A payment processor for a small business is the layer that accepts a customer’s card or bank transfer and moves the funds into your business bank account. Most processors charge a flat percentage plus a small fixed fee per transaction. The fee looks tiny on every receipt.
At scale, the fee becomes the largest discretionary line item on your monthly books after payroll. Picking the wrong one for your transaction mix can cost several thousand dollars a year for no added value.
The right processor for a small business matches three things: the channel you actually sell through (online, in person, or both), your average ticket size, and the fee tiers that quietly hit at the margins. The wrong processor charges for features you never use or holds funds longer than competitors do.
Stripe wins for online-only businesses that need the lowest fixed per-transaction fee and an API that scales with the rest of their stack. Square wins for in-person retail and service businesses that want free point-of-sale software with the lowest card-present rate. PayPal wins for consumer-facing e-commerce where customer trust at checkout raises conversion. For tight-fee ACH workflows, Helio and Stripe’s ACH routing beat every card option on large invoices.
Key facts: Stripe charges 2.9 percent plus 30 cents for online card payments and 2.7 percent plus 5 cents in person. Square charges 3.3 percent plus 30 cents online and 2.6 percent plus 15 cents in person. PayPal charges 3.49 percent plus 49 cents for standard online card payments. ACH transfers through Stripe cap at 5 dollars per transaction.
Stripe is the developer-friendly online payments layer built for businesses that take card payments through a website, an app, or an invoice. Its online rate of 2.9 percent plus 30 cents matches the field, but the lower 30 cent fixed fee is where it edges out PayPal’s 49 cent charge. On one thousand monthly online transactions, that difference alone is roughly 190 dollars.
Square is the integrated point-of-sale and payments layer built for retail, food service, and in-person service businesses. The free POS software handles inventory, employee management, sales reporting, and customer records. Its in-person rate of 2.6 percent plus 15 cents is the lowest flat card-present rate among major processors.
PayPal is the consumer-trusted payments layer where customers recognize the button at checkout. Its standard online rate of 3.49 percent plus 49 cents is the highest among the big three, but the conversion lift from a familiar PayPal button is real for newer brands. Pair it with Stripe to offer both rather than picking one.
Helio and a small set of newer fintechs focus on ACH-first and invoice-heavy workflows. ACH at 0.8 percent capped at 5 dollars through Stripe or comparable flat-fee ACH at Helio turns a 5,000 dollar invoice into roughly 5 dollars in fees instead of 145 dollars through a card processor. That math matters when invoices are large and infrequent.
| Processor | Online Card Rate | In-Person Card Rate | ACH / Bank Transfer | Chargeback Fee | Monthly Fee |
|---|---|---|---|---|---|
| Stripe | 2.9% + $0.30 | 2.7% + $0.05 | 0.8% (max $5) | $15 | $0 |
| Square | 3.3% + $0.30 | 2.6% + $0.15 | 1% ($1 min, $5 max via invoice) | Included | $0 (Free) |
| PayPal | 3.49% + $0.49 | 2.29% + $0.09 (Zettle) | Not standard | $20 ($8 with Seller Protection) | $0 |
| Helio | ACH-focused | Not standard | Flat 1% | $0 | $0 |
| Shopify Payments | 2.9% + $0.30 (Basic) | 2.7% + $0.00 | Not standard | Varies | From $39/mo |
Quick stat: A business processing 10,000 dollars monthly in online card payments pays roughly 290 dollars in Stripe fees, 330 dollars in Square fees, and 349 dollars in PayPal fees before any chargeback or international surcharges. That spread widens as volume scales.
The honest traps: what processors do not put on the headline rate
Chargeback fees hide in dispute volume. Stripe charges 15 dollars per chargeback, refunded only if you win the dispute. Square folds the cost into its standard rate with no separate fee. PayPal charges 20 dollars per chargeback, or 8 dollars with Seller Protection if you meet eligibility rules. If your business sees occasional disputes, Square’s all-in rate is a quiet win.
International cards carry a 1.5 percent surcharge on every platform. Stripe, Square, and PayPal all add roughly 1.5 percent for international card transactions. Add another 1 percent if Stripe converts currency on your behalf. If 30 percent of your sales are international, your effective rate is meaningfully higher than the headline.
Manual entry and card-on-file rates are higher than the headline. Square charges 3.5 percent plus 15 cents for keyed-in or stored-card transactions. Stripe’s online rate already covers most card-on-file flows, but phone orders at Square will run at the manual rate. Reconciling chargebacks against the wrong tier is a common surprise at month-end.
ACH caps protect you on large invoices, but ACH fees vary widely. Stripe caps ACH at 5 dollars per transaction; Square charges 1 percent with a 1 dollar minimum and 5 dollar cap on ACH via invoice. Helio charges a flat 1 percent. On a 4,000 dollar invoice, Stripe ACH costs 5 dollars; a card processor would charge roughly 116 dollars for the same payment.
Payment holds and rolling reserves hit cash flow, not just fees. Stripe and Square reserve a percentage of funds for new merchants and high-risk categories. PayPal holds funds for new sellers more aggressively than competitors. None of this shows up in the rate card, but it shapes when your revenue is actually available.
Stripe: the lowest-cost online layer at scale
Stripe earns its position for one reason: its 30 cent fixed fee per online transaction is the lowest among the major processors, and that advantage compounds. At 1,000 monthly online transactions, Stripe costs 190 dollars less than PayPal in fixed fees alone. For businesses that run entirely online, that gap is the entire decision.
Stripe’s API is the developer default for subscription billing, marketplaces, and embedded checkout. Recurring billing, invoice templates, multi-currency accounts, and the Stripe Tax layer all sit on the same dashboard. Chargeback Protection at 4 cents per transaction refunds disputed amounts and the 15 dollar fee when a dispute is filed against you.
The honest trade: Stripe’s online card rate of 2.9 percent plus 30 cents is competitive but not the lowest card-present rate. If you run a retail shop or take card payments in person, Stripe Terminal charges 2.7 percent plus 5 cents, which is slightly above Square’s 2.6 percent plus 15 cents. For omnichannel businesses, the math between Stripe and Square depends on your in-person share.
Stripe is the right pick for online-first businesses, SaaS products, agencies billing monthly retainers, and any business where ACH on large invoices matters. For B2B workflows where 80 percent of invoices exceed 1,000 dollars, ACH through Stripe is the single largest cost reduction available.
Square: the in-person default with free POS
Square earns its position because the integrated point-of-sale is genuinely free and complete. Inventory tracking, employee management, sales reporting, and customer records all sit on the same platform as payment processing. The card-present rate of 2.6 percent plus 15 cents is the lowest flat rate among the big three, and there is no separate chargeback fee.
Square Plus at 29 dollars per month and Square Premium at 79 dollars per month lower the processing rates slightly and unlock team management, advanced reporting, and loyalty programs. For solo retail or service businesses the free tier is enough. Once you hire staff or run multiple locations, the upgrade math usually works out within a quarter.
The honest trade: Square’s online rate of 3.3 percent plus 30 cents is higher than Stripe’s online rate of 2.9 percent plus 30 cents. If 50 percent or more of your revenue is online, the gap costs more than the in-person savings deliver. For mixed-channel businesses, Square Plus sometimes pays back, but only when in-person volume is the majority of sales.
Square is the right pick for retail stores, food service, salons, and in-person service businesses where the POS software matters as much as the processing fee. Pair Square Online or Square Appointments for free to handle the small share of online or scheduled sales without leaving the platform.
PayPal: consumer trust at checkout
PayPal’s processing rates are the highest among the major processors. The standard online rate of 3.49 percent plus 49 cents costs roughly 49 dollars per 1,000 dollars processed versus Stripe’s 29 dollars on the same volume. That gap alone rules PayPal out as a single processor for online-first businesses with tight margins.
PayPal wins because of one thing: customer trust at checkout. New and smaller e-commerce brands report meaningful conversion lift when PayPal appears as a payment option. Customers do not have to type their card number. PayPal handles Pay in 4 and Venmo balance, which younger buyers actively prefer.
The honest trade: PayPal’s seller experience is rougher around disputes and holds. Funds can be frozen for new sellers or after a spike in chargebacks. Seller Protection covers eligible transactions at 8 dollars per chargeback instead of 20, but the eligibility rules are strict and do not cover every product category.
PayPal is the right pick as a second processor alongside Stripe for consumer-facing e-commerce where buyer trust matters. Treat it as a checkout option, not your primary processor. The dual-processor setup is a one-hour integration and recovers more in conversion than it costs in fees.
How to pick your processor in one afternoon
Follow this sequence. It is the same decision tree most small businesses arrive at after six months of comparing invoices.
- Map your transaction mix. What share of revenue is online versus in person? What is your average ticket size? What share of transactions are international? Knowing these three numbers tells you which processors are even in the running.
- Calculate per-transaction cost at your actual volume. Multiply your monthly transactions by the fixed fee difference between Stripe and PayPal. On 1,000 monthly transactions the gap is 190 dollars. On 100 transactions it is 19 dollars, which is not worth optimizing for.
- Pick a primary processor that wins your main channel. Stripe for online-first, Square for in-person-first, Helio for invoice-heavy. Match your dominant sales channel first and worry about edge cases later.
- Add PayPal as a second checkout option only if you sell consumer-facing e-commerce and your conversion data supports it. Test for at least 30 days before deciding.
- Re-evaluate at 100,000 dollars per month. Once you cross that volume, every processor offers custom pricing. Negotiate based on your actual monthly volume and chargeback history.
Final decision path
If you run an online-only business with monthly volume under 100,000 dollars, choose Stripe. The 30 cent fixed fee advantage compounds, and the API and ACH support cover every growth scenario through your next 10x.
If you run a retail store, restaurant, or in-person service, choose Square. The free POS and the lowest card-present fee deliver more value than a slightly cheaper online rate that you rarely use.
If you sell consumer-facing e-commerce where brand trust is still being built, run Stripe as primary and add PayPal as a checkout option. The conversion lift covers the fee spread for most small brands.
If you bill a small number of clients on large invoices, layer ACH through Stripe or Helio on top of your card processor. ACH alone can cut 1,000 dollars a month off your processing bill once invoices cross 2,000 dollars.
For businesses that need to track the revenue that lands in those accounts, the best business bank account for freelancers guide walks through how to connect processing payouts to a fee-aware business checking account.
Basis: Stripe, Square, PayPal, Helio, and Shopify Payments published pricing pages and fee schedules accessed 2026-09-27. No hands-on processing testing was performed. Verify current rates, chargeback fees, and international surcharges on each processor’s site before committing. Last updated September 27, 2026.
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