License & Deployment Mix: 14 tools – 2 OSS, 12 SaaS. (OSS and SaaS counts can overlap when an open-source tool also offers a vendor-hosted edition.)
What Is Payment Processing?
Payment processing is the technology and service infrastructure that enables businesses to accept, route, and settle electronic payments from customers. It encompasses credit and debit card transactions, bank transfers (ACH, SEPA, BACS), digital wallets (Apple Pay, Google Pay), buy-now-pay-later (BNPL), and alternative payment methods across currencies and geographies.
Payment processing is the critical link between a customer’s intent to pay and the business receiving funds. Without it, online commerce, subscription billing, and recurring revenue models are impossible. The payment stack handles authorization, fraud detection, settlement, refunds, disputes (chargebacks), and regulatory compliance (PCI DSS, SCA, KYC/AML) in real time.
Modern payment platforms provide:
- Card processing – accept Visa, Mastercard, Amex, Discover, and regional card networks; real-time authorization and capture; support for card-present (POS terminal) and card-not-present (online) transactions
- ACH / SEPA / BACS – bank-to-bank payment rails for direct debit and credit transfers; lower fees than card networks; settlement in 1–3 business days; ideal for recurring billing and B2B payments
- Recurring billing – subscription management with trial periods, proration, plan changes, dunning (failed payment retry), metered/usage-based billing, and revenue recognition
- Invoicing – generate, send, and track invoices; accept online payment against invoices; integrate with accounting systems for reconciliation
- Multi-currency – accept payments in local currencies; automatic currency conversion; settlement in preferred currencies; FX rate transparency
- Refunds and disputes – process full and partial refunds; manage chargeback disputes with evidence submission; fraud detection and prevention
- Payouts – distribute funds to marketplace sellers, contractors, or affiliates; split payments; multi-party settlement
- Compliance – PCI DSS compliance (tokenization, hosted payment pages); Strong Customer Authentication (SCA / 3D Secure) for European regulations; KYC/AML verification for merchant onboarding
The information on these pages was researched by a combination of human review and large language models. To suggest an addition or correction, please contact us. Prepared by Rhodium Systems Inc., author of the ResorsIT platform — a unified IT operations management platform for IT teams and MSPs that integrates a curated suite of open-source, commercial, and SaaS applications into a single system with shared identity, single sign-on, access control, and a common audit trail. Use this catalogue only as a starting point for your own research, and review any tool carefully against your own requirements before relying on it. Catalogue data version 2026.197.
Comparison
This evaluation covers the full payment processing landscape – gateways, subscription billing, and merchant-of-record platforms across OSS and commercial SaaS.
SSO / OIDC Comparison
OIDC is the preferred SSO protocol.
| Tool | OIDC | SAML | SCIM | Authentik Notes |
|---|---|---|---|---|
| Kill Bill | No | No | No | No built-in SSO; dashboard access via reverse proxy (Authentik proxy provider) |
| Lago | No | No | No | No built-in SSO; API-first; dashboard access via reverse proxy |
| Stripe | No | Yes (Dashboard SSO) | Yes (Team management) | SAML SSO for Stripe Dashboard (requires Stripe Scale or custom plan); Authentik as SAML IdP |
| Square | No | Yes (Enterprise) | No | SAML SSO for Square Dashboard (enterprise plans); Authentik as SAML IdP |
| PayPal / Braintree | No | Yes (Enterprise) | No | SAML SSO for Braintree Control Panel (enterprise); Authentik as SAML IdP |
| Adyen | No | Yes | Yes | SAML SSO for Adyen Customer Area; SCIM provisioning; Authentik as SAML IdP |
| Authorize.Net | No | No | No | No SSO; username/password login only; multi-user accounts with permissions |
| Mollie | No | No | No | No SSO; email-based login; team member invitations with roles |
| Paddle | No | Yes (Enterprise) | No | SAML SSO for Paddle Dashboard (enterprise plans); Authentik as SAML IdP |
| Chargebee | Yes | Yes | Yes | Native OIDC and SAML; SCIM provisioning; Authentik as IdP |
| Recurly | No | Yes | No | SAML SSO for Recurly Dashboard; Authentik as SAML IdP |
| GoCardless | No | Yes (Enterprise) | No | SAML SSO for GoCardless Dashboard (enterprise plans); Authentik as SAML IdP |
| Checkout.com | No | Yes | No | SAML SSO for The Hub dashboard; Authentik as SAML IdP |
| Wise Business | No | No | No | No SSO; email + 2FA login; team member roles via invitation |
Best SSO support: Chargebee (OIDC, SAML, SCIM), Adyen (SAML, SCIM)
No SSO: Kill Bill, Lago, Authorize.Net, Mollie, Wise Business (no native SSO; reverse proxy or direct login only)
API Comparison
| Tool | API Type | Auth | Webhooks | SDKs |
|---|---|---|---|---|
| Kill Bill | REST | API key + secret | Yes (push notifications) | Java (official), Ruby, Python, PHP, Go (community) |
| Lago | REST + GraphQL | Bearer token | Yes (webhooks) | Ruby (official), Python, Node.js, Go (community) |
| Stripe | REST | API key (secret + publishable) | Yes (webhooks, extensive events) | Python, Ruby, Node.js, Go, Java, .NET, PHP (all official) |
| Square | REST | OAuth2, API key | Yes (webhooks) | Python, Ruby, Node.js, Java, .NET, PHP (all official) |
| PayPal / Braintree | REST | OAuth2 (PayPal), API key (Braintree) | Yes (webhooks, IPN) | Python, Ruby, Node.js, Java, .NET, PHP (all official) |
| Adyen | REST | API key + HMAC | Yes (webhooks, extensive) | Python, Ruby, Node.js, Go, Java, .NET, PHP (all official) |
| Authorize.Net | REST + XML | API login ID + transaction key | Yes (webhooks) | Python, Ruby, Node.js, Java, .NET, PHP (all official) |
| Mollie | REST | API key (test + live) | Yes (webhooks) | Python, Ruby, Node.js, Go, PHP (official) |
| Paddle | REST | API key + secret | Yes (webhooks, extensive) | Python, Node.js, PHP, Go (official) |
| Chargebee | REST | API key (site-specific) | Yes (webhooks, events API) | Python, Ruby, Node.js, Go, Java, .NET, PHP (all official) |
| Recurly | REST | API key | Yes (webhooks) | Python, Ruby, Node.js, Go, Java, .NET (official) |
| GoCardless | REST | Access token (OAuth2) | Yes (webhooks) | Python, Ruby, Node.js, Go, Java, .NET, PHP (official) |
| Checkout.com | REST | API key (secret + public) | Yes (webhooks) | Python, Node.js, Go, Java, .NET, PHP (official) |
| Wise Business | REST | API token (OAuth2) | Yes (webhooks) | No official SDKs (REST-based) |
Best developer experience: Stripe (most comprehensive SDK coverage, best documentation), Adyen (extensive SDKs, strong webhooks)
Most limited API: Authorize.Net (legacy XML API alongside REST; less modern developer experience)
Payment Methods
| Tool | Cards | ACH | SEPA | PayPal | Apple Pay | Google Pay | BNPL | Crypto |
|---|---|---|---|---|---|---|---|---|
| Kill Bill | Yes (via plugins) | Yes (via plugins) | Yes (via plugins) | Yes (via plugins) | No | No | No | No |
| Lago | Via gateway | Via gateway | Via gateway | Via gateway | Via gateway | Via gateway | No | No |
| Stripe | Yes | Yes | Yes | Yes | Yes | Yes | Yes (Klarna, Afterpay) | Yes (USDC) |
| Square | Yes | Yes | No | No | Yes | Yes | Yes (Afterpay) | No |
| PayPal / Braintree | Yes | Yes | Yes | Yes (native) | Yes | Yes | Yes (Pay Later) | Yes (limited) |
| Adyen | Yes | Yes | Yes | Yes | Yes | Yes | Yes (Klarna, Afterpay, Zip) | Yes |
| Authorize.Net | Yes | Yes | No | Yes | Yes | Yes | No | No |
| Mollie | Yes | No | Yes | Yes | Yes | Yes | Yes (Klarna, in3) | Yes (Bitcoin) |
| Paddle | Yes | No | No | Yes | Yes | Yes | No | No |
| Chargebee | Via gateway | Via gateway | Via gateway | Via gateway | Via gateway | Via gateway | No | No |
| Recurly | Via gateway | Via gateway | Via gateway | Via gateway | Via gateway | Via gateway | No | No |
| GoCardless | No | Yes | Yes | No | No | No | No | No |
| Checkout.com | Yes | Yes | Yes | Yes | Yes | Yes | Yes (Klarna, Tamara) | Yes |
| Wise Business | No | Yes | Yes | No | No | No | No | No |
Broadest payment methods: Stripe, Adyen, Checkout.com (cards + bank + wallets + BNPL + crypto)
Bank-only: GoCardless (ACH, SEPA, BACS specialist), Wise Business (international transfers)
Gateway-dependent: Kill Bill, Lago, Chargebee, Recurly (use Stripe, Braintree, or Adyen as underlying gateway)
Recurring Billing Features
| Tool | Subscriptions | Trials | Proration | Dunning | Metered Billing |
|---|---|---|---|---|---|
| Kill Bill | Yes | Yes | Yes | Yes (configurable) | Yes |
| Lago | Yes | Yes | Yes | Yes | Yes (primary focus) |
| Stripe | Yes (Stripe Billing) | Yes | Yes | Yes (Smart Retries) | Yes (usage records) |
| Square | Yes (basic) | No | No | Yes (basic) | No |
| PayPal / Braintree | Yes | Yes | Yes | Yes (retry logic) | No |
| Adyen | Yes (basic; partner with Chargebee/Recurly for advanced) | Yes | No | Yes | No |
| Authorize.Net | Yes (ARB) | No | No | Yes (basic retry) | No |
| Mollie | Yes | Yes | No | Yes (basic) | No |
| Paddle | Yes | Yes | Yes | Yes (recovery) | No |
| Chargebee | Yes (primary focus) | Yes | Yes | Yes (advanced) | Yes |
| Recurly | Yes (primary focus) | Yes | Yes | Yes (advanced ML) | Yes |
| GoCardless | Yes (direct debit mandates) | No | No | Yes (retry logic) | No |
| Checkout.com | No (use Chargebee/Recurly) | No | No | No | No |
| Wise Business | No | No | No | No | No |
Best subscription billing: Chargebee (most advanced subscription management), Recurly (ML-based dunning), Stripe Billing (integrated with payment processing)
Usage-based billing leaders: Lago (purpose- built for metered billing), Kill Bill (flexible plugin architecture), Stripe (usage records API)
No recurring billing: Checkout.com (payment gateway only; pair with Chargebee/Recurly), Wise Business (transfers only)
Multi-Currency & International
| Tool | Currencies | Local Acquiring | Settlement Currencies | International Payouts |
|---|---|---|---|---|
| Kill Bill | Unlimited (configurable) | Via gateway plugins | Via gateway | Via gateway |
| Lago | Unlimited (configurable) | Via gateway | Via gateway | Via gateway |
| Stripe | 135+ | Yes (30+ countries) | 40+ currencies | Yes (Stripe Connect) |
| Square | 5 (USD, CAD, GBP, AUD, JPY) | Yes (6 countries) | Local currency only | No |
| PayPal / Braintree | 100+ | Yes (45+ countries) | 20+ currencies | Yes (PayPal Mass Pay) |
| Adyen | 150+ | Yes (40+ countries) | 30+ currencies | Yes (Adyen for Platforms) |
| Authorize.Net | 10+ (USD-focused) | US, Canada, Europe, Australia | USD, CAD, GBP, EUR | No |
| Mollie | 25+ | Yes (European focus) | EUR, GBP, USD | No |
| Paddle | 30+ | Yes (MoR handles local) | USD, GBP, EUR | N/A (MoR model) |
| Chargebee | 100+ | Via gateway | Via gateway | Via gateway |
| Recurly | 140+ | Via gateway | Via gateway | Via gateway |
| GoCardless | 8 (ACH, SEPA, BACS currencies) | Yes (30+ countries) | Local currency | No |
| Checkout.com | 150+ | Yes (45+ countries) | 20+ currencies | Yes |
| Wise Business | 50+ (send), 10+ (receive) | No (transfer service) | Multi-currency accounts | Yes (primary focus) |
Best international coverage: Adyen (150+ currencies, 40+ local acquiring), Stripe (135+ currencies, 30+ countries), Checkout.com (150+ currencies, 45+ countries)
Most limited: Square (5 currencies, 6 countries), Authorize.Net (US-centric)
Transfer specialist: Wise Business (multi-currency accounts, international transfers at mid-market FX rates)
PCI DSS Compliance Model
| Tool | PCI Level 1 | Hosted Pages | Tokenization | Merchant SAQ Level |
|---|---|---|---|---|
| Kill Bill | No (self-managed) | Via gateway | Via gateway plugins | Depends on gateway + self-hosting |
| Lago | No (self-managed) | Via gateway | Via gateway | Depends on gateway |
| Stripe | Yes | Stripe Checkout | Yes (Payment Methods API) | SAQ-A (Checkout/Elements) |
| Square | Yes | Square Web Payments SDK | Yes (card nonce) | SAQ-A (Web Payments SDK) |
| PayPal / Braintree | Yes | PayPal Checkout, Braintree Drop-in | Yes (payment method nonce) | SAQ-A (Drop-in UI) |
| Adyen | Yes | Adyen Drop-in, Components | Yes (recurring tokens) | SAQ-A (Drop-in/Components) |
| Authorize.Net | Yes | Accept.js, Accept Hosted | Yes (customer profiles) | SAQ-A-EP (Accept.js) or SAQ-A (Accept Hosted) |
| Mollie | Yes | Mollie Checkout | Yes (mandates) | SAQ-A (Checkout) |
| Paddle | Yes (MoR handles) | Paddle Checkout | Yes (MoR vault) | None (Paddle is MoR) |
| Chargebee | Yes (via gateway) | Chargebee Hosted Pages | Yes (via gateway) | SAQ-A (Hosted Pages) |
| Recurly | Yes (via gateway) | Recurly.js | Yes (via gateway) | SAQ-A (Recurly.js) |
| GoCardless | N/A (no card data) | GoCardless mandate flow | N/A (bank mandates) | N/A (no card processing) |
| Checkout.com | Yes | Checkout.com Frames | Yes (tokens) | SAQ-A (Frames) |
| Wise Business | N/A (no card processing) | N/A | N/A | N/A |
Simplest PCI compliance: Paddle (MoR model; merchant has zero PCI obligations), GoCardless (no card data), Wise (no card processing)
SAQ-A achievable: Stripe, Square, Adyen, PayPal/Braintree, Mollie, Chargebee, Recurly, Checkout.com (all offer hosted payment pages or iframe-based elements)
Pricing
| Tool | Transaction Fees | Monthly/Annual Fees | Cross-Border Fee |
|---|---|---|---|
| Kill Bill | None (self-hosted) | Free (Apache-2.0) | N/A (via gateway) |
| Lago | None (self-hosted) | Free (AGPL-3.0); Premium from $500/mo | N/A (via gateway) |
| Stripe | 2.9% + $0.30 (US cards) | None (pay per transaction) | +1.5% cross-border |
| Square | 2.6% + $0.10 (in-person); 2.9% + $0.30 (online) | None (pay per transaction) | N/A (limited international) |
| PayPal / Braintree | 2.59% + $0.49 (PayPal); 2.59% + $0.49 (Braintree) | None (pay per transaction) | +1.5% cross-border |
| Adyen | Interchange++ (IC + scheme fee + $0.13) | None (minimum monthly fee may apply) | Varies by corridor |
| Authorize.Net | 2.9% + $0.30 | $25/mo gateway fee | N/A (US-focused) |
| Mollie | 1.8% + EUR 0.25 (EU cards) | None (pay per transaction) | +0.6% non-EU |
| Paddle | 5% + $0.50 (includes tax handling) | None (pay per transaction) | Included (MoR model) |
| Chargebee | None (gateway fees apply) | From $0 (Starter) to custom (Enterprise) | Via gateway |
| Recurly | None (gateway fees apply) | From $0 (Core) to custom (Enterprise) | Via gateway |
| GoCardless | 1% + $0.25 (ACH); variable (SEPA/BACS) | None (pay per transaction) | +0.3% FX fee |
| Checkout.com | Interchange++ or blended (custom) | None (custom pricing) | Varies by corridor |
| Wise Business | 0.41%–2.0% (transfer fees vary by corridor) | None (pay per transfer) | Included (mid-market rate) |
Lowest card fees: Adyen and Checkout.com (interchange++ pricing for volume merchants)
Lowest bank transfer fees: GoCardless (bank-to-bank specialist), Wise Business (international transfers at mid-market rates)
Most expensive: Paddle (5% + $0.50, but includes tax compliance and MoR services)
Free self-hosted: Kill Bill (Apache-2.0), Lago (AGPL-3.0 for community edition)
Deployment and Licensing
| Tool | License | Self-Hosted | Language | Database | Docker |
|---|---|---|---|---|---|
| Kill Bill | Apache-2.0 | Yes | Java | MySQL, PostgreSQL | Yes |
| Lago | AGPL-3.0 | Yes | Ruby, TypeScript | PostgreSQL, Redis | Yes |
| Stripe | Proprietary | No (SaaS) | – | – | – |
| Square | Proprietary | No (SaaS) | – | – | – |
| PayPal / Braintree | Proprietary | No (SaaS) | – | – | – |
| Adyen | Proprietary | No (SaaS) | – | – | – |
| Authorize.Net | Proprietary | No (SaaS) | – | – | – |
| Mollie | Proprietary | No (SaaS) | – | – | – |
| Paddle | Proprietary | No (SaaS) | – | – | – |
| Chargebee | Proprietary | No (SaaS) | – | – | – |
| Recurly | Proprietary | No (SaaS) | – | – | – |
| GoCardless | Proprietary | No (SaaS) | – | – | – |
| Checkout.com | Proprietary | No (SaaS) | – | – | – |
| Wise Business | Proprietary | No (SaaS) | – | – | – |
Self-hosted: Kill Bill (Apache-2.0), Lago (AGPL-3.0)
All commercial tools are SaaS-only – no self-hosted option. Payment processing requires PCI DSS Level 1 infrastructure, which is impractical for most organizations to build and maintain.
AGPL-3.0 Note
Lago uses AGPL-3.0, which requires sharing modifications with all network users. Organizations must evaluate whether AGPL obligations are acceptable. The same caution applies as noted in the Wiki & Knowledge Base, Workflow Automation, Digital Signatures / E-Sign, and Low-Code / No-Code Platforms evaluations.
Tools
14 tools.
Adyen
Adyen is an enterprise-focused payment platform that provides unified commerce across online, in-store, and mobile channels.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
Authorize.Net
Authorize.Net is one of the oldest and most widely deployed payment gateways in the United States, operating since 1996.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
Chargebee
Chargebee is a subscription management and billing platform that sits as an orchestration layer above payment gateways.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: OIDC
Checkout.com
Checkout.com is an enterprise payment platform providing card processing, alternative payment methods, and payout capabilities across 150+ currencies and 45+ countries.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
GoCardless
GoCardless is a bank-to-bank payment specialist that enables businesses to collect payments via ACH Direct Debit (US), SEPA Direct Debit (Europe), BACS Direct Debit (UK), BECS Direct Debit (Australia), PAD (Canada), and Autogiro (Sweden).
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
Kill Bill
Kill Bill is an open-source billing and payment platform built in Java with an extensible plugin architecture.
License: Apache-2.0 (OSS) · Kind: web · Deploy: native · SSO: none
Lago
Lago is an open-source usage-based billing platform designed for SaaS companies with metered or consumption-based pricing models.
License: AGPL-3.0-only (OSS) · Kind: web · Deploy: native · SSO: none
Mollie
Mollie is a European payment service provider based in the Netherlands, offering online payment processing with a focus on European payment methods.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
Paddle
Paddle is a proprietary payment platform that acts as a Merchant of Record for SaaS companies, handling global tax compliance, subscription billing, checkout, and PCI obligations on the seller’s behalf.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
PayPal / Braintree
PayPal is the world’s most recognized online payment brand, with over 400 million active accounts globally.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
Recurly
Recurly is a subscription billing platform specializing in subscription management, revenue optimization, and churn reduction.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
Square
Square is a commerce platform that provides payment processing for both in-person (point-of-sale) and online transactions.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
Stripe
Stripe is the de facto standard for developer-first payment processing. It provides a unified platform for accepting payments, managing subscriptions, handling payouts, preventing fraud, and issuing virtual and physical cards.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
Wise Business (TransferWise)
Wise Business (formerly TransferWise Business) is an international money transfer and multi-currency account platform.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
