The cheapest rate on a processor’s sales page may not be the cheapest way to run your business. A coffee shop with hundreds of small tap-to-pay sales, a contractor sending a few large invoices, and an online store taking orders overnight put very different demands on a payment system. The fixed cents-per-transaction fee alone can change which quote wins.
Start with how customers pay you, then compare the full cost of taking those payments. Payout timing, software fit, support, and the terms for leaving matter just as much as the headline card rate.
Map your sales before comparing processors
Pull a recent month of sales and note your total card volume, number of transactions, average sale, and share taken in person, online, by invoice, or over the phone. If you’re opening a new business, make a realistic estimate and revisit it after your first few statements.
List the jobs the system must handle: a counter checkout, mobile payments at customers’ homes, online orders, deposits, recurring bills, or a mix. Then separate necessities from features you might use someday. A polished online checkout won’t help much if staff can’t split a restaurant bill quickly; a good card reader won’t solve an online store’s inventory problems.
You may see several terms in a quote. A merchant account is part of the arrangement for accepting and settling card payments. A payment gateway handles the secure exchange of online payment information. Many providers package processing, a gateway, and business software together, so you may not need to buy each separately. The question is less “Which pieces do I need?” than “Does this particular package work with the way I sell?”
Compare the cost of your actual transactions
Flat-rate pricing is easy to forecast: each eligible sale costs a stated percentage plus a fixed amount. Interchange-plus pricing passes through underlying card and network costs, then adds the processor’s markup. Its final rate varies with the cards customers use and how payments are accepted. Neither model is automatically cheaper for every business.
The published U.S. rates below show why it pays to compare channels, not just companies:
- On its Free plan, Square charges 2.6% plus 15¢ for an in-person tap, dip, or swipe, and 3.3% plus 30¢ for an online card or invoice payment. Square Free has no monthly subscription cost; paid plans have different rates.
- Stripe’s standard domestic-card rate is 2.9% plus 30¢ online; its published in-person card rate is 2.7% plus 5¢. Stripe’s standard payments pricing has no setup or monthly fee, though particular products and payment methods can carry additional charges.
- Helcim uses interchange-plus pricing. At up to $50,000 in monthly card volume, its published markup is 0.40% plus 8¢ in person or 0.50% plus 25¢ for keyed and online payments, on top of interchange and network costs. It lists no account monthly fee or cancellation fee.
On a $10 in-person sale, those published flat rates work out to 41¢ with Square Free and 32¢ with Stripe, before any other applicable costs. Across 500 such sales, that’s a $45 difference. But a business shouldn’t switch based on that calculation alone: it still needs a compatible checkout setup, and its mix of sales may produce a different result.
Ask each finalist for a written estimate using your monthly transaction count, average ticket, and split by payment type. Have it include monthly software or gateway charges, readers and terminals, chargebacks, refunds, manually entered cards, international cards, and any add-ons you’ll use. For interchange-plus quotes, request an estimate based on your card mix or an analysis of a recent processing statement. An advertised markup isn’t your total rate.
Look especially hard at small tickets. A 10¢ difference in the fixed fee costs $100 across 1,000 sales, whatever the percentage rate. For large invoices, the percentage and the availability of a suitable bank-payment option may matter more.
Check when sales become usable cash
“Daily payouts” can mean the processor sends money daily—not that today’s sale reaches your bank today. Ask when the payout clock starts, the daily cutoff, how weekends affect transfers, and what happens during your first weeks of processing.
Square’s standard transfers generally reach a linked bank account the next business day for payments taken before its cutoff; later payments can take another business day. Its instant-transfer option costs an additional 1.95% per transfer and has limits for new sellers. Stripe says a first payout commonly takes 7–14 days, even though later payouts can follow a more frequent schedule. Helcim describes standard card deposits as generally arriving one to two business days after batch settlement; eligible U.S. merchants can get next-business-day funding when their bank and batch timing qualify.
A fast advertised schedule is useful, but don’t build payroll around the best-case arrival time. Ask how the provider handles account verification, unusually large sales, disputes, and reviews that might delay a payout. If you rely on Friday’s receipts to buy Monday’s inventory, run a small real payment and watch when the funds actually arrive before moving all your sales.
Make the software prove it fits
The processor should work with your checkout and back office without creating a second round of data entry. Test the exact workflow you’ll use: make a sale, issue a partial refund, find the transaction, and match the payout to a day’s orders. Check that sales tax, tips, discounts, and multiple locations appear correctly in the reports you need.
An integration claim needs a closer look. Ask whether your particular website plan, POS version, booking system, or accounting package supports the processor—not merely whether the companies appear in each other’s app directories. Find out whether syncing includes individual sales and fees or only a daily total. That distinction can decide how long bookkeeping takes each week. If you’re choosing that system too, the guide to choosing accounting software for a small business can help you decide which records you need it to receive.
Your selling platform may also change the price of an outside processor. On Shopify, for example, using a third-party payment provider can trigger Shopify transaction fees in addition to that provider’s processing charges; the fee depends on the Shopify plan. If you already sell there, compare the combined cost with Shopify Payments before deciding that an outside card rate is lower.
For an online store, test checkout on a phone and confirm that refunds and order status flow back to the store. For a service business, send a test invoice and see what the customer receives and what your staff must do when it’s paid. For in-person sales, check reader compatibility, connectivity, and what happens when the internet fails. These tests expose costs that a rate sheet cannot.
Judge support by the hours you need it
A phone number isn’t a support plan. If most of your sales happen on Saturday night, weekday phone support may leave you handling a failed terminal alone. Check the hours and channels included with your plan, whether payment holds and chargebacks go to a separate team, and how an urgent case is escalated.
The differences can be concrete: Square lists different phone-support hours across its Free, Plus, and Premium plans, while Helcim lists phone hours on weekdays and Saturdays. Stripe advertises 24/7 email, chat, and phone support for its payments product. Published availability is a starting point, not a promise of instant resolution. Contact each finalist with a specific question about your setup and see how clearly it answers.
Read the exit terms before signing
A month-to-month processing arrangement can still leave you with a separate equipment obligation. Ask who owns the reader or terminal, whether a lease is cancellable, what happens to stored customer payment details if you leave, and whether you can export transaction records in a usable format. Get the rules for price changes, account closure, and any early-termination charge in writing.
Be especially wary when a salesperson wants a signature before providing the full documents. The Federal Trade Commission warns about processing and equipment-lease offers that use fine print or misleading promises. A lower quoted rate is no bargain if the equipment commitment costs more than the savings.
Security deserves one direct question, too: which card-data tasks does the provider handle, and which remain yours? Outsourcing card processing can reduce your workload, but the PCI Security Standards Council says it does not remove every merchant responsibility. Confirm the obligations for your setup rather than assuming a hosted checkout takes care of everything.
Choose the best fit, then verify it with a small launch
For a straightforward counter or mobile setup, start by testing a processor whose POS and payments work together. For a business built around a custom website, put checkout integration high on the list. If card volume is substantial enough that small rate differences add up, get an interchange-plus quote and compare its estimated total, not just its markup. If you already use an ecommerce platform, price its built-in option before adding an outside provider.
Narrow the field to two finalists. Give each the same sales profile and ask for its full estimated monthly cost, expected first and ongoing payout times, required equipment and integrations, support access, and cancellation terms. Then process a few real sales, including a refund, and reconcile the deposits. The right processor is the one that gets those everyday jobs done reliably at a cost you can explain—not simply the one with the lowest number in an ad.