Finix vs. Stax: How they compare

Stax's subscription model can work well for established SMBs. For businesses that need card data portability, platform payments, or a direct processor relationship, Finix offers greater ownership and flexibility.

Finix and Stax pricing compared

Quick recap of Direct Merchant Pricing Comparison

Stax’s pricing model differs from most processors by charging a flat per-transaction fee above interchange rather than a percentage markup. This can create savings for businesses with higher average transaction values and consistent volume. Finix uses a traditional interchange-plus model with a percentage-based markup, which can be more predictable for businesses with lower average ticket sizes or lower overall processing volume.

Platform and marketplace features compared

Pricing as of June 2026. Stax subscription tiers: up to $150K/yr: $99/mo; $150K–$250K/yr: $139/mo; $250K+/yr: $199+/mo. Applies to U.S.-based businesses. Stax Connect pricing is custom and not publicly listed — verify with Stax directly before publication.

What growing businesses should know

Finix

• Certified direct processor connecting to Visa, Mastercard, Discover, and Amex. Each merchant receives a dedicated merchant account.
• Full card data portability. Merchants own their tokenized card data and can migrate it without requiring customers to re-enter payment details
• Interchange-plus pricing with transparent per-transaction markup; no subscription floor for low-volume merchants
• Accepts payments online, in-person, and across channels from a single platform
• Platform and marketplace payments built into the core product. No separate products requiring a separate contract
• Dedicated account manager included for all merchants from day one

Stax

• Subscription-based pricing with 0% percentage markup on interchange. Merchants pay actual interchange cost plus flat cents per transaction ($0.08 in-person, $0.15 online), making it cost-effective for high-volume or high-ticket businesses
• Over 30,000 businesses trust Stax, processing more than $30 billion in payments
• Stax Connect serves SaaS and ISV platforms with embedded payments, white-labeling, and PayFac-as-a-Service — managed by Stax's full-service partnership team
• CardX by Stax provides compliant credit card surcharging automation, reducing or eliminating net processing costs for eligible businesses
• Next-day funding standard; instant and same-day options available as add-ons
• ACH processing, recurring billing (Stax Bill), and invoicing included in the platform

Integration and customization options

Finix

• RESTful API with webhooks and real-time event streams covering card payments and bank transfers
• No-code onboarding tools alongside full API access. Non-technical teams can get started without dedicated dev resources
• Tokenization and hosted fields to reduce PCI scope, with full card data portability on migration
• Dedicated sandbox environment for integration testing
• White-labeled checkout pages, payment links, and virtual terminal included, no extra development required

Stax

• RESTful API supports custom integrations with CRM, accounting, and business software (QuickBooks, HubSpot, Zapier, WooCommerce, Google Workspace)
• Android and iOS SDKs for mobile payment acceptance
• Stax Connect single API integration for ISVs — pre-built enrollment, automated settlements, and risk management; Stax claims a 30-day launch timeline
• iFrame support and webhook integration for embedded checkout flows
• Stax Bill API supports recurring billing, subscription lifecycle management, and dunning (failed payment recovery)

Frequently asked questions

What is the main difference between Finix and Stax pricing?
Both Finix and Stax use interchange-based pricing and merchants pay the actual interchange cost rather than a flat blended rate. The structural difference is how the processor's fee is applied. Stax charges a flat cents-per-transaction fee above interchange ($0.08 in-person, $0.15 online) with no percentage markup, plus a monthly subscription starting at $99. Finix uses a traditional interchange-plus model with a small percentage markup per transaction and a subscription from $99. For merchants with high average ticket sizes, Stax's flat cents model can produce lower per-transaction costs. For merchants with lower average tickets or lower overall volumes who want to avoid a monthly subscription floor, Finix's model may be more predictable.

Is Stax's "interchange plus zero" model better than interchange-plus?
It depends on your transaction profile. Stax charges interchange at cost plus flat cents per transaction with no percentage markup on top. On a $500 transaction, Stax's $0.08 fee is meaningfully less than a 0.15% markup ($0.75). On a $10 transaction, the difference is negligible. The subscription cost ($99–$199+/month) means low-volume merchants subsidize the pricing model regardless of transaction count. Merchants with consistent volumes and high average tickets typically benefit most from Stax's structure. Finix's interchange-plus model works well across a broader range of volume levels without a subscription requirement at entry.

Does Stax offer platform or marketplace payments?
Yes — through Stax Connect, a separate embedded payments product for SaaS companies and ISVs. Stax Connect offers white-labeling, a single API integration, sub-merchant onboarding, and a full-service partnership team that manages compliance, enrollment, and tier-1 merchant support. The Stax Connect Plus model means ISVs can offload much of the operational work to Stax. The key difference from Finix is the underlying processor relationship: Stax Connect operates on a PayFac or reseller model where Stax retains the direct connection to the card networks. Finix is a certified direct processor, giving platform partners a more direct relationship and full card data portability.

Can I move my card data away from Stax if I switch processors?
This is an important question to ask before signing with any processor. Finix provides full card data portability and tokenized card data can be migrated to another processor without requiring customers to re-enter their payment details. Stax's approach to card data portability on migration should be confirmed directly with Stax before signing, as it depends on the gateway and tokenization configuration in use. This matters especially for businesses with large numbers of stored customer payment methods or subscription billing.

Which businesses are best suited to Stax vs. Finix?
Stax is a strong fit for established SMBs processing $5,000 or more per month with consistent volume and higher average ticket sizes and the subscription model pays off quickly in those conditions. Stax Connect is a compelling option for SaaS companies and ISVs that want to embed payments quickly and prefer a managed model where Stax handles operational complexity. Finix is a better fit for businesses that need direct processor control, full card data ownership, platform and marketplace payment capability built into the core product, or flexibility across a wider range of volume levels without a subscription floor.

Can I migrate from Stax to Finix?
Yes. Finix supports full card data portability and tokenized card data can be migrated without requiring customers to re-enter payment details. The migration process depends partly on how your card data is currently stored in Stax's gateway; Finix's team will work through the specifics with you.