Who this comparison is for
Solo operators, small e-commerce, single-location retail crossing the $10K monthly bar but not yet at the threshold where interchange-plus saves money.
Recommended processors for $10K–$25K monthly
The 4 processors below are the ones whose published rates, contract terms, and operator-side reputation hold up at this volume. Effective rates assume a normalized U.S. SMB card mix (60% credit, 40% debit, 30% rewards). See the methodology page for full assumptions.
1. Square
2.65–2.95% blendedFlat-rateBest for
Brick-and-mortar retail, restaurants, salons — anywhere card-present transactions dominate.
Watch out for
Account holds and 30-day stabilization windows on new accounts. Online rate (2.9% + $0.30) is fine; in-person is the value play.
2. Stripe
2.88–2.97% onlineFlat-rateBest for
Online-only operators, SaaS, marketplaces, subscription billing under $25K monthly.
Watch out for
Rolling reserves on subscription / high-risk verticals. Lacks integrated POS.
3. Helcim
2.41–2.51% (interchange + 0.40–0.50%)Interchange-plusBest for
Mixed channel businesses on the high end of this tier ($20K+ monthly) where IC+ already beats flat-rate.
Watch out for
No same-day deposit. Onboarding asks for balance sheet + P&L, which slows time-to-live.
4. PayPal
2.97–3.07% online + $0.49 fixedFlat-rateBest for
Adding PayPal as a secondary checkout option on an existing site to capture buyers who prefer PayPal-balance payment. Not as a primary.
Watch out for
The $0.49 fixed fee dominates effective rate on tickets under $30 — micropayment-heavy businesses overpay.
Pricing-model breakdown at $10K–$25K monthly
At $10K–$25K monthly monthly volume, three pricing models compete: flat-rate or auto-discount interchange-plus on the entry end, subscription interchange-plus in the middle, and custom IC++ contracts at the top. Here is the math on each.
Tier 1
Entry flat-rate
Square / Stripe / PayPal
$0 monthly fee · 2.6–2.9% + $0.10–$0.30 per transaction
Best for
$10K–$20K monthly. Predictable simple pricing.
What’s included
- ·No monthly fee
- ·No PCI fee on basic plan
- ·Free reader (Square)
- ·Standard fraud screening
- ·Next-business-day funding
Tier 2
Mid-tier interchange-plus
Helcim
$0 monthly fee · Interchange + 0.40–0.50% + $0.08–$0.25 per transaction
Best for
$20K–$25K+ monthly with stable card mix. Begins to beat flat-rate on math.
What’s included
- ·No monthly fee or contract
- ·Auto-applied volume discounts above $25K
- ·Free virtual terminal
- ·Real interchange pass-through
- ·Next-business-day deposit
Tier 3
Subscription IC-plus
Stax / Payment Depot
$79–$199 monthly + Interchange + ~0%–0.20% markup
Best for
Not yet — wait until $30K+ monthly to justify subscription cost.
What’s included
- ·Lowest per-transaction markup
- ·Interchange-plus pricing
- ·Premium support
- ·Often free or discounted hardware
- ·Not cost-effective at this tier
The actual math at $10K–$25K monthly
At $15,000 monthly volume on a typical SMB card mix (60% credit, 40% debit, 30% rewards, $74 average ticket), the math runs: Square at 2.75% effective ≈ $412/month. Helcim at 2.51% effective ≈ $377/month. Stax at $99/mo subscription + 2.21% effective ≈ $431/month. Helcim wins by ~$35/month at this volume — but only if the merchant is at the upper end of the tier. Below $15K monthly, Square's simplicity wins on total cost including time spent reconciling.
Sources
- myPayAdvisor 2026 Payment Processor Effective Rate Database — open dataset, CC-BY-4.0. View
- myPayAdvisor Research Methodology — card-mix assumption, sample selection, calculation method. View
- Federal Reserve Payments Study series — U.S. SMB card-mix distribution. federalreserve.gov
- Processor public pricing pages (captured 2026-04-30): Stripe, Square, Helcim, PayPal, Stax, Payment Depot, Adyen, Worldpay, Clover, Authorize.net, Braintree, Shopify Payments.