Last update at May 26, 2026
Stax Payments (formerly Fattmerchant) is a subscription-based merchant services platform that eliminates percentage markups on interchange, replacing them with a flat monthly fee and small per-transaction charges. Founded in 2014, rebranded to Stax in 2021, it now also owns Payment Depot and CardX by Stax.
| Feature | Details |
|---|---|
| Full Name | Stax (formerly Fattmerchant; rebranded 2021) |
| Best For | Established US businesses processing $8,000+/month |
| Pricing Model | Subscription + interchange + flat per-transaction (0% percentage markup) |
| Starting Price | $99/month + $0.08/transaction (swiped) + interchange |
| Keyed-In Rate | $99/month + $0.15/transaction + interchange |
| Free Trial | First month free (limited time) |
| PCI Fee | $0 (included in subscription) |
| Contract | Month-to-month; cancel anytime |
| Hardware | Equipment-agnostic; reprogram existing terminals free |
| Parent Company | Stax (also owns Payment Depot and CardX by Stax) |
| Integrations | QuickBooks, Google Business, Facebook, 90%+ POS systems |
Omni Integrated Payments: unified dashboard for all payment channels (in-person, online, invoiced). Real-time analytics. Customer data management. Invoicing and recurring billing. Developer API for custom integrations. Equipment-agnostic: reprogram existing terminals free; works with 90%+ of third-party POS systems.
Integrations: QuickBooks (auto-sync payroll journal entries), Google Business, Facebook, 90%+ third-party POS. No PCI compliance fee. Hardware available near cost; Dejavoo, Verifone, Clover, SwipeSimple.
| Pros | Cons |
|---|---|
| 0% markup on interchange | $99/month makes it poor value under $8,000/month processing |
| No PCI compliance fee | Account holds documented for some high-volume merchants without warning |
| Equipment-agnostic; reprogram existing terminals free | Growth/Pro pricing requires a sales call |
| Month-to-month; cancel anytime | Chargeback fee not prominently disclosed |
| First month free | Worldpay backend — some hold decisions outside Stax's direct control |
| Omni platform consolidates all payment channels | Not ideal for seasonal or low-volume businesses |
| Plan | Monthly | Swiped/Tap | Keyed-In | Interchange |
|---|---|---|---|---|
| Standard | $99/month | $0.08/transaction | $0.15/transaction | Pass-through (0% markup) |
| Growth / Pro | Custom quote | Custom | Custom | Pass-through (0% markup) |
Real-cost example: $20,000/month in card sales: $99/month subscription + approx. $40 transaction fees + approx. $340-$400 interchange (1.7-2.0%) = $479-$539/month. vs traditional 2.7% flat-rate = $540/month. Savings grow with volume.
BEST FOR $8,000+/MONTH: At lower volumes, the $99 monthly subscription erodes interchange savings. The break-even vs flat-rate processors is approximately $8,000-$10,000/month in card processing.
| Platform | Rating | Notes |
|---|---|---|
| Capterra | 4.4/5 | Cost savings, platform usability, customer service |
| Software Advice | Positive | Subscription pricing praised; 'saves my business money' |
| SelectHub | #5 payment software | Strong on scalability and user-centric design |
ACCOUNT HOLD WARNING: Multiple Stax Payments reviews document accounts frozen without advance warning, including high-volume merchants ($1M+/month). Worldpay (backend processor) may be involved in hold decisions. Maintain a backup payment processing option for operational continuity.
Stax is a sophisticated, subscription-based credit card processor and payment gateway that can be a big win for the right profile of merchant—and a mismatch for the wrong one.
Best for: Established US businesses processing $8,000+/month wanting 0% markup, unified multi-channel dashboard, equipment flexibility, and month-to-month terms.