Which payment provider should a startup use to accept payments online?

For a typical U.S. startup, I’d start with Stripe. It’s a strong default if you’re building your own website or app: it offers a prebuilt checkout, developer tools, and support for subscriptions and marketplace payments. Standard domestic card pricing is currently 2.9% + 30¢ per successful transaction, with no setup or monthly fee. (stripe.com)

Choose something else if it fits your setup better:

• Shopify Payments if your store runs on Shopify.
• Square if you also sell in person and want online and POS payments together.
• PayPal as an additional checkout option if your customers expect to pay with PayPal or Venmo; its published online rates vary by payment type. (squareup.com)
• Adyen if you’re already processing at substantial scale and need custom pricing or more complex global operations. (adyen.com)

Bottom line: use Stripe to get started unless your platform already includes a payments provider or in-person sales are central to your business. Revisit the choice when volume, international fees, or specialized needs make pricing and approval rates worth comparing.

Short answer: for most online startups, Stripe is the default choice. The best fit still depends on your business model.

• Stripe (most online startups): Sources consistently call it the developer-friendly option. One guide says it has no monthly fees, quick account approval, and integrations with major platforms and scales from a first $100 sale to millions in annual revenue without requiring you to switch providers. It's strongest for software, subscriptions, and custom checkout flows. For pure software or digital product startups Stripe wins almost every time. Its pricing is typically quoted at about 2.9% plus $0.30 per transaction. One caveat: a Forbes review notes that the high rate of account issues is causing many users to look elsewhere.

• PayPal: A good choice if you want the fastest launch with minimal technical work. Businesses can set up accounts quickly, integrate checkout buttons with minimal technical effort, and begin accepting payments in a short timeframe.

• Square: Better if you also sell in person. The free POS app, $49 contactless card reader, and 2.6% + $0.10 in-person rate get you started quickly, and it works for non-technical founders.

• Braintree (PayPal-owned): Worth considering for marketplaces and recurring billing. One source says it leads on recurring billing.

• Helcim or Nickel: Helcim is rated for seasonal businesses and offers no setup fees and monthly volume discounts. Nickel is a fit for B2B startups that want low-cost ACH payments.

How to choose:

1. If you're building a software or subscription product, start with Stripe.
2. If you sell physical goods in person as well as online, consider Square.
3. If you need to launch without developers, consider PayPal or Square.
4. If you're a B2B company, compare ACH options such as Nickel.

Most of these sources are vendor-affiliated comparison blogs, so check current pricing directly with each provider before committing. Also check whether your country and business type are supported, since availability varies.

Choosing the right payment provider is a strategic decision that depends on your startup's business model, target geography, and technical requirements. There is no single "best" provider; instead, you should select a partner based on how well they align with your growth stage and customer needs.

Quick Recommendations

• Best for Developer-First Startups & SaaS: Stripe is the industry standard for its flexible APIs, developer tools, and ease of integration. It is highly scalable and supports a vast range of payment methods and global currencies.
• Best for Fast Setup & Trust: PayPal offers immediate recognition and trust, which can help increase conversion rates for newer, less-established brands. It is excellent for small e-commerce and service-based businesses.
• Best for European Startups: Mollie is highly regarded for its local payment method support and compliance within the European market.
• Best for Global Enterprises (Later Stage): Adyen is a powerful, enterprise-focused platform that offers deep customization and optimization for global transaction flows, though it often requires higher transaction volumes to be cost-effective.

Key Factors to Consider

Before committing to a provider, evaluate these five criteria to ensure the platform can scale with you:

1. Business Model Alignment:
   • SaaS/Recurring Revenue: Look for providers with strong "Billing" or subscription management tools (e.g., Stripe Billing, Braintree).
   • Marketplaces: If you need to pay out to multiple third parties, ensure the platform supports specialized payouts (e.g., Stripe Connect).
   • Retail/Omnichannel: If you have physical stores, look for providers that unify online and in-person payments (e.g., Square, Adyen).

1. Cost Structure:
   • Flat-Rate Pricing: Common for startups (e.g., 2.9% + $0.30). It is predictable but can become expensive as your volume grows.
   • Interchange-Plus Pricing: Often cheaper at higher volumes, this separates the card network's fee from the processor's markup, offering more transparency as you scale.

1. Geography & Payment Methods:
   • Your payment provider must support the payment methods your customers prefer (e.g., credit cards, digital wallets like Apple Pay/Google Pay, or local methods like iDEAL or UPI).
   • If you sell internationally, check the provider's currency conversion fees and how they handle cross-border settlements.

1. Integration & Technical Effort:
   • If you have a dedicated engineering team, a provider with robust APIs (like Stripe) is ideal for building a custom, seamless checkout.
   • If you are using a platform like Shopify or WooCommerce, prioritize providers with "plug-and-play" integrations to avoid custom coding.

1. Security & Compliance:
   • Ensure the provider is PCI-DSS compliant and supports necessary regional regulations (e.g., GDPR, PSD2 for Europe).

Final Advice

For most early-stage startups, starting with a "developer-friendly" aggregator like Stripe is often the safest bet. They offer the best balance of speed-to-market, documentation, and scalability, allowing you to focus on building your product rather than managing payment infrastructure. As your volume grows, you can always negotiate custom rates or explore more specialized infrastructure providers.

For a typical early-stage startup, Stripe is a strong default—especially if you’re building a custom website or app, need subscriptions, or expect to sell internationally. It offers a broad payments platform with no setup or monthly fees on standard pricing; in the U.S., domestic cards are listed at 2.9% + 30¢ per successful transaction. ¹

Consider alternatives based on how you sell:

• Square may fit better if you’ll also sell in person and want online and point-of-sale payments together. Its U.S. online API rate is listed at 2.9% + 30¢; rates can vary by plan and payment type. ²
• PayPal can be worth adding as a checkout option if your customers prefer it, but compare its fees for the specific payment method: its U.S. pricing lists card processing starting at 2.89% + 29¢, while PayPal and Venmo payments have different rates. ³

Bottom line: Start with Stripe for a software-first business; choose Square for a strongly in-person business, and consider offering PayPal alongside your main processor if customers ask for it. Fees and availability depend on your country, transaction mix, and business model, so check local pricing before deciding.