"No monthly fee" is true of all four systems here and tells you almost nothing. A POS with no subscription is paid for by the card payments that go through it, so the number to compare is what you pay per payment, at your volume. We read each vendor's own US pricing page on October 27, 2026; no hands-on trial sits behind this page.
What each one charges instead
| System | Monthly fee | In-person card rate (published) | Cheapest reader (published) |
|---|---|---|---|
| Square (Square Free) | $0 | 2.6% + 15¢ | Not in our dated record |
| Helcim | $0 | Interchange + 0.40% + 8¢ | Card reader $199 |
| PayPal Zettle (PayPal POS) | $0 | 2.29% + 9¢ | First card reader $29 |
| Stripe Terminal | $0 | 2.7% + 5¢ | Stripe Reader M2 $59 |
A worked month
Assume a shop taking $20,000 a month in in-person card sales over 800 payments (our example, not a benchmark), at list rates:
| System | Percentage part | Per-payment part | Card fees for the month |
|---|---|---|---|
| Square Free | 2.6% of $20,000 = 520 | 800 × 15¢ = 120 | $640 |
| PayPal Zettle | 2.29% of $20,000 = 458 | 800 × 9¢ = 72 | $530 |
| Stripe Terminal | 2.7% of $20,000 = 540 | 800 × 5¢ = 40 | $580 |
| Helcim | 0.40% of $20,000 = 80 | 800 × 8¢ = 64 | $144 of Helcim markup, plus interchange and card-network fees |
Helcim's line is not comparable at face value: its base cost, interchange paid to the card-issuing bank plus card-network fees, comes on top of its markup and varies with the card mix, so Helcim does not publish a single all-in number. Its advantage is that its own markup is small and visible; whether the total beats a flat rate depends on your cards. Ask Helcim for a statement analysis on your real month.
Our pick: Square Free
For a small merchant who wants a complete point of sale for $0 a month, Square Free is the default: a full POS, not just a reader, on the plan that costs nothing. Square lists Plus at $49 and Premium at $149 per location a month, so you can move up later without changing systems. In the worked month above Square costs about $110 more than PayPal Zettle; on Square's own positioning, that buys a complete POS, payments, hardware and business software in one ecosystem rather than a checkout app.
- Pick Helcim instead once card volume is steady and large enough that the markup matters more than simplicity.
- Pick PayPal Zettle instead for a market stall or a pop-up: a published first-reader price of $29 and the lowest percentage among the three flat-rate offers (PayPal POS, Square Free and Stripe Terminal); Stripe Terminal's smaller per-payment fee wins only on very small tickets.
- Who should skip all of these: a restaurant that needs a kitchen workflow, and anyone who wants a turnkey POS from Stripe Terminal: without code, Stripe's Dashboard app takes Tap to Pay payments, but a POS with a catalog needs your own integration or a third-party POS.
For what a full system costs beyond card fees, see how to calculate the total cost of a POS system.
Traceable evidence
Sources for this decision
- vendorSquare official product siteSquare · checked Aug 5, 2026 · supports: Vendor-published product scope used to verify capabilities relevant to this buyer context: Small merchants evaluating an integrated POS, payment, hardware, and business-software ecosystem. It does not prove the guide's fit verdict, configured performance, current pricing or compliance.Open source ↗
- vendorHelcim official product siteHelcim · checked Aug 5, 2026 · supports: Vendor-published product scope used to verify capabilities relevant to this buyer context: US and Canadian merchants evaluating payments and POS economics together. It does not prove the guide's fit verdict, configured performance, current pricing or compliance.Open source ↗
- vendorPayPal Zettle official product sitePayPal Zettle · checked Aug 5, 2026 · supports: Vendor-published product scope used to verify capabilities relevant to this buyer context: Small and mobile sellers evaluating a straightforward PayPal-connected in-person checkout. It does not prove the guide's fit verdict, configured performance, current pricing or compliance.Open source ↗
- vendorStripe Terminal official product siteStripe Terminal · checked Aug 5, 2026 · supports: Vendor-published product scope used to verify capabilities relevant to this buyer context: Software-led businesses evaluating developer-controlled in-person payments within a Stripe stack. It does not prove the guide's fit verdict, configured performance, current pricing or compliance.Open source ↗
- vendorSquare pricing pageSquare · checked Oct 27, 2026 · supports: Square's own pricing page as read on 2026-10-27, supporting the entry list price of its Square Free plan ($0/month software; 2.6% + 15¢ in person) and the page details recorded with it (Plus $49 and Premium $149 per location/month), and a free plan (Yes, Square Free). It does not prove the total cost for a given buyer, later price changes, promotions, negotiated discounts or taxes.Open source ↗
- vendorHelcim pricing pageHelcim · checked Oct 27, 2026 · supports: Helcim's own pricing page as read on 2026-10-27, supporting the entry list price of its Pay-as-you-go plan ($0/month; interchange + 0.40% + 8¢ in person) and the page details recorded with it (Card reader $199), and a free plan (Yes, no monthly fee). It does not prove the total cost for a given buyer, later price changes, promotions, negotiated discounts or taxes.Open source ↗
- vendorHelcim, interchange-plus pricing explainedHelcim · checked Oct 27, 2026 · supports: Helcim's interchange-plus page explaining that the base cost is a variable fee made up of interchange fees paid to the card-issuing bank and card-network fees, with Helcim's margin added on top; it does not prove a total cost for a given merchant.Open source ↗
- vendorPayPal Zettle pricing pagePayPal Zettle · checked Oct 27, 2026 · supports: PayPal Zettle's own pricing page as read on 2026-10-27, supporting the entry list price of its PayPal POS plan ($0/month; 2.29% + 9¢ in person) and the page details recorded with it (First card reader $29), and a free plan (Yes, free POS app). It does not prove the total cost for a given buyer, later price changes, promotions, negotiated discounts or taxes.Open source ↗
- vendorStripe Terminal pricing pageStripe Terminal · checked Oct 27, 2026 · supports: Stripe Terminal's own pricing page as read on 2026-10-27, supporting the entry list price of its Pay-as-you-go plan ($0/month; 2.7% + 5¢ in person) and the page details recorded with it (Developer platform; Stripe Reader M2 $59), and a free plan (Yes, no monthly fee). It does not prove the total cost for a given buyer, later price changes, promotions, negotiated discounts or taxes.Open source ↗
- vendorStripe docs: accept in-person payments without codeStripe · checked Oct 28, 2026 · supports: Stripe's documentation as read on October 28, 2026: three no-code ways to accept in-person payments, including Tap to Pay in the Stripe Dashboard mobile app on iOS (iPhone XS or later, passcode and iCloud sign-in) or a supported Android device with NFC, for contactless cards and NFC wallets, priced under Stripe's pay-as-you-go Terminal and Tap to Pay pricing; it does not state the US Tap to Pay fee or describe a catalog-based POS.Open source ↗