Stax (formerly Fattmerchant) replaces percentage-based merchant processing with a flat monthly subscription, passing through interchange at cost.
Stax is a subscription-based merchant processor that charges a flat monthly fee plus interchange-only transaction costs — no percentage markup. For businesses processing more than ~$8K/month, this typically beats Stripe or Square on total cost. The platform includes invoicing, payment links, and a dashboard with reporting.
Aggregated from verified user reviews on G2, Capterra, Trustpilot, and GetApp. Refreshed quarterly.
"Switching to Stax cut our merchant fees by about 40%. The subscription model finally made our processing costs predictable."
"Dashboard is clean and reporting is solid. Hardware setup took a couple of days longer than promised but support was responsive."
"Best for established businesses. If you're under $8K/month in volume, the $99 base fee won't pencil out."
Start a free trial and see if Stax fits your workflow. No credit card required for most plans.
Once you process more than roughly $8,000/month, Stax's subscription + interchange-only model usually beats Stripe's flat 2.9% + $0.30.
Yes. Stax supports in-person, online, invoicing, ACH, and recurring payments from one dashboard.
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