The short version: Helcim wins for most small businesses. Stax wins once you’re processing roughly $40,000+ per month in person or ~$18,000–$30,000+ per month online (depending on your average ticket). Below those lines, Stax’s $159/month subscription eats its own savings. Above them, Stax’s zero-markup model pulls ahead and keeps pulling.
If you want the one-sentence decision rule: under $40k/month, go Helcim. Over $40k/month, price out Stax. The rest of this guide is the math that proves it.
Last updated: September 2026. Pricing verified against Stax and Helcim’s published pages and current third-party reviews. See sources at the bottom.
Disclosure: Merchant Verdict is reader-supported. We may earn a commission if you sign up through links on this page — it doesn’t change our verdicts, and it never costs you extra. [AFFILIATE LINK: Stax] [AFFILIATE LINK: Helcim]
How we compared them
We don’t take processors’ marketing at face value. For this comparison we pulled the current published rate cards from both companies, cross-checked them against 2026 reviews from NerdWallet, Business.com, and Business News Daily, and ran the break-even math ourselves across in-person and online scenarios at multiple ticket sizes. Where the companies’ own claims conflicted (looking at you, Helcim’s Stax review page), we went with the published numbers. No hands-on accounts were opened; this is deep research, not a lab test — and we’ll tell you exactly where the numbers come from.
Stax vs Helcim: pricing at a glance
| Stax | Helcim | |
|---|---|---|
| Pricing model | Subscription + interchange (0% markup) | Interchange-plus |
| Monthly fee | $99/mo (Growth, up to $150k/yr volume); $159/mo Pro; $199/mo Ultimate | $0 |
| In-person rate | $0.08/transaction + interchange (0% markup) | Interchange + 0.40% + 8¢ |
| Online / keyed rate | $0.15/transaction + interchange (0% markup) | Interchange + 0.50% + 25¢ |
| Volume discounts | Higher tiers by annual volume (custom above $500k) | Automatic — markup drops to 0.15% + 6¢ at $1M+/mo |
| PCI compliance fee | $0 (included) | $0 |
| Contract | Month-to-month, no early termination fee | No contract, no cancellation fee |
| Chargeback fee | Not prominently disclosed — ask sales | $15 (only if you lose) |
| Recurring billing surcharge | Included in tiers | +0.40% per transaction |
Sources: Stax pricing via Business News Daily and Comparisun (2026 reviews); Helcim pricing via helcim.com/pricing and Business.com (2026).
The structural difference is everything: Stax charges you a flat monthly subscription ($159 on the Pro tier most growing businesses land in) and then takes $0 cut of each sale’s percentage. Helcim charges $0/month and takes a small percentage of each sale. That means there is a mathematically exact volume where one becomes cheaper than the other. Let’s find it.
The break-even math: in-person transactions
For in-person sales, both companies charge the same 8¢ per-transaction fee. Interchange (the wholesale cost set by Visa/Mastercard) is identical for both since it’s passed through at cost. So the only difference is:
- Stax: $159/month flat (Pro tier — the tier a business at this volume actually pays; see note below)
- Helcim: 0.40% of your monthly volume
Break-even: $159 ÷ 0.0040 = $39,750/month — call it $40k.
| Monthly in-person volume | Stax cost (above interchange) | Helcim cost (above interchange) | Winner |
|---|---|---|---|
| $10,000 | $159 + ~$11 txn fees = ~$170 | $40 + ~$11 = ~$51 | Helcim (saves ~$119/mo) |
| $25,000 | $159 + ~$27 = ~$186 | $100 + ~$27 = ~$127 | Helcim (saves ~$59/mo) |
| $40,000 | $159 + ~$43 = ~$202 | $160 + ~$43 = ~$203 | Tie |
| $50,000 | $159 + ~$53 = ~$212 | $200 + ~$53 = ~$253 | Stax (saves ~$41/mo) |
| $100,000 | $159 + ~$107 = ~$266 | $400 + ~$107 = ~$507 | Stax (saves ~$241/mo) |
Assumes ~$75 average ticket for transaction-count estimates. Interchange excluded from both sides since it’s identical.
The in-person rule: below ~$40k/month, Helcim. Above it, Stax — and the gap widens fast. At $100k/month, Stax saves you roughly $2,900/year over Helcim. (Note: Helcim’s own comparison page claims Stax only wins above $100k/month — their math assumes Stax’s top tiers. On the published Pro-tier numbers, the line is ~$40k.)
A note on tiers: Stax’s $99 Growth tier only covers up to $150,000/year in volume ($12,500/month) — and at that volume Helcim wins regardless. Any business near the break-even line is in the $159/month Pro tier, so Pro is the honest basis for the math and $40k/month is the practical line.
The break-even math: online transactions
Online, the math shifts because the per-transaction fees differ (Stax $0.15 vs Helcim $0.25) and Helcim’s percentage markup is higher (0.50%). Break-even depends on your average ticket size:
| Avg. online ticket | Approx. monthly volume where Stax wins |
|---|---|
| $25 | ~$17,500/month |
| $50 | ~$23,000/month |
| $100 | ~$26,500/month |
| $250 | ~$29,500/month |
Derived from: $159 = 0.005 × volume + $0.10 × transaction count. Smaller tickets favor Stax sooner because Helcim’s 25¢-vs-15¢ per-transaction gap bites harder.
The online rule: if you sell online and process more than roughly $25k/month, Stax is probably cheaper. Below that, Helcim.
Three real-world scenarios
Scenario 1: Coffee shop, $18k/month, $12 average ticket, all in-person. Helcim: 0.40% × $18,000 = $72 + ~$120 in per-txn fees = ~$192/mo above interchange. Stax: $159 + ~$120 = ~$279/mo. Winner: Helcim, by ~$87/month (~$1,044/year). Plus no monthly commitment hanging over a seasonal business.
Scenario 2: Home-services company, $45k/month, $400 average ticket, mix of in-person and invoiced. In-person portion ($30k): Stax $159 (Pro tier) + fees vs Helcim 0.40% × $30k = $120 + fees → Helcim ahead by ~$39/mo. Online/invoiced portion ($15k): Helcim 0.50% × $15k = $75 + ~$4 in extra per-txn fees vs Stax $159 → Helcim ahead by ~$80/mo. Winner: Helcim, narrowly — this business sits just under both break-even lines. Push past ~$40k/month in person or ~$25k/month online and Stax takes the lead. Also note Stax’s invoicing and recurring billing are stronger for this use case.
Scenario 3: Online boutique, $60k/month, $65 average ticket, all online. Stax: $159 + $0.15 × ~923 txns = ~$297/mo above interchange. Helcim: 0.50% × $60,000 = $300 + $0.25 × 923 = ~$531/mo. Winner: Stax, by ~$234/month — ~$2,800/year. This is the profile Stax was built for.
Beyond price: what else separates them
Software and POS. Helcim includes a free POS app, online store builder, invoicing, and payment pages at no extra charge. Stax offers dashboards, invoicing, and recurring billing, but does not offer its own POS software — it integrates with third-party POS systems (90%+ compatibility claimed) and can reprogram existing terminals for free. If you want one vendor for everything including the register software, Helcim. If you already have hardware you like, Stax.
Hardware. Helcim sells its own card reader ($199) and smart terminal ($349). Stax is equipment-agnostic — buy from them (Clover, Dejavoo, Verifone, SwipeSimple near cost) or bring your own. Advantage: Stax, for flexibility.
Funding speed. Stax offers next-day and accelerated (same/next-day) funding; some add-ons cost extra. Helcim deposits next business day where supported, with no same-day option. Slight edge: Stax.
Support. Both offer human support (Helcim 6 days/week; Stax via its service team). Third-party reviews note occasional Stax account holds for high-volume merchants — worth knowing, since Stax runs on Worldpay’s backend and some hold decisions sit outside Stax’s direct control (Comparisun, 2026).
Transparency gotchas. Stax’s Growth/Pro tier pricing requires a sales call for exact quotes, and its chargeback fee isn’t prominently disclosed — ask before signing. Helcim publishes everything, including the $15 lost-chargeback fee and the 0.40% recurring-billing add-on. Helcim wins on transparency, comfortably.
Pros and cons
Stax – ✅ 0% markup on interchange — unbeatable at high volume – ✅ No PCI compliance fee, no long-term contract, no early termination fee – ✅ Equipment-agnostic; free terminal reprogramming – ✅ Strong invoicing, recurring billing, and analytics platform – ❌ $159/month is dead money below ~$40k/mo in-person volume – ❌ Tier pricing details require a sales call; chargeback fee not disclosed upfront – ❌ No native POS software – ❌ Documented account holds for some high-volume merchants
Helcim – ✅ $0 monthly fee — nothing to lose by trying it – ✅ Fully published, transparent pricing; automatic volume discounts – ✅ Free POS software, invoicing, and online store tools included – ✅ Excellent for low-to-mid volume and debit-heavy businesses – ❌ Percentage markup means costs scale with you — punishing at high volume – ❌ No same-day funding option – ❌ 0.40% add-on for recurring billing; $15 lost-chargeback fee
The verdict
Choose Helcim if: you process under ~$40k/month in person (or ~$25k/month online), you’re just starting out, you want $0 in fixed costs, or you need free POS software out of the box. It’s the best low-risk processor in the industry — NerdWallet’s 5.0/5 rating is deserved. [AFFILIATE LINK: Helcim]
Choose Stax if: you process over ~$40k/month in person (or ~$25k+/month online) and want the lowest possible effective rate at scale. The subscription stings at first, then it becomes the cheapest money in payments. Just get the full fee schedule in writing before you sign. [AFFILIATE LINK: Stax]
Choose neither if: you process under ~$5k/month and want dead-simple flat-rate pricing with no learning curve — that’s Square’s territory (see our Square vs Helcim breakdown).
Frequently asked questions
Is Stax legit? Yes. Stax (formerly Fattmerchant, rebranded 2021) is a registered ISO/MSP operating since 2014, headquartered in Orlando, FL. It also owns Payment Depot and CardX. It’s a real merchant services provider, not a startup gamble — though it processes through Worldpay’s backend, which matters for the account-hold reports noted above.
Why is Stax $159/month when Helcim is free? Different business models. Stax bets that a flat subscription plus zero percentage markup saves high-volume merchants more than the subscription costs. Helcim bets that a small percentage with no fixed fee is friendlier for everyone else. Both bets are correct — for their respective audiences.
Can I switch from Helcim to Stax later? Yes, and it’s a common growth path: start on Helcim’s $0/month plan, and when your volume crosses ~$40k/month in person (or ~$25k/month online), price out Stax. Neither charges an early termination fee, so there’s no penalty for graduating.
Does Stax really have no contract? Correct — month-to-month with no early termination fee. It does require 30 days’ written notice to cancel, so don’t expect to flip a switch overnight.
Which is better for invoicing? Both handle invoicing well. Stax’s invoicing and recurring billing are more fully featured (scheduled payments, card updater), especially on Pro/Ultimate tiers. Helcim’s invoicing is free and perfectly good for straightforward use.
Methodology & sources
Pricing figures verified September 2026 from: Stax’s published pricing and third-party reviews (Business News Daily, Comparisun, Website Planet); Helcim’s published pricing page (helcim.com/pricing) and Business.com’s 2026 review. Break-even calculations are our own, derived from published rate cards; per-transaction counts estimated from stated average tickets. Interchange costs are excluded from head-to-head comparisons because both processors pass them through at cost. Scenario outcomes are illustrative — your card mix (rewards vs. debit) moves the real numbers.
Sources: – Business News Daily — Stax Review 2026: https://businessnewsdaily.com/16593-stax-by-fattmerchant.html – Comparisun — Stax Payments Review (May 2026): https://www.comparisun.com/credit-card-processing/reviews/stax-reviews/ – Website Planet — Stax review: https://www.websiteplanet.com/credit-card-processing/stax/ – Helcim official pricing: https://www.helcim.com/pricing/ – Business.com — Helcim review 2026: https://www.business.com/reviews/helcim-credit-card-processing/ – NerdWallet — Helcim Review 2026 (comparison data): https://www.nerdwallet.com/business/software/reviews/helcim – paymentsandrisk.com — Processor Comparison for SMBs (24-scenario analysis): https://paymentsandrisk.com/docs/payments/processor-comparison/