Stax Fees Explained: Complete 2026 Guide & Pricing Breakdown
Discover how Stax’s subscription-based payment processing works, what you’ll actually pay, and whether the membership model saves you money.
Stax charges a monthly membership fee of $99-$199 instead of traditional percentage-based processing fees. You pay actual interchange rates (typically 1.5-2.5%) plus just 8¢ per transaction—with zero markup on the percentage. For businesses processing $10,000+/month, this model typically saves 30-50% compared to flat-rate processors like Stripe or Square.
📋 Table of Contents
What Is Stax Payment Processing?
Stax (formerly Fattmerchant) is a subscription-based payment processor that flips the traditional pricing model on its head. Instead of charging 2.9% + 30¢ per transaction like Stripe or Square, Stax charges you a flat monthly membership fee and passes through interchange rates at cost.
How Stax’s Membership Model Works
Think of Stax like a Costco membership for payment processing. You pay an upfront monthly fee to access wholesale interchange rates. Here’s the difference:
Traditional Processors (Stripe, Square)
Pay per transaction
On a $100 sale, you pay $3.20
Stax Better Deal
Monthly membership
On a $100 sale, you pay $1.88
Interchange is the actual fee charged by Visa, Mastercard, and card-issuing banks (typically 1.5-2.5%). Traditional processors mark this up to 2.9% and pocket the difference. Stax passes through the real interchange rate with zero markup—you just pay 8¢ per transaction plus the monthly fee.
Stax Pricing & Fee Breakdown (2026)
Stax offers two main membership plans with different features and pricing tiers.
Stax Membership Plans
| Plan | Monthly Fee | Per-Transaction Fee | Features |
|---|---|---|---|
| Growth | $99/month | Interchange + 8¢ | Online payments, invoicing, reporting |
| Premium | $199/month | Interchange + 8¢ | Growth + in-person processing, advanced analytics |
| Ultimate | Custom pricing | Interchange + negotiable | Enterprise features, dedicated support |
Additional Stax Fees
| Fee Type | Cost |
|---|---|
| Setup/onboarding fee | $0 (no setup fee) |
| Chargeback fee | $25 per chargeback |
| ACH/eCheck | $1 per transaction |
| International cards | Interchange + 1% |
| PCI compliance fee | $0 (included) |
| Monthly minimum | None |
| Early termination fee | Varies by contract |
Stax typically requires a multi-year contract (often 3 years) with early termination fees. Make sure you understand the contract terms before signing. Some merchants report ETFs of $500+ if you cancel early.
How Much Does Stax Actually Cost? (Real Examples)
Let’s calculate what Stax would cost for different business types and compare it to traditional flat-rate pricing.
Example 1: Small E-commerce Store
Monthly sales: $10,000 • Average transaction: $50 • Transactions: 200/month
vs. Stripe (2.9% + 30¢): $350 • You save: $55/month ($660/year)
Example 2: Mid-Size SaaS Business
Monthly recurring revenue: $50,000 • Average subscription: $99/month • Transactions: 505/month
vs. Stripe (2.9% + 30¢): $1,602 • You save: $562/month ($6,744/year)
Example 3: High-Volume Retail Store
Monthly sales: $100,000 • Average ticket: $75 • Transactions: 1,333/month
vs. Stripe (2.9% + 30¢): $3,300 • You save: $1,294/month ($15,528/year)
Stax typically becomes cost-effective when you process $5,000-$7,000+/month. Below that threshold, the $99 monthly fee makes flat-rate processors more economical. Above $10,000/month, Stax’s savings become substantial.
Stax vs. Stripe, Square & PayPal
How does Stax stack up against the competition? Here’s a detailed comparison at different processing volumes.
Cost Comparison at $25,000/Month
| Processor | Monthly Cost | Annual Cost | vs. Stax |
|---|---|---|---|
| Stax (Growth) | $549 | $6,588 | — |
| Stripe (2.9% + 30¢) | $825 | $9,900 | $276/mo more |
| Square (2.9% + 30¢) | $825 | $9,900 | $276/mo more |
| PayPal (3.49% + 49¢) | $1,020 | $12,240 | $471/mo more |
| Helcim (Interchange + 0.3% + 8¢) | $555 | $6,660 | $6/mo more |
Feature Comparison
| Feature | Stax | Stripe | Square |
|---|---|---|---|
| Monthly fee | $99-$199 | $0 | $0 |
| Online payments | ✅ | ✅ | ✅ |
| In-person processing | ✅ (Premium+) | ✅ | ✅ |
| Invoicing | ✅ Included | ✅ (+0.4%) | ✅ Included |
| Virtual terminal | ✅ Included | ✅ | ✅ |
| Free hardware | ❌ Purchase required | ❌ | ✅ Free reader |
| Contract required | ✅ Typically 3 years | ❌ No contract | ❌ No contract |
| API for developers | ✅ Limited | ✅ Excellent | ✅ Good |
Who Should Use Stax?
Stax isn’t for everyone. Here’s who benefits most from their membership model:
Best For:
- ✅ Established businesses processing $10,000+/month consistently
- ✅ High-volume merchants ($50,000+/month) looking to maximize savings
- ✅ Businesses with predictable revenue who can commit to a contract
- ✅ B2B companies with larger average transaction sizes ($100+)
- ✅ Service businesses (contractors, agencies, consultants)
- ✅ Merchants who want transparent, wholesale pricing
Not Ideal For:
- ❌ New businesses or startups processing less than $5,000/month
- ❌ Seasonal businesses with inconsistent monthly volume
- ❌ Businesses needing flexibility (no contracts)
- ❌ Merchants selling very low-ticket items (under $10)
- ❌ Developers needing robust API integrations (Stripe is better)
- ❌ Businesses that can’t commit to a 3-year contract
To break even with Stax’s $99/month fee at 2.9% savings (vs. Stripe), you need to process approximately $5,500/month. Below this, Stripe’s zero monthly fee makes it cheaper despite higher per-transaction costs. For detailed strategies on reducing costs, see our guide on how to lower credit card processing fees.
Stax Pros & Cons
✅ Pros
- Significant savings for high-volume businesses ($500-$1,500+/month)
- True interchange-plus pricing with zero markup on percentages
- Transparent pricing—you see exactly what you’re paying
- All-in-one platform (payments, invoicing, reporting)
- PCI compliance included (saves $100+/year)
- No monthly minimums or volume requirements
- Excellent customer support (dedicated account managers)
❌ Cons
- Requires 3-year contract with early termination fees
- Not cost-effective for businesses under $5,000/month
- Higher chargeback fees ($25 vs. Stripe’s $15)
- Limited API compared to Stripe or Braintree
- Hardware must be purchased (not free like Square)
- Setup can be complex compared to plug-and-play options
- International payment support is limited
Hidden Costs & Gotchas to Watch For
1. The Contract Commitment
Stax’s biggest gotcha is the multi-year contract. Most merchants are locked into a 3-year agreement with early termination fees ranging from $295 to $995+ depending on when you cancel.
A merchant who signed up for Stax but decided to switch after 8 months was charged a $695 early termination fee plus had to pay the remaining monthly fees through the end of the contract year.
2. Hardware Costs
Unlike Square (which provides free card readers), Stax requires you to purchase hardware:
- Card reader: $50-$150
- Countertop terminal: $300-$600
- POS system integration: Varies
3. Higher Chargeback Fees
Stax charges $25 per chargeback compared to Stripe’s $15. If you’re in a high-chargeback industry (digital goods, subscription services), this adds up.
4. ACH Fees Can Be Expensive
While Stax charges just $1 per ACH transaction, this is actually more expensive than competitors for smaller ACH payments:
| Processor | ACH Fee | $500 ACH Cost | $5,000 ACH Cost |
|---|---|---|---|
| Stax | $1 flat | $1.00 | $1.00 |
| Stripe | 0.8% (max $5) | $4.00 | $5.00 |
| Square | 1% (min $1) | $5.00 | $50.00 |
5. International Transaction Fees
Stax adds 1% for international cards on top of interchange. Combined with typical international interchange of 2.5-3%, you’re paying 3.5-4% total—not much better than Stripe’s flat 4.4%.
Better Alternatives to Stax
Depending on your business model, these alternatives might be better fits:
1. Helcim – Best for Transparent Pricing
Helcim offers interchange-plus pricing (interchange + 0.3% + 8¢) with no monthly fee and no contracts. For businesses processing $20,000+/month, Helcim often beats Stax while offering complete flexibility.
2. Payment Depot – Best for Very High Volume
Similar membership model to Stax but with tiered pricing starting at $79/month. Better for businesses processing $100,000+/month with more flexible contract terms.
3. Stripe – Best for Flexibility & Small Businesses
No monthly fees, no contracts, and superior API. Better for businesses under $10,000/month or those needing maximum flexibility. Learn more in our complete Stripe fees guide.
4. Dual Pricing Solutions – Pay $0 in Fees
Instead of paying subscription fees or percentage fees, dual pricing lets you pass processing costs to customers who choose to pay by card. You keep 100% of the sale price.
With dual pricing, you pay $0 in processing fees—no monthly membership, no percentage, nothing. Customers simply choose between a card price and a cash/ACH price. Most businesses save more with dual pricing than with Stax’s membership model. Learn more about saving on credit card processing fees.
Frequently Asked Questions
Want to Pay $0 in Processing Fees?
Instead of paying monthly membership fees or percentage fees, dual pricing lets you eliminate processing costs entirely. We’ll show you exactly how it works for your business.
Get Your Free Analysis →
Team Merchant Insiders is the editorial and research team behind Merchant Insiders, an independent U.S.-focused publication covering credit card processing, payment pricing, and fee optimization for small and mid-size businesses.
Our team combines hands-on experience in merchant services with deep research into processing fees, pricing models, compliance rules, and processor contracts.