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.
The race between the most popular mobile card readers in the UK is close. On our top three list, cost-conscious start-ups often prefer SumUp’s lowest transaction fee. Zettle’s card reader is simply the most loved while Square has the most superior free card reader app.
If that isn’t enough, all of these companies now offer standalone, portable touchscreen terminals that work without a phone.
Zettle Reader 2 | SumUp Air | Square Reader | |
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Solution | Card reader + smartphone/tablet app | ||
Price | £29 + VAT (offer) | £39 + VAT (offer) | £19 + VAT (offer) |
Transaction fee | 1.75% | 1.69% | 1.75% |
Contract lock-in | None | None | None |
Monthly fee | None | None | None |
Minimum sales volume | None | None | None |
Cards accepted | |
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Contactless | |||
Payouts | 1-3 working days | 1-3 working days | 0-2 working days |
PIN pad | On card reader | On card reader | In app on mobile screen |
Compatible receipt printers | Star Micronics, AirPrint | Star Micronics, Bixolon, AirPrint, Google Cloud Print | Star Micronics, Epson |
Digital receipts | |||
Staff accounts | |||
Product library | |||
Tipping | |||
Sales reports | CSV, Excel, PDF, Xero & QuickBooks integration | CSV, Excel, PDF, SumUp Accounting | CSV, Xero, Zoho Books & several other integrations |
Use abroad | |||
Zettle Reader |
SumUp Air |
Square Reader |
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Card reader + smartphone/tablet app | ||
£29 + VAT (offer) | £39 + VAT (offer) | £19 + VAT (offer) |
1.75% transaction fee | 1.69% transaction fee | 1.75% transaction fee |
No contract lock-in | ||
No monthly fees | ||
No minimum monthly sales volume required | ||
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Payouts 1-3 working days | Payouts 1-3 working days | Payouts 0-2 working days |
With physical PIN pad | With physical PIN pad | PIN pad in app on mobile screen |
Compatible receipt printers | ||
Star Micronics, AirPrint | Star Micronics, Bixolon, AirPrint, Google Cloud Print | Star Micronics, Epson |
Digital receipts | ||
Staff accounts | ||
Product library | ||
Tipping feature | ||
Sales reports | ||
CSV, Excel, PDF, Xero & QuickBooks integration | CSV, Excel, PDF, SumUp Accounting | CSV, Xero, Zoho Books & several other integrations |
Use abroad? | ||
The 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, Zettle and Square are therefore suitable both for infrequent use and processing many transactions daily as your primary POS solution.
Photo: SumUp

With SumUp Air and its app, you can accept almost any payment method.
Cards, payouts and charges
As opposed to a traditional card reader machine with a contract, you purchase the mobile card readers for a low price with no rental charges or lock-in.
Zettle currently accepts the most payment cards. On top of Visa, Mastercard and American Express accepted by all three, Zettle can handle Diners Club, JCB, Discover and UnionPay. SumUp also accepts Diners Club, Discover and UnionPay, but not JCB.
Zettle 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 Zettle and Square by 0.06 percentage points. All of these fees apply to any credit and debit cards, including foreign-issued and premium brands like Amex.
Card readers | From £29* | From £39* | From £19* |
Best deal | |||
Chip, tap payments | 1.75% | 1.69% | 1.75% |
Online store payments | n/a | 2.5% | 1.4% + 25p–2.5% + 25p |
QR code payments | 1.75% (via PayPal) | 2.5% | 1.4% + 25p–2.5% + 25p |
Payment links | 2.5% | 2.5% | 1.4% + 25p–2.5% + 25p |
Invoice transactions | 2.5% | 2.5% | 2.5% |
Keyed transactions | n/a | 2.95% + 25p | 2.5% |
Monthly fee | None | None | None |
Min. sales volume | None | None | None |
Settlement | Free | Free | Free, 1% for instant |
*Excluding VAT. Offers apply to the first card reader purchased.
Card readers from £29* (offer) | Card readers from £39* (offer) | Card readers from £19* (offer) |
Chip, tap payments | ||
1.75% | 1.69% | 1.75% |
Remote transaction fee | ||
Links, invoice: 2.5% QR code: 1.75% (via PayPal) |
Links, invoice, online store: 2.5% Virtual terminal, keyed: 2.95% + 25p |
Links, online store: European cards: 1.4% + 25p Intl. cards: 2.5% + 25p Virtual terminal, keyed, invoice: 2.5% |
Monthly fees | ||
None | None | None |
Minimum sales volume required | ||
None | None | None |
Payouts | ||
Free | Free | Free, 1% for instant |
*Excluding VAT. Offers apply to the first card reader purchased.
With SumUp, settlement takes up to three working days. Zettle and Square will deposit funds in your bank account slightly faster, 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. To compete, SumUp Business Account (with prepaid Mastercard) gives you access to transactions within 24 hours, even on weekends – and for free.
Point of sale features
All three card readers work with iPad, iPhone and Android tablets or phones, provided the associated payment app is downloaded and connected over Bluetooth.
The inventory libraries in each app look neat with images and product information so you can sell different sizes and types of each item. Square’s app, called Point of Sale, beats Zettle and SumUp with additional features like split bills, custom employee permissions (costing extra) and much more.
Photo: Square

Square has the best point of sale software connecting with its credit card reader.
Zettle’s POS features come at a close second, with physical gift card options, stock counts, barcode scanning via the phone camera, and more. The SumUp app has slightly fewer POS features, but more remote payment methods.
It is possible to use any of the card readers with more complex POS software so you are not limited to the free apps.
Square users can subscribe to Square for Retail, Square for Restaurants or Square Appointments for advanced till features, or a few excellent till systems like Vend and TouchBistro.
Zettle’s only upgrade is the Food & Drink app for small cafés, food trucks or similar, but Zettle Reader is compatible with many leading POS systems.
SumUp merchants can upgrade to SumUp Point of Sale, a user-friendly POS system where you can add modules of specialised features to suit any type of business.
What are the alternatives? See all app-based card readers in the UK
Standalone terminals available
If card readers for phones are not for you, Square, Zettle and SumUp offer card terminals that work independently. These have exactly the same transaction fees, no monthly costs and no contractual commitment.
One is Square Terminal, which has a touchscreen with POS features similar to the Square Point of Sale app. It works with secured WiFi connections only, so is best at a confined location, but can be carried around for table-service around your premises. It also has a built-in receipt printer.
SumUp Solo, on the other hand, doesn’t just work with WiFi – it also works with GPRS, EDGE and 3G through its inbuilt SIM card that comes with unlimited free data. It has very simple features – basically, it just accepts cards or mobile wallets and refunds payments. Alternatively, the standalone terminal SumUp 3G and Printer can print receipts too.
Zettle Terminal is a new entry that comes with the Zettle POS app built in and looks a lot like a smartphone. It works directly with WiFi, 3G or 4G (SIM card with unlimited data is included). It can be purchased on its own or with a receipt printer dock.
Photo: Zettle by PayPal

Zettle Terminal and Zettle Reader with the POS app.
Free online payment tools included
Square users get most options for keyed and online payments: a free virtual terminal for telephone payments, e-gift cards, digital invoices (with invoice app), online store builder, payment links, QR codes for touch-free payments, and the ability to manually enter card details in the POS app.
Remote payment | |||
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Payment link | |||
QR code | |||
E-gift card | |||
Email invoice | |||
Telephone payment | |||
Online store | |||
Click & collect |
Payment links | ||
QR codes | ||
E-gift cards | ||
Email invoices | ||
Telephone payments | ||
Online store | ||
Click & collect | ||
In second place, SumUp has complimentary payment links to share via QR code, social apps or text, digital gift cards, email invoices and a basic online store created through the app in a few simple steps. A basic virtual terminal can also be activated for most users, including manual card entry at the POS checkout.
Zettle only offers basic email invoicing, gift cards, payment links and QR code payments via PayPal, so remote payment options are a bit limited. You can nevertheless integrate the account with ecommerce platforms like Shopify and PrestaShop.
Many of these online payments were introduced as a response to the Covid-19 pandemic, and they are definitely handy for remote or socially distanced payments and online orders, but only Square and SumUp support a click-and-collect service.
They’re complete business solutions
Square, Zettle and SumUp are not just about card readers. Common to them all is their broad offering of integrated business tools connected to the same account, so you can get more done with less effort.
All of them have inventory management features for both retail and hospitality, the most advanced coming from Square.
Analytics and sales reports are included by all, with options to export data – or in the case of Square and Zettle, integrate with accounting software like Xero and QuickBooks. SumUp cannot integrate with accounting software, but is currently rolling out its own SumUp Accounting system to merchants.
Square is constantly expanding its own (paid or free) business tools, such as the new email marketing and customer loyalty features built into the platform. Users can also connect with lots of external software for things like ecommerce, marketing, food delivery and inventory management.
Zettle only connects with a few accounting systems and ecommerce builders. SumUp has a closed system relying on its own features instead of integrations.
No matter which platform you choose, you benefit from a lack of contract obligations, monthly fees or complicated terms. Instead, you get simple fees and a trusted payment system designed to help your business grow – it doesn’t get simpler than that.