Square vs. iZettle vs. SumUp: compare UK’s 3 best card readers

It’s easier than ever to accept credit and debit cards. Forget the costly card machines of yore. Instead, check out these contactless card readers that process payments with a smartphone or tablet through easy-to-use, free point of sale (POS) apps.

In 2020, the race between the most popular mobile card readers in the UK is close. On our top three list, Square trumps PayPal Here as it simply offers more features at better rates. Cost-conscious start-ups often prefer SumUp’s lowest transaction fee, while iZettle and Square have the most superior free payment apps.

All three systems share characteristics that make them very attractive to small businesses. Setup costs are very low, and there are no fixed, monthly fees and no minimum transaction volume required. Plus: there’s no contractual commitment with any of these companies.

SumUp Air, iZettle Reader and Square Reader are therefore suitable both for infrequent use and for processing many transactions daily as your primary POS solution.

Cards, payouts and charges

As opposed to traditional card machines, you purchase the card readers for a low price with no future rental charges or lock-in to worry about.

iZettle currently accepts the most payment cards. On top of Visa, Mastercard and American Express accepted by all three, iZettle can handle Diners Club, JCB, Discover and UnionPay. SumUp also accepts Diners Club, Discover and UnionPay, but not JCB.

iZettle and Square charge a fixed percentage (1.75%) for all chip and contactless card transactions, but SumUp offers the lowest card rate at a fixed 1.69%, beating iZettle and Square by 0.06 percentage points. All of these fees apply to any credit and debit card, including foreign-issued and premium brands like Amex.

With SumUp, you are likely to get your funds after three working days. However, iZettle and Square will deposit funds in your bank account slightly faster – expect them to appear within one or two working days.

In addition, Square offers Instant Transfers, a voluntary setting that clears transactions in your bank account within 20 minutes at an additional cost of 1% per transaction.

Square gives you most options for keyed-in (i.e. remote) payments: a free virtual terminal, digital invoices, ecommerce and the ability to manually enter card details in the POS app. iZettle comes second with its email invoices, payment links and ecommerce, while SumUp can only maybe activate a virtual terminal upon request. All key-in payments have a higher transaction fee.

Apps and customer service

The Square and iZettle apps are ahead of the game, with more features than SumUp’s app. That said, SumUp is the only one with free customer support on Saturdays as well as working days – you can only phone Square and iZettle on weekdays.

All three card readers work with iPad, iPhone and Android tablets and phones. The product libraries in each app look modern with images and details so you can sell different sizes or types of each item. Square’s app, called Point of Sale, beats iZettle and SumUp with additional features like gift cards, split bills and optional employee permissions (costing extra).

It is possible to use any of the card readers with more complex POS software, so you are not limited to the free apps. iZettle and Square have their own fully integrated ecommerce platforms available at a monthly cost, but Square can also be used in conjunction with several other ecommerce partners.

For more information on these mobile card readers, read our comprehensive reviews of each: iZettle, Square and SumUp.