NMI, Stripe and Adyen serve three different Shopify merchant profiles. Stripe is the mainstream default — fastest onboarding, cleanest APIs, tightest category list. Adyen is the enterprise choice — better global coverage, cross-border optimization, meaningful presence at scale, and a high-risk desk that some verticals need. NMI is the whitelabel platform behind dozens of high-risk-friendly resellers — the practical choice when Stripe and Adyen have both said no to your category. Picking one is really picking your risk profile and your growth corridor.
Stripe: default until it isn't
Stripe is the payment API operators reach for first because everything ships fast. Test-mode keys in minutes. Documentation that developers actually read. A Shopify Payments backend that is Stripe under the hood in most regions, so the primary experience is the same rail. Card-approval rates on mainstream categories are competitive with anyone.
The catch is the category list. Stripe has a well-defined restricted-and-prohibited list. Kratom, CBD, delta-8, adult, most peptide, some supplement, IPTV, dropshipping past chargeback thresholds — all on it. Stripe accounts in restricted categories get flagged fast, usually inside the first month, and terminations are hard to reverse.
Best fit: mainstream DTC (apparel, homeware, electronics, non-consumable), SaaS, agency work, digital services with clean categories.
Adyen: enterprise-grade, sometimes high-risk-friendly
Adyen is the payment platform for large multi-country retailers — H&M, Uber, Booking. On Shopify Plus it appears as a native integration for merchants above certain volume thresholds. The strength is cross-border approval rates, local acquiring in specific corridors, and Adyen's own real-time analytics on decline reasons.
Onboarding is the friction. Adyen underwrites merchants directly for their main product, but they also run a high-risk desk that handles verticals the main product will not. Getting onto the high-risk desk requires a real conversation with Adyen sales, KYC that takes weeks, and volume commitments that make sense at $500K+/month.
Best fit: multi-country brands with real corridor complexity, high-volume subscription businesses, merchants where a specific European or APAC market matters, high-risk operators large enough to get through Adyen's high-risk onboarding.
NMI: the whitelabel platform behind resellers
Network Merchants Inc (NMI) does not sell directly to most merchants. Instead, dozens of high-risk-friendly gateways (Fluid Pay, iTransact, Payment Cloud, Payline, Instabill, etc.) use NMI's platform under the hood. When a merchant "gets an NMI MID," they are usually getting a reseller's MID that connects through NMI's API surface.
The advantage is category coverage. NMI resellers underwrite kratom, delta-8, THCA hemp, peptides, vape, adult, IPTV, high-chargeback subscriptions — categories Stripe would not touch and Adyen would not accept without enterprise-scale volume. Approval times are days to weeks depending on the reseller. Pricing is higher than Stripe or Adyen (3-5% + 0.30 is typical) reflecting the risk.
Best fit: high-risk verticals, operators who have already been declined by Stripe or Shopify Payments, merchants who need same-week onboarding, US-focused stores where offshore acquiring is not required.
The three-way comparison
Pricing: Stripe cheapest for mainstream (2.4-2.9%). Adyen cheapest at scale on Interchange++ pricing. NMI/reseller most expensive but only option for many verticals.
Onboarding time: Stripe minutes. NMI reseller days to a week. Adyen weeks.
Category coverage: NMI reseller widest. Adyen high-risk desk medium. Stripe narrowest.
Global corridors: Adyen strongest. Stripe good in North America and Europe. NMI mostly US-focused.
Documentation and developer experience: Stripe best. Adyen good. NMI reseller varies wildly by reseller.
Ban risk on your category: Stripe highest. Adyen medium. NMI/reseller lowest, because the reseller already underwrote your vertical.
The multi-gateway answer
Realistic scaled operators do not pick one of the three; they pick two and put them behind a routing layer. Stripe as route 1 for the cheapest possible capture on card networks that like your MCC. NMI reseller as route 2 for when Stripe declines a transaction the reseller would approve. Adyen as route 3 if there is real international exposure. When one route dies mid-scale, the cascade rotates without buyer impact.
Related reading: NMI Shopify checkout · Payment gateway cascade · All integrations
Wire two of the three behind a cascade.
Own-domain checkout, routing under 400ms.