Choosing Software

Choosing how to accept payments is one of the first decisions that directly touches your cash flow, so it's worth getting right from day one. The wrong processor can cost you thousands a year in unnecessary fees, freeze payouts without warning, or leave you exposed when chargebacks hit.

What a payment processor does

A payment processor is the plumbing behind every card transaction. When a customer pays, the processor authorizes the card, routes the money through the card networks (Visa, Mastercard), and eventually deposits funds into your bank account.

People often use "payment processor," "payment gateway," and "merchant account" as if they mean the same thing. They don't:

Payment gateway: The secure tunnel that encrypts card data and passes it between your checkout and the processor.
Payment processor: The company that actually moves the money (authorization, capture, settlement).
Merchant account: A holding account at an acquiring bank where funds sit before depositing into your business bank account.

Modern all-in-one providers like Stripe, Square, and PayPal bundle all three roles together. That simplifies setup but means if one piece of their infrastructure has a problem, every piece does. Traditional setups separate these layers, which gives you more control but also more contracts to manage.

Key Facts:

Global digital payments transaction value is projected to reach $26.89 trillion in 2026 (Statista, 2026).

The average chargeback rate reached 0.26% in Q3 2025, up 53% from Q1 2025 (Chargeback.io, 2025).

Friendly fraud accounts for roughly 75% of chargeback cases, making dispute tools a critical processor feature (Mastercard/Datos Insights, 2025).

What to look for

Use this table as a scoring sheet when you compare processors. Weight the criteria by what your business actually needs.

Criterion	Why it matters	What good looks like
Fee structure	Your effective rate compounds fast at volume; flat-rate vs. interchange-plus can swing costs by 30-50% for high-volume merchants	Transparent published rates; interchange-plus available at scale; no surprise monthly minimums
Payment methods accepted	Customers pay how they prefer, not how you prefer	Cards (Visa/MC/Amex/Discover), digital wallets (Apple Pay, Google Pay), ACH/bank transfers, buy-now-pay-later options
Payout speed	Cash flow depends on when funds land in your account	Standard 1-2 day ACH settlement; instant payout option (usually for a fee) available if you need same-day
PCI DSS compliance	A breach without Level 1 PCI compliance can mean network fines, fraud liability, and loss of card-acceptance rights	Processor is certified PCI DSS Level 1 and provides a hosted payment page or tokenization to keep card data off your servers
Fraud and chargeback tools	Chargebacks cost more than the disputed transaction: fees typically run $15-$100 per dispute on top of the refund	Radar/rule-based fraud scoring, 3D Secure support, chargeback alerts (Ethoca/Verifi), dispute management dashboard
Developer and API quality	If you have a dev team, API quality determines how fast you ship and how reliably you run	REST API with SDKs in your stack's language, Stripe-grade documentation, sandbox/test environment, webhooks for real-time events
International and multicurrency	Currency conversion and cross-border fees can easily add 1-2% per transaction	Local acquiring in key markets, dynamic currency conversion controls, multi-currency payouts, clear FX markup disclosure
Subscriptions and recurring billing	Subscription logic inside the processor means fewer tools and less revenue leakage	Native subscription management, dunning logic, smart retries, proration, invoice customization

Key questions to ask before you buy

Run any shortlisted processor through these questions before you sign up.

What is your effective rate for my business type? Ask for a sample statement from a similar merchant; the published rate is a floor, not an average.
How do you handle account terminations and fund holds? Processors can freeze accounts with 24-hour notice. Ask for their risk policy in writing and what triggers a hold.
What is your chargeback threshold before you flag my account? Most networks trigger a review at 1%; some processors act at 0.5%. Know the line before you cross it.
Do you support the payment methods my customers expect? If you sell internationally, confirm local payment methods (SEPA, iDEAL, Pix, Konbini) are supported in your target markets.
What does PCI compliance look like with your integration? A hosted payment page or tokenization keeps card data off your servers and simplifies your audit scope. Ask if they provide a SAQ-A path.
What is your dispute resolution process and win rate? Some processors offer managed chargeback services; others hand you a portal and wish you luck. Ask for average dispute resolution times.
Are there contractual volume commitments or early termination fees? Month-to-month is standard in modern processors; anything with a multi-year term needs careful review.
What does your uptime SLA look like, and what is your incident communication process? Payment infrastructure downtime is lost revenue. Ask for historical uptime data and how they notify merchants during incidents.

Top options at a glance

These are the processors most businesses evaluate. Fees shown are approximate for US card-present or card-not-present transactions. Always verify on the vendor's pricing page before committing.

Processor	Best for	Fee model	Starting fee (approx.)
Stripe	Developers, SaaS, global startups	Flat-rate (interchange-plus for enterprise)	~2.9% + $0.30 per online transaction
Square	Retail and food and beverage, in-person focus	Flat-rate	~2.6% + $0.10 in-person; ~2.9% + $0.30 online
PayPal / Braintree	Marketplaces, consumer-facing checkout	Flat-rate (Braintree: interchange-plus at scale)	~3.49% + $0.49 (PayPal Checkout); Braintree: ~2.59% + $0.49
Adyen	Enterprise, high-volume, global operations	Interchange-plus (IC++)	Interchange + ~0.60% + $0.13 per transaction
Helcim	SMBs wanting interchange-plus without enterprise minimums	Interchange-plus with volume discounts	Interchange + ~0.15-0.50% depending on volume
Checkout.com	High-growth tech companies, global scale	Interchange-plus, custom pricing	Custom; typically competitive with Adyen at volume
Authorize.net	Established businesses, existing bank relationships	Per-transaction plus gateway fee	~2.9% + $0.30 plus $25/month gateway fee
Worldpay	Enterprises needing omnichannel (in-store + online + phone)	Custom, interchange-plus	Custom; contact sales

For the full head-to-head comparison, see the best Stripe alternatives.

How to choose: a decision framework

Map your situation to the criteria that matter most.

Your situation	Prioritize	Consider avoiding
Early-stage startup, under $10K/month in revenue	Stripe or Square: no monthly fees, fast setup, no contracts	Adyen or Worldpay: enterprise minimums, long onboarding
SaaS or subscription business	Native recurring billing, dunning, smart retries, proration (Stripe Billing, Recurly on top of Braintree)	Processors with weak subscription tooling and no retry logic
High-volume retail or ecommerce ($500K+/year)	Interchange-plus pricing (Adyen, Helcim, Braintree): effective rates typically 20-40 basis points lower than flat-rate at scale	Flat-rate-only processors: you leave real money on the table above this volume
Global business, multiple currencies	Local acquiring in target markets, transparent FX markup, multi-currency payouts (Checkout.com, Adyen, Stripe)	Processors that only acquire in the US: cross-border fees stack up fast
Brick-and-mortar retail, high in-person volume	Integrated POS hardware, fast settlement, low card-present rates (Square, Helcim)	Developer-first processors with poor hardware support
High-risk industry (supplements, travel, gambling)	Processors that explicitly support your MCC code, preferably with dedicated risk management	General-purpose processors: sudden account freezes are common in high-risk categories
Marketplace or platform business	Split-payment and payout routing (Stripe Connect, Adyen for Platforms, Braintree)	Single-merchant processors with no sub-merchant infrastructure

Pricing: what to expect

Flat-rate vs. interchange-plus

Flat-rate means you pay one fixed percentage plus a fixed cent amount per transaction, regardless of what card the customer uses. It's predictable and simple. Stripe's published rate of around 2.9% + $0.30 per online transaction is the benchmark (compare the published PayPal business fees and Square fees before you assume one is cheaper). You pay the same whether the customer uses a basic debit card (cheaper for the network) or a premium rewards card (more expensive). At low volumes, that predictability is worth it.

Interchange-plus (also called cost-plus or IC++) passes the actual interchange rate from the card network through to you, then adds a fixed processor markup on top. Because interchange varies by card type (debit cards run around 0.05-0.80%, premium rewards cards can hit 1.5-2.5%), your effective rate varies. But for high-volume businesses, the average usually comes in well below the flat-rate equivalent, often by 20-50 basis points.

Adyen's IC++ model, for example, starts around interchange + 0.60% + $0.13 per transaction. At $1M/month in processing, that difference in basis points translates to tens of thousands of dollars annually.

Hidden costs to budget for

Beyond the headline per-transaction rate, budget for:

Chargeback fees: Typically $15-$25 per dispute filed, whether you win or lose. High-dispute industries pay more.
Currency conversion markup: Most processors add 1-1.5% on cross-border or currency-conversion transactions on top of the base rate. Check whether this is disclosed as a separate line item.
Monthly gateway or account fees: Some processors (Authorize.net, some acquirer-backed solutions) charge $10-$25/month for gateway access.
Instant payout surcharges: Stripe charges around 1.5% (minimum $0.50) for payouts in under 30 minutes. Factor this in if cash flow timing is a regular concern.
PCI non-compliance fees: If you don't complete your annual PCI assessment, some processors charge $10-$50/month in non-compliance fees. Easy to avoid; easy to miss.

For more on evaluating total cost, see the guide on TCO modeling for SaaS purchases.

Frequently asked questions

What is the difference between a payment gateway and a payment processor?

A payment gateway encrypts and transmits card data from your checkout to the processor. A payment processor authorizes the transaction and moves money between the customer's bank and your merchant account. Modern all-in-one providers (Stripe, Square) bundle both into a single product. Older setups use separate vendors for each layer, which gives you more control at the cost of more complexity.

Do I need a merchant account separately?

Not if you use an aggregator like Stripe, Square, or PayPal. These companies pool merchants under a shared master merchant account, which is why setup takes minutes. The trade-off is that they have more latitude to hold or freeze funds under their risk policies. A dedicated merchant account from a traditional bank or ISO takes longer to set up but is harder to freeze unilaterally.

What is PCI DSS and why does it matter?

PCI DSS (Payment Card Industry Data Security Standard) is the set of security controls required by Visa, Mastercard, and other networks for any business that stores, transmits, or processes card data. Non-compliance doesn't usually trigger immediate fines, but after a breach it can mean network penalties, fraud liability, and loss of card-acceptance rights. The easiest path to compliance is using a processor's hosted payment page or tokenization so card data never touches your own servers. See PCI Security Standards Council for the full standard.

How do I reduce chargebacks?

Prevention is cheaper than fighting disputes. Use 3D Secure (Verified by Visa, Mastercard Identity Check) for risky transaction types. Make sure your billing descriptor matches your brand name (unrecognized charges are the top reason customers initiate disputes). Enable chargeback alert services like Ethoca or Verifi if your processor offers them. And respond quickly to every dispute with transaction evidence and customer communication records.

Can I switch processors later without disrupting subscriptions?

Yes, but it takes planning. If you use Stripe Billing or another processor-native subscription tool, your customer payment methods are tokenized to that processor's vault. You'll need to migrate tokens (some processors offer token portability; others don't) or ask customers to re-enter card details. Plan a migration window and test with a small customer cohort first. This is why token portability should be on your checklist when you evaluate a processor you plan to grow with.

Making the call

Payment processing isn't a set-and-forget decision, but it also doesn't need to be agonizing. Start with the fee model that fits your current volume, confirm the payment methods your customers expect, and verify the PCI compliance path before you build. Then revisit the decision when you cross meaningful revenue thresholds ($10K, $100K, $500K monthly), because the right answer at seed stage often isn't the right answer at scale.

If you're also building out the finance stack around payments, see how to choose accounting software and how to choose accounting software for small business for the adjacent buying decisions. And for the full ranked list of processors, start with the best Stripe alternatives to compare head-to-head.

Calvin D.

Head of Enterprise Solutions