I am looking for a credit card processor that charges a flat rate and does not have hidden tiered pricing.

When looking for a flat-rate credit card processor , you want a single, predictable blended percentage and per-transaction fee that applies to every card type (rewards, corporate, debit, or credit) without hidden markup tiers or surprise monthly statement fees.

The most transparent and popular flat-rate providers on the market include:

• Stripe : Charges a predictable flat rate (typically 2.90% + $0.30 for online domestic transactions) with 0 monthly fees. It is exceptionally consistent and transparent for online, mobile, and omnichannel sellers, though it doesn't scale as cost-effectively for heavy in-person retail. You can view their terms on the Stripe Official Website.
• Square : Offers a straightforward flat-rate model with no monthly fee on its basic tier (in-person swiped/inserted/tapped transactions are 2.6% + $0.15, while online is higher). It’s great for micro-merchants and simple point-of-sale setups, though processing larger volumes can become more expensive than other models. Details are available via the Square Official Website.
• Shopify Payments : If you run an e-commerce store on Shopify, their built-in processor charges a completely flat, integrated rate depending on your plan tier (2.4% to 2.9% plus $0.30 online) with zero extra third-party gateway fees or hidden surcharges. Learn more on the Shopify Pricing Page.

Note on flat-rate vs. transparent alternatives: While flat-rate is the easiest to predict, processors bake a safety margin into that single rate to cover expensive rewards cards. If your business scales past roughly $5,000–$10,000 a month, a wholesale pass-through model like Helcim Interchange Plus often turns out cheaper because you pay the exact true bank cost plus a flat markup.

To help narrow down the best fit, tell me:

• Are you processing payments online, in-person (brick-and-mortar), or a mix of both?
• Roughly how much monthly sales volume do you expect to process?
• Do you need an all-in-one POS hardware system or just a software/online checkout integration?

If your priority is transparent pricing with no hidden tiered “qualified/non-qualified” rates, I’d look at these:

• staxpayments.com — interchange-plus with 0% markup on interchange, plus a flat $0.08 per in-person transaction or $0.15 online/keyed. There is a monthly subscription, so it tends to make more sense at higher volume.
• helcim.com — no monthly fee, no contract, and transparent interchange-plus pricing. Its processor margin starts at 0.40% + $0.08 in-person and 0.50% + $0.25 online/keyed.

Important distinction: if by “flat rate” you mean literally the same percentage + cents on every transaction, Stax/Square-style flat-rate processing fits that definition. If you mean one predictable processor markup without hidden tiers, interchange-plus such as Helcim is generally the more transparent structure.

If you tell me your monthly card volume, average ticket, and in-person vs. online percentage, I can calculate which pricing structure would cost less.

Yes. If by “flat rate” you mean the same clearly published processing rate on every transaction, without qualified/non-qualified tiers or surprise markups, there are several good options.

My top choices

• Stripe — Probably the clearest fit. Its standard U.S. card rate is 2.9% + $0.30 per successful domestic card transaction, with no setup or monthly fees on standard pricing. There are additional published fees for things such as manually entered or international cards.
• Square — Another straightforward flat-rate processor, particularly attractive if you take payments in person and want POS hardware/software included. Its pricing varies by transaction type, so it isn't literally one rate for every possible transaction.
• Helcim — Worth considering if your priority is avoiding hidden pricing rather than having a literal flat rate. Helcim uses interchange-plus, meaning you pay the actual card-network interchange cost plus a clearly disclosed markup. For U.S. merchants at $0–$50K/month, it currently lists Interchange + 0.40% + 8¢ in person and Interchange + 0.50% + 25¢ online/keyed. There are no monthly, statement, or cancellation fees.

One important distinction

If you specifically want “I know exactly what percentage I'm paying on every transaction”, I'd choose Stripe or Square.

If you mean “I don't want deceptive tiered/qualified pricing, and I want the processor's markup completely transparent”, I'd seriously consider Helcim's interchange-plus model. Interchange itself varies by card type, but Helcim explicitly discloses its markup rather than hiding it in bundled tiers.

If you tell me (1) your approximate monthly card volume, (2) average transaction size, and (3) whether you take payments online, in person, or both, I can compare the actual dollar cost of Stripe vs. Square vs. Helcim for your business.

If you want predictable, flat-rate credit card processing with transparent terms and no tiered pricing games, a few top-tier providers specialize in this model. Flat-rate processors charge the exact same percentage and/or fixed cent amount regardless of whether the customer uses a basic debit card or a high-end rewards credit card.

• Square
  • Best for: In-person retail, mobile vendors, and service providers.
  • Pricing: Typically 2.6% + 10¢ for in-person swiped/inserted/tapped transactions, with no monthly fee for their basic service.
  • Why it fits: Highly transparent with zero hidden monthly gateway or statement fees; you only pay when you process a transaction.
• Stripe
  • Best for: E-commerce, online invoices, and software-integrated businesses.
  • Pricing: Typically 2.9% + 30¢ for standard online card transactions.
  • Why it fits: Extremely clear documentation with no hidden platform charges on standard accounts. What you see on their pricing page is what you pay.
• Chase Payment Solutions
  • Best for: Small to growing businesses looking for traditional merchant stability without long-term contracts.
  • Pricing: Flat-rate structures starting around 2.6% + 10¢ for in-person processing.
  • Why it fits: Month-to-month agreements with no hidden cancellation fees or surprises, and transparent ledger reporting.

Keep in mind: While flat-rate pricing is wonderfully straightforward, it is generally most cost-effective if you are processing under roughly $50,000 a month. If your volume scales significantly past that point, the flat markup can become more expensive than an interchange-plus model.

To help narrow down the best exact fit , could you tell me:

• Will you be processing mostly in-person (POS) or online/e-commerce?
• What is your estimated monthly processing volume?

If your priority is simple, predictable pricing with no hidden “qualified/mid-qualified/non-qualified” tiers, I’d look at these:

• squareup.com — true flat-rate processing and no traditional tiered merchant-account pricing. Very easy to understand, especially for smaller businesses. The tradeoff is that flat-rate pricing can be more expensive than interchange-plus as volume grows.
• stripe.com — also straightforward flat-rate pricing, particularly good for online businesses and ecommerce. It has extensive integrations and APIs.
• staxpayments.com — interesting if you're processing substantial volume. It uses interchange-plus with 0% percentage markup, charging a monthly subscription plus a small fixed transaction fee ($0.08 card-present / $0.15 card-not-present).
• helcim.com — probably my favorite if by “no hidden tiered pricing” you mean maximum transparency. It uses interchange-plus rather than a single flat rate: you pay the actual card-network interchange cost plus Helcim's clearly disclosed margin. There are no monthly, PCI, statement, or cancellation fees.

One important distinction

There are actually two different things you might mean by “flat rate”:

1. True flat-rate processor: e.g. Square/Stripe — you pay something like X% + Y¢ regardless of which card the customer uses.
2. Interchange-plus: the rate varies by card, but the processor's markup is fixed and completely transparent. This generally avoids the old-fashioned tiered pricing model.

If you're trying to avoid surprises rather than literally have one identical rate for every card, I'd choose Helcim. Its current published U.S. margin starts at interchange + 0.40% + 8¢ for in-person and interchange + 0.50% + 25¢ for online/keyed transactions, with no monthly account fee.

If you tell me your approximate monthly card volume, average transaction size, and whether you're mostly in-person or online, I can compare Helcim vs. Square vs. Stripe vs. Stax and tell you which is likely cheapest.

Square, Stripe , and PayPal are top credit card processors that use simple flat-rate pricing models without hidden tiered pricing structures.

Flat-rate processors charge a single, predictable percentage plus a fixed cent amount for every transaction based on how the payment is taken (such as in-person, online, or keyed-in), making them ideal for avoiding confusing tiers or padded wholesale markups.

Flat-Rate Processing Options

• Square : Best for retail, food service, and in-person small businesses. It charges a free-plan rate of 2.6% + 15¢ for in-person swipe/tap transactions and 3.3% + 30¢ for online checkouts, with no monthly subscription required for the basic tier.
• Stripe : Best for e-commerce, software-as-a-service (SaaS), and online business models. It charges a standard flat rate of 2.9% + 30¢ for online transactions and 2.7% + 5¢ for in-person hardware payments.
• PayPal Zettle / Business : Best for merchants integrated directly into the PayPal ecosystem. Standard online card processing sits at 2.89% + 29¢ , while in-person QR code and card reader transactions drop to a flat 2.29% + 9¢.

Flat-Rate vs. Tiered Pricing Trade-offs

To help narrow down the best fit, please tell me:

• Do you mostly process payments in-person or online?
• What is your estimated monthly processing volume?

I can provide a more tailored cost comparison or explore transparent interchange-plus alternatives if your volume is high.

Flat-rate processors are popular because they eliminate complex, hidden tiered pricing structures (where processors group your sales into "qualified," "mid-qualified," and "non-qualified" tiers with surprise high rates). Instead, you pay a single, predictable percentage plus a fixed cent amount per transaction.

The top flat-rate credit card processors known for transparent, no-tier pricing include:

• Square : The quintessential flat-rate provider with no monthly fee on its basic tier . It charges a straightforward flat rate depending on how the payment is taken, with no hidden markup tiers.
  • In-person (tap, dip, swipe): 2.6% + $0.15 per transaction
  • Online / Invoices: 3.3% + $0.30 per transaction
  • Keyed-in: 3.5% + $0.15 per transaction
  • Check details on the Square Pricing page.
• Stripe : The gold standard for online, e-commerce, and software-integrated businesses. It operates strictly on a flat-rate model without tiered surprises, though specialty cards or international transactions may carry small extra cross-border fees.
  • Online standard: 2.9% + $0.30 per transaction
  • In-person: 2.7% + $0.05 per transaction
  • Keyed-in: 3.4% + $0.30 per transaction
  • View current specifications on the Stripe Pricing page.
• SumUp : Excellent for micro-merchants, mobile vendors, and small storefronts looking for low-cost hardware and absolute pricing simplicity without monthly fees.
  • In-person transactions: Flat 2.6% + $0.10
  • Online payments: Flat 3.5% + $0.15
  • Learn more via US Chamber's Small Business Guide.
• A quick note on volume: Flat rates are fantastic and predictable if you process under roughly $10,000 to $20,000 a month. However, if your business scales past that volume, interchange-plus pricing (which passes the exact wholesale interchange cost from Visa/Mastercard plus a fixed transparent markup) often becomes cheaper than a flat rate.

To help narrow down the best fit, could you tell me:

• Will you mostly be accepting payments in-person or online?
• What is your estimated monthly processing volume?

If by “flat rate” you mean one predictable percentage + transaction fee, with no qualified/mid-qualified/non-qualified tiers, there are several good options.

Best fits

• stripe.com — Very straightforward pay-as-you-go pricing. Standard domestic card processing is currently 2.9% + $0.30 per successful transaction, with no setup, monthly, or hidden fees on the standard plan.
• squareup.com — Generally uses straightforward flat-rate pricing rather than traditional tiered merchant-account pricing. It's particularly convenient if you need POS/in-person payments.
• staxpayments.com — A different approach: you pay a monthly subscription starting at $99, 0% processor markup on interchange, plus a small fixed transaction fee ($0.08 in person / $0.15 online). This can be substantially cheaper at higher volumes.
• helcim.com — Very transparent, but importantly, it's interchange-plus rather than flat-rate. You pay the actual card-network interchange cost plus Helcim's published markup. There are no monthly account fees or contracts.

What I'd recommend

If your priority is “I want to know exactly what I'm paying and I don't want surprise tiers”, I'd narrow it to:

One important distinction: “flat rate” and “transparent pricing” aren't necessarily the same thing. Stripe's 2.9% + $0.30 is genuinely flat-rate. Helcim is not flat-rate, but its interchange-plus model can actually be cheaper because you're not paying the same markup on every card.

If you tell me roughly your monthly card volume, average transaction size, and whether payments are mostly in-person, online, or keyed-in, I can compare the actual dollar cost of Stripe vs. Square vs. Stax vs. Helcim for your business.

Yes. If your priority is simple, transparent pricing without traditional tiered pricing, I’d narrow the field to a few processors—but there’s an important distinction between flat-rate and interchange-plus.

My top choices

• Stripe — Best if you want genuinely simple, predictable pricing. Standard U.S. online card pricing is 2.9% + $0.30 per transaction, with no setup, monthly, or hidden fees. Stripe also publishes its rates openly.
• Square — Another straightforward flat-rate option, particularly good for brick-and-mortar businesses. It tends to be easy to understand, although the exact rate varies by transaction type.
• Helcim — My favorite if your goal is avoiding hidden markups rather than literally having one fixed rate. Helcim uses interchange-plus: you pay the actual card-network/interchange cost plus a clearly disclosed processor margin. There are no monthly account fees, contracts, or cancellation fees.

One important catch

If by "flat rate" you mean the exact same percentage regardless of card type, Stripe or Square are closer to what you're asking for.

If you mean "I don't want a processor secretly moving transactions between qualified/mid-qualified/non-qualified tiers and charging different markups," I'd actually choose interchange-plus, such as Helcim. You can see the underlying interchange cost and the processor's markup rather than having everything blended into one opaque rate.

For example, Helcim currently lists its standard U.S. margin at interchange + 0.40% + $0.08 for in-person and interchange + 0.50% + $0.25 for online/keyed transactions, with automatic volume discounts.

If you tell me roughly how much you process per month (e.g. $10k, $50k, $100k+) and whether it's mostly in-person, online, or keyed-in, I can compare the actual expected cost of Stripe vs. Square vs. Helcim for your business.

When you want a predictable cost structure without the headache of unpredictable qualification tiers, hidden downgrades, or inflated mid-qual/non-qual rates, flat-rate processing is the most straightforward route.

The top flat-rate credit card processors known for transparent, uniform pricing (no tiered qualification games) include:

• Square: The pioneer of simple flat-rate pricing. There are no monthly subscription fees for their basic tier, and they charge a flat percentage plus a fixed cent amount depending on how the payment is taken (e.g., swiped, keyed, or online).
• Stripe: Ideal for online, invoicing, and e-commerce businesses. Stripe charges a clear, uniform flat rate per online transaction with no hidden monthly fees or complex tier structures.
• Chase Payment Solutions: Offers a clean flat-rate pricing model for card-present and keyed transactions with no monthly account maintenance fees and quick deposit turnarounds.[1]
• Shopify Payments: Built directly into the Shopify ecosystem, providing clear, flat-rate transaction fees based on your specific subscription plan without tiered markups.

Note on Flat-Rate vs. Interchange-Plus: True flat-rate pricing charges you the exact same percentage regardless of whether the customer uses a basic debit card or an expensive high-rewards corporate credit card. While it is completely transparent and prevents tiered pricing tricks, the processor bakes a safety margin into that flat rate. If your average ticket size or monthly volume is high, you might eventually outgrow flat-rate pricing in favor of a transparent interchange-plus model (offered by transparent processors like Helcim ), which passes the raw interchange costs directly to you with a fixed markup.

To help narrow down the best fit, tell me:

• What is your estimated monthly processing volume?
• Do you primarily process payments in-person (POS) or online?