Stax

Also called Stax Payments, Fattmerchant, subscription pricing

A subscription-pricing processor: pay a monthly membership, then pay interchange plus a few cents. Wins above roughly $10-11K a month.

What it is

Stax, formerly Fattmerchant, pioneered the subscription pricing model in US merchant services. Instead of a percentage markup, you pay a flat monthly membership fee and then pay interchange plus a small per-transaction amount with no percentage markup at all. Published tiers run $99/month for merchants under $150,000 a year, $139/month from $150,000 to $250,000, and $199+/month above $250,000, with interchange plus $0.08 card-present, plus $0.15 keyed, ACH at 1% capped at $10, and PCI at $10/month. The arithmetic is the entire product. Because there's no percentage markup, your cost above interchange stops growing as your volume grows — which means the model gets progressively better the more you process. Published analysis puts the breakeven against flat-rate pricing at roughly $10,000–$11,000 a month in volume. Below that, a flat rate is usually cheaper. Above it, subscription pricing pulls ahead and keeps pulling. Stax is a processor and a payment platform, not a restaurant POS. It's most naturally a fit for retail, professional services, eCommerce and B2B — businesses with meaningful volume and no need for coursing and floor plans.

Why it matters to your business

As a rule of thumb, if you process more than about $10,000–$11,000 a month, subscription pricing deserves an actual model, not a dismissal. The savings compound as you grow, because the provider's cut stops scaling with your volume. But model it against your real seasonal pattern, not an annual average. Twelve months of $199 is $2,388 whether you did $80,000 in February or $12,000 in August, and a seasonal business should price that fixed cost honestly rather than optimistically.

Where it gets contested

The subscription model's fair criticism is that the monthly fee is a fixed cost that doesn't care about your seasonality. In Southwest Florida, where many businesses do 70% of their revenue between November and April, a $199 monthly membership across a dead August is worse than it looks in an annualized model. The correct comparison is not annual average volume — it's month by month across a real season. The second issue is that subscription pricing shifts the negotiation from a rate to a tier, and tier boundaries are set by the provider. A merchant just over a threshold pays the higher membership regardless of how far over they are. Third, PCI at $10/month and other ancillary fees stack on top, so the "membership plus interchange" framing is slightly cleaner in marketing than on the statement. That's a mild complaint — Stax publishes these figures, which most competitors don't. The strong version of the case for Stax is simply that the model is honest about where a processor's margin comes from. A monthly fee you can see beats a basis point spread you can't. Merchants who dislike the model usually dislike paying visibly for something they were previously paying invisibly for.

How to check it yourself

Build a twelve-row spreadsheet: your actual card volume by month for the last year. For each month, compute (a) your current cost and (b) membership fee plus interchange plus $0.08 per transaction. Sum both columns. If subscription pricing wins across the full year including your slow months, it's real. If it only wins in season, it isn't.

Receipts

Claims above that are checkable, with where to check them. Published so you do not have to take anyone's word for it.

Stax pricing: $99/mo under $150K/yr, $139/mo $150–250K, $199+/mo above $250K, interchange + $0.08 card-present, + $0.15 keyed, ACH 1% capped $10, PCI $10/mo, with breakeven versus flat-rate around $10–11K/month volume
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