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Square Reader vs. Zettle Card Reader 2 vs. SumUp Air ms payment logos

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Square Reader vs. Zettle Card Reader 2 vs. SumUp Air: Which Is Best For SMEs

SquareZettle and SumUp offer some of the most affordable entry-points into card payments for smaller businesses. 

Aside from their relatively high transaction fees, these brands also offer three of the cheapest card readers currently available on the market, allowing any business to accept card payments in-person.

In this article, we compare these three affordable card readers to help you decide which of them is most suitable for your business.



What Credit/Debit Cards Square, Zettle & SumUp Accept? 

Visa dominates the UK payment card scene with an 82% market share, but merchants need the flexibility to accept payments from every customer – whatever their preferred payment options may be. 

This is increasingly important as the adoption of mobile payments increases in the UK and international travel plays a key role in hospitality, retail and other sectors.

Here’s a quick overview of all the cards you can accept with the Zettle, SumUp and Square card readers.

  Square Zettle 2 SumUp Air
American Express ✔ ✔ ✔
Mastercard ✔ ✔ ✔
Maestro ✔ ✔ ✔
Visa ✔ ✔ ✔
Visa Election ✔ ✔ ✔
JCB ✖ ✔ ✖
UnionPay ✖ ✔ ✔
Discover ✖ ✔ ✔
Diners Club ✖ ✔ ✔
V Pay ✔ ✔ ✔
Apple Pay ✔ ✔ ✔
Google Pay ✔ ✔ ✔
Samsung Pay ✔ ✔ ✖

You can order any of these card readers online from the following links:

How big are the card readers?

While all three card readers are portable, there’s a big difference in the dimensions and weight of each device.

  Square Zettle 2 Sum Up Air
Size 66 x 66 x 10 mm 134 x 133 x 34 mm 84 x 84 x 23 mm
Weight 56g 220g 142g

The Square card reader is by far the smallest and lightest device among the three and you’ll struggle to find a more compact card reader on the market. Such design comes at the expense of having no keypad but you can use the mobile app on supported smartphones to provide a keypad for typing in PIN numbers and card details.

By comparison, the Zettle card reader is significantly larger and heavier but it’s still a compact device and the most robust of the bunch.

Is there any difference in connectivity? 

  Square Zettle 2 Sum Up Air
Wireless ✔ ✔ X
Bluetooth ✔ ✔ ✔
Contactless ✔ ✔ ✔

The SumUp card reader we’re looking at in this article (SumUp Air) only supports Bluetooth connectivity – so keep this in mind. The more expensive SumUp Solo card reader supports WiFi connectivity but costs £119. You can get a more comprehensive review of the SumUp card readers and prices here.

Are they all compatible with iOS and Android? 

Each of these card readers works with most devices using the latest versions of iOS and Android and they all support older versions of the software to varying degrees.

  Square Zettle 2 Sum Up Air
iOS N/A iOS 12 + iOS 10+
Android Android 4.4 + Android 5 + Android 4.4 +

Square doesn’t specify a minimum iOS version for its card reader but it does list the iPhone 4s as compatible and the latest version available on that model is iOS 9

How long does the battery last on each card reader?

  Square Zettle 2 Sum Up Air
Full charge ~100 transactions ~100 transactions ~500 transactions
USB charging cable Included Included Included
Charging dock £25 £39 £10*

At the time of writing, you can buy the SumUp Air card reader and charging dock bundle for £39 while the card reader only costs £29. Currently, SumUp doesn’t sell the charging dock separately but you can find them on Amazon and some other retailer websites.


How long will it take to get set up? 

Delivery is free with estimated shipping times of 2-3 business days but we’ve generally had our devices within 1-2 working days. When your device arrives, charge it up until full and connect your card reader to the mobile device you’re using to run the included POS software.

It should only take a few minutes to set up your card reader and, assuming your account with Square, Zettle or SumUp is active, you can start accepting card payments right away.

Which card machine is easiest to use?

Usability is always a compromise with devices like this and personal needs/preferences tend to dictate the experience of using them.

If you want the most portable card reader, then Square is the obvious choice but it’s also the easiest to misplace. The Zettle card reader is the bulkiest. The physical keypad makes typing PIN numbers and card details more intuitive.

Which is card reader is best for security and customer support? 

  Square Zettle 2 Sum Up Air
Tamperproof design ✔ ✔ ✔
Data encryption ✔ ✔ ✔
PCI compliance ✔ ✔ ✔
24/7 support ✖ ✖ ✖
Weekend support ✖ ✖ ✔
Online documentation ✔ ✔ ✔
Phone support ✔ ✔ ✔
Email support ✔ ✔ ✔

Square, Zettle and SumUp basically offer the same security features in these card readers, including PCI compliance across the board. The companies offer similar customer support options with email support and online documentation, but SumUp is the only one offering phone support over the weekends.

Square and Zettle’s phone support lines are open 9am to 5pm on weekdays only, while SumUp’s team is available from 8 am to 7 pm on weekdays and 8 am to 5 pm on Saturdays.

Which is the cheapest card reader?

  Square Zettle 2 Sum Up Air
Card reader £16 £29 £29
Transaction fees 1.75% 1.75% 1.69%
Charging dock £25 £39 £10*

All prices above exclude VAT

The cheapest card reader at present is the Square card reader. You can get a more in depth review of the Square card reader and fees here.

SumUp also offers lower transaction fees for in-person credit and debit card payments (other fees vary so make sure you compare the small print).

What Businesses Are These Card Readers Suitable For?

Square Reader vs. Zettle Card Reader 2 vs. SumUp Air Sqaure Card Reader
Square Card Reader

These card readers are designed for micro and small businesses that need one card reader connected to a phone or tablet.

Restaurants or slightly larger businesses may set up several payment points with card readers but you’ll start to get cheaper transaction fees elsewhere if you’re processing a high volume of card payments every month.

If you run a mobile business or offer services at customers’ locations (food truck, roofer, etc.) and you want a portable card reader that connects to your phone, Square is the ideal choice.

For on-premise businesses that want a simple POS system and card reader for accepting card payments, these are the three best options on the market.

What Other Card Reader Options Do Square, Zettle and SumUp Offer?

If you need a more advanced POS system, Square, Zettle and SumUp all offer higher-end card readers, software and accessories – including stands, printers and registers.

SumUp sticks to providing card readers and software for different business purposes but Square and Zettle both offer complete till systems with touchscreen displays, stands and accessories (printers, scanners, etc). 

Final Verdict

Square, Zettle and SumUp are the top three providers of affordable card readers for micro and small businesses and on balance we think Square is probably the best option for most small businesses.

It all comes down to what type and size of business you are running. If you’re still unsure which option to choose or you feel neither of them is suitable, fill out this form to get our personalised quotes and the best rates from each provider.

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