer will almost always be cheaper. NMI's gateway, paired with a competitive acquiring contract, could deliver a lower overall cost. High-volume merchants should get quotes from both routes and compare total cost of ownership, not just the headline rate.

Startups and Low-Volume Businesses

Stripe is the right starting point. There is no monthly fee, no contract, and no minimum volume. A business processing £5,000 per month pays around £75 in transaction fees on UK consumer cards. NMI requires a reseller relationship, a separate acquiring contract, and typically a monthly gateway fee of £10 £25. The fixed cost structure makes NMI uneconomical at low volumes. Stripe's pay-as-you-go model means your payment costs scale directly with your revenue until the point at which a negotiated rate makes sense.

Our Verdict

NMI and Stripe are not direct competitors in the way that Stripe and Square are. NMI is gateway infrastructure for payment businesses. Stripe is a payment service for merchants. Comparing them directly only makes sense if you are a software platform or reseller deciding which technology to build on, or if a reseller has pitched you NMI-based pricing and you want to know how it stacks up against going directly to Stripe.

For the vast majority of UK merchants, Stripe is the more accessible and transparent option. The published pricing, no-contract model, and same-day onboarding remove a great deal of friction. NMI makes sense when you need white-label payment infrastructure, multi-acquirer connectivity, or when a reseller can offer genuinely better interchange-plus rates than Stripe's blended pricing at your specific volume. The catch is that those savings are only visible once you have a quote, because NMI publishes nothing.

If you are unsure which route offers better value for your business volume and card mix, Compare Card Fees is a free, independent advisory service that has helped UK businesses find better card payment deals since 2012. Use the Compare Card Fees comparison tool to get quotes from multiple providers and see your actual costs side by side before committing to either.