Payment Processing · Buyer guide
When a customer in a UK shop pays with a UK personal debit card, the bank that issued the card can charge the shop's provider no more than 0.2% of the sale in interchange. On a UK personal credit card the cap is 0.3%. Both limits come from the EU Interchange Fee Regulation, which the UK kept on its statute book after Brexit and which still applies wherever the card issuer, the acquirer and the point of sale are all in the UK.
The shop does not pay 0.2%. It pays whatever its card machine provider charges, and on the providers this site has reviewed that runs from a representative 0.7% at Barclaycard to 1.75% at Square, before anyone has counted the machine, the monthly fee or the contract. The gap between the cap and the price is scheme fees, the provider's costs and the provider's margin, and it is the part a small business can actually shop on. Here is what each provider publishes, read from its own UK pages on 23 September 2026.
Take a café or shop taking £8,000 a month on cards, 400 transactions at an average of £20, all on UK personal cards tapped in person. On the published rates, before VAT on any monthly fee:
Barclaycard's 0.7% + 3p would come to £68 on the same volume if every card were personal debit, but it is an illustration of one card type rather than a price for a mixed till, and the machine is extra. Dojo and takepayments cannot be put on this basis at all.
Two things move this ranking more than the headline rate. The first is card mix. myPOS's rate more than doubles on a commercial card, and SumUp's Plus plan charges its pay-as-you-go rate on premium and Amex cards, so a business with a lot of company-card or rewards-card customers should price its own mix. The second is volume. SumUp's £19 plan saves 0.70 points on domestic cards, so on our arithmetic it pays for itself at about £2,700 a month of domestic card turnover. SumUp's own pages put the break-even at £3,000 on one page and £3,300 on another; the higher figure is roughly what you get if the £19 carries VAT.
The Payment Systems Regulator's card-acquiring market review, published in November 2021, found that the market did not work well for merchants with card turnover up to £50 million, and that merchants with card turnover between £15,000 and £50 million served by the five largest acquirers got "little or no pass-through" of the savings from the interchange cap. It identified three features that kept merchants from shopping around: prices that are not published, contracts that run on indefinitely, and card machine contracts that lock merchants in.
Its remedies have been in force since 2023. Directed providers must give merchants a summary box of their prices and an online quotation tool; must send a message 31 days before a minimum term ends, stating the date it ends, and monthly after that; and, for merchants with card turnover up to £10 million, must keep the initial term on a card terminal contract to 18 months, after which it becomes a rolling monthly contract with a month's notice. Exit fees on those contracts must be "cost-based, transparent and fully explained" before signing. The PSR's own factsheet notes that this does not stop an exit fee being charged within the 18 months.
The limits have edges. They cover countertop terminals, smart terminals and tills with a built-in card reader, but not a reader that pairs with your phone or tap-to-pay software on it. And the directions bind only the payment firms they name, among them Barclays, Square, SumUp, PayPal, Stripe, Worldpay, Lloyds and Global Payments' UK business. They reach a contract sold by a reseller or a leasing company when one of those firms does the acquiring behind it. Dojo, Teya, myPOS and Viva.com do not appear on the list. Whether a contract with one of them, or with a reseller such as takepayments, is covered depends on whose acquiring sits behind it, and that is a question to put to them in writing. The site's explainer on who actually holds your merchant agreement explains why a reseller's contract and the acquirer's can be two different documents.
The PSR's factsheet says the contracts it was replacing could lock a merchant in for as long as 48 months. That is still the typical length reported for a US terminal lease, which can outlive the processing contract it was sold with. With one of the directed firms behind it, a UK terminal contract's initial term now stops at 18 months.
The PSR itself is on its way out as a separate body. The government confirmed in April 2026 that it will fold the regulator into the Financial Conduct Authority, which needs primary legislation, and a bill to do it is before Parliament. The directions stay in force until someone changes them.
A US business can often add a card surcharge to recover its costs. A UK business cannot on most of its customers. Since 13 January 2018 UK law has banned surcharges on payments by any card that is not a commercial card. A business may add a fee on a company card, but only up to its actual cost of accepting it. For a consumer-facing shop, the card machine's price comes out of the margin, which makes the choice of provider the only lever there is.
Once you are trading, read your statement against what you were quoted. The site's guide to reading a merchant processing statement is written for US statements but the lines are the same: a rate, a set of fixed fees and a monthly charge, and the fixed fees are where quoted prices usually drift.
