The three numbers behind a card rate

Three published numbers decide what taking a card costs you: the percentage of each sale, the flat fee on each transaction, and the fixed monthly cost. The third one is why two shops on the identical plan pay very different shares of their takings.

A pricing page usually leads with one figure. What you pay is that figure, plus a flat fee, plus whatever the provider charges every month whether you sell anything or not. Every provider on the provider list is recorded with all three, or with a note naming the one that is missing.

The percentage is the number on the poster

Square publishes 2.60% for a card-present sale in the US and 1.75% in the UK (checked 2026-08-25). SumUp publishes 1.69% for UK card reader payments (checked 2026-08-25). Dojo publishes an all-in blended 1.20% for businesses under £100,000 of annual turnover (checked 2026-08-25). This number behaves the same at every level of sales. It is the only one of the three that does not shift as your takings grow.

The flat fee is small until you look at your average sale

Square adds $0.15 to each US card-present sale, PayPal (Zettle) adds $0.09, and Stripe adds $0.05 (checked 2026-08-25). A flat fee is a larger share of a cheap sale than of an expensive one. This site assumes an average sale of $25.00 in the US and £20.00 in the UK. That is the only figure on the site that no provider published. On Square's free US plan the flat fee turns a headline 2.60% into an effective 3.20%, a gap of 0.60 percentage points (checked 2026-08-25).

The fixed monthly cost is the number that moves

Plan fees, terminal rental, and a published minimum monthly charge all behave alike. They cost the same dollars whether you take $5,000 or $50,000 in a month. Square Premium is $149 a month, SumUp's POS with Connect Plus is $199 a month, and Shopify Advanced is $399 a month (checked 2026-08-25).

Why does one plan cost 5.98% for one shop and 3.30% for another?

Because the same $149 is divided by a different amount of sales. Square Premium publishes 2.40% + $0.15 card present with a $149 monthly fee (checked 2026-08-25). Start with the shop taking $5,000 a month, which is 200 sales at an average of $25.00.

$5,000 x 2.40% = $120.00 200 x $0.15 = $30.00 plan fee = $149.00 total = $299.00 $299.00 / $5,000 = 5.98%

That shop hands over 5.98% of its card takings (checked 2026-08-25). Now the shop taking $50,000 a month, which is 2,000 sales at the same average.

$50,000 x 2.40% = $1,200.00 2,000 x $0.15 = $300.00 plan fee = $149.00 total = $1,649.00 $1,649.00 / $50,000 = 3.30%

That shop hands over 3.30% (checked 2026-08-25). Neither the percentage nor the flat fee changed between the two calculations. The $149 fell from 2.98% of sales to 0.30% of sales, and that is the whole of the difference. The distance between a headline figure and a total is the subject of what the headline rate leaves out.

The same three numbers across six US plans

Effective rate over 36 months at an average sale of $25.00, from each provider's own published US pricing page (checked 2026-08-25).
PlanPublished card-present rateFixed monthly costAt $5,000 a monthAt $50,000 a month
Square Free2.60% + $0.15$03.20%3.20%
SpotOn All-In2.79% + $0.20$03.59%3.59%
Square Premium2.40% + $0.15$1495.98%3.30%
SumUp POS with Connect Plus2.60% + $0.10$1996.98%3.40%
Lightspeed Retail Plus1.50%, no per-sale fee published$2897.28%2.08%
Shopify Advanced2.40% + $0.10$39910.78%3.60%

Lightspeed Retail Plus carries the lowest percentage in the table, 1.50% (checked 2026-08-25). At $5,000 a month it is the second dearest of the six, at 7.28% against Shopify Advanced's 10.78%. At $50,000 a month it is the cheapest, at 2.08% (checked 2026-08-25). The two plans with no monthly fee do not move at all. Square Free stays at 3.20% and SpotOn All-In stays at 3.59% (checked 2026-08-25).

The effective rate calculator runs this arithmetic against your own monthly card sales.

A minimum monthly charge is a fixed cost under another name

Some providers publish a floor. If your percentage and flat fees fall short of the floor, you pay the floor. It behaves exactly like a plan fee. Paymentsense (Nexi) publishes a minimum monthly service charge of £24.95 (checked 2026-08-25). Its terminal is £20.00 a month, with 1.40% on debit and credit cards and a £0.05 authorisation fee (checked 2026-08-25).

At an average sale of £20.00, that plan works out at 2.15% on £5,000 a month and 1.70% on £50,000 (checked 2026-08-25). Cardnet (Lloyds Bank) publishes a £10 minimum monthly charge on its Castles Saturn terminal, which rents for £23 a month plus VAT (checked 2026-08-25). That plan works out at 1.11% on £5,000 a month and 0.70% on £50,000 (checked 2026-08-25).

Read a pricing page in this order

Find the percentage first, because it is always there. Then look for the flat fee, which often sits in a footnote or does not appear at all. Then add every fixed monthly line you can see: plan fee, terminal rental, PCI fee, and minimum monthly charge. That order matches the one used in what card payments cost.

Where the answer changes

Who this article is not for

This does not help you if your provider quotes interchange-plus. Helcim publishes interchange plus 0.40% plus $0.08 for a card-present sale (checked 2026-08-25). That markup is not a total, because the interchange underneath it does not appear on the page. No effective rate can be built from a markup alone, and why interchange-plus pricing cannot be totaled sets out that limit in full. It also does not help if you hold a custom rate that appears on no public page.

Sources

How this article was made. Written by Kaz, an independent publisher. All figures come from the companies' own published documentation; each figure carries the date it was last checked. I have not used these products, and nothing here is a personal test result. The arithmetic is shown so you can recalculate with your own numbers. Found an error? Use the contact form; corrections are logged on the Editorial policy page.

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Written by Kaz (pen name). Figures are copied from providers' published pricing pages on the dates shown. We have not used these products. Corrections: contact form.