Square's European rival iZettle is expanding to its second market in as many weeks.
Swedish company iZettle allows SMEs, hobby businesses and sole traders to take payments from customers using just a phone and an iZettle reader, doing away with the need for a chip and PIN card reader and merchant account with a bank.
On Wednesday, the company opened its doors for the first time in the UK, following a launch in the German market last week.
iZettle is making its UK entrance in partnership with EE, which will sell iZettle card readers in almost 300 of its stores. The readers are used in conjunction with the iZettle app for Android and iOS devices, and clip into phones or tablets through the audio jack.
The readers can accept payments from Visa, MasterCard, American Express and Diners Club cards (although not currently JCB), which customers verify by writing their signature on the device's touchscreen with their finger or a stylus. iZettle then processes the payment, and can email the customer a receipt for the purchase or create payment reports for the merchant.
Like competitor Square, iZettle takes 2.75 percent of each transaction for processing the payment. However, unlike its bigger rival, it does not currently offer a flat fee option.
iZettle has piloted its services in the UK for four months — a lengthy trial prompted by the UK's fondness for chip and PIN, rather than the chip and signature method iZettle uses, which is favoured in other European countries.
While iZettle tried PINs for the UK market, it found that customers were uncomfortable with entering their PIN numbers into other people's phones, and opted for the signature system instead.
Philippa Baker, who runs The Spitalfields Candle Company, was one of the guinea pigs. Baker, who had previously been unable to take card payments, first used the device at a recent fair in Olympia.
"We took £2,500 in six days," she said. "If you can't take card payments, then you can say 'I'll take a cheque or cash,' but often I would have lost about 40 percent of those sales."
The UK marks iZettle's sixth launch: the service has already gone live in Finland, Denmark, Norway, Germany, and its home market of Sweden.
More European expansion is also on the cards for the company. "There will be launches in more markets, either this year or next," iZettle's CEO Jacob de Geer told ZDNet.
Other developments are also being mulled: the company is considering whether to make a BlackBerry or Windows Phone version of its app, and expanding its range of offerings beyond simply taking payments, to analytics or loyalty tools.