Most card reader guides are optimised for volume. The more transactions you process, the more a lower per-transaction rate matters, and the more a monthly subscription starts to make sense. Sole traders and freelancers often don’t work that way.
You might take card payments every day for three weeks and then barely at all for a month. You probably don’t want a subscription running in the background during the quiet periods. You need something that works from your phone, in different locations, without a fixed setup.
The reader that suits a cafe processing 200 transactions a day isn’t the same one that suits a mobile beautician, a personal trainer, or a self-employed plumber collecting payment at the end of a job. That’s what this is about.
Quick answer: For most sole traders, Square Reader (£19 + VAT, 1.75%, no monthly fee) is the sensible starting point. If you also take remote payments by sending clients a link, SumUp Air (£39 + VAT, 1.69%) handles that more cleanly. Both work the same day, no application required.
Features and fees that matter
Fee structure is the first thing. Specifically: no monthly fee, because your volume fluctuates. A reader with a lower transaction rate but a £25/month subscription only saves you money if your card sales are high and predictable every month. For most sole traders, they aren’t.
Beyond that, a few things come up regularly.
Payment links: Some readers let you send a client a link by text or email, they click and pay by card online, and you don’t need to be there. This is useful if you invoice clients ahead of time, collect deposits remotely, or work with clients who pay after the fact.
Settlement speed: When a client pays a deposit before you start a job, you sometimes need to know it’s cleared. Most readers take one to three working days. A couple are faster.
Simplicity: You don’t need staff management, multi-location reporting, or an inventory system for 800 SKUs. You need to take a payment, send a receipt, and get on with the job.
Square Card Reader
£19 + VAT | 1.75% | No monthly fee
The sensible default for sole traders who aren’t sure how much they’ll use it. Nineteen pounds is low enough that buying it on a maybe makes sense — if your clients end up preferring bank transfer, you haven’t lost much.
There’s no application process. Download the app, pair the reader, take a payment. The whole setup takes ten minutes if you’re slow about it.
The fee is flat — 1.75% on everything, nothing else. No floor charge, no minimum transaction, no different rate for Saturdays. On a £50 payment, 87.5p. On a £200 payment, £3.50.
The no-monthly-fee model works well when income is uneven. January being slow doesn’t cost you anything beyond the transactions you actually take.
Square has a payment link feature — you generate a link in the app and send it to a client to pay online. It works, though the setup is slightly less slick than SumUp’s equivalent.
Settlement is one to two working days into whatever bank account you provide. No minimum balance required, no need for a business account.
SumUp Air
£39 + VAT | 1.69% | No monthly fee
The rate is 0.06% lower than Square. At £1,000/month, that saves about £7.20/year — not the reason to choose it.
The reason to choose SumUp over Square is the payment link setup. You can send a link by text, WhatsApp, or email, and the client pays online at the same 1.69% rate. For freelancers who do a lot of remote invoicing — designers, consultants, photographers — that’s cleaner than Square’s equivalent.
SumUp also connects natively to Xero, which matters if you use Xero for your accounts. Transactions import cleanly without having to reformat a CSV.
At £39 upfront, the extra £20 over Square takes a while to pay off at typical sole trader volumes. The break-even in running costs is around 16 months at £1,000/month. Whether it’s worth it sooner depends on how often you actually use the payment link feature.
Zettle Reader 2
£29 + VAT | 1.75% | No monthly fee
Same rate as Square, £10 more for the hardware. On pure numbers, Square is cheaper. The reason to pick Zettle is if you already take online payments through PayPal — having in-person and online transactions show up in the same account makes reconciliation easier.
The reader itself is well built and the app is reliable. For a sole trader who doesn’t use PayPal, there’s no particular reason to pay the extra £10 for it.
myPOS Go 2
£29 + VAT | 1.75% + 2p per transaction | No monthly fee
The thing that’s different about myPOS is it doesn’t need your phone. It has its own SIM and its own screen. If you’re fitting kitchens, doing vehicle repairs, or working in any situation where having your phone out is impractical, that matters.
Payments settle into a myPOS account within seconds. The money isn’t in your main bank account — you still need to transfer it out, which takes another day or two — but it’s confirmed and visible immediately. For a sole trader who needs to know a deposit has cleared before starting a job, that confirmation is useful even if the actual funds aren’t instant.
The 2p flat charge per transaction adds a small amount to every payment on top of the percentage. On a £10 payment, Square takes 17.5p, myPOS takes 19.5p. It won’t change your decision, but it’s there.
Revolut Reader
£49 + VAT | 0.8% + 2p on Grow plan (£25/month) | 1.75% on the free plan
The 0.8% rate is the lowest available without a fixed contract. The catch is it requires the Grow plan at £25/month.
The breakeven against Square: £25 divided by (1.75% minus 0.8%) = roughly £2,630/month in card sales. Most sole traders and freelancers don’t hit that consistently. At £1,000/month, Revolut Grow costs around £334 in year one (hardware + plan + fees). Square costs £139. The maths doesn’t work at low volume.
Revolut only makes sense for sole traders who process significant, predictable card volume — and who are already using Revolut Business for banking, so the integration has independent value.
On the free plan, the rate matches Square but the hardware costs £30 more. There’s no good reason to buy it on the free plan.
What each option costs at typical sole trader volumes
At £500/month in card sales:
| Reader | Hardware | Annual fees | Year one total |
| Square | £19 | £105 | £124 |
| Zettle | £29 | £105 | £134 |
| myPOS Go 2 | £29 | ~£108 | ~£137 |
| SumUp Air | £39 | £101 | £140 |
| Revolut (Grow) | £49 | £348 | £397 |
At £2,000/month in card sales:
| Reader | Hardware | Annual fees | Year one total |
| Square | £19 | £420 | £439 |
| SumUp Air | £39 | £406 | £445 |
| Zettle | £29 | £420 | £449 |
| myPOS Go 2 | £29 | ~£432 | ~£461 |
| Revolut (Grow) | £49 | £492 | £541 |
Revolut Grow doesn’t become cheaper than Square until monthly card sales consistently exceed £2,630. Most sole traders won’t reach that.
Also worth knowing
You don’t need a business bank account. Square, SumUp, and Zettle settle into any UK account. If you haven’t opened a business account yet, that’s not holding you back.
Refunds don’t return your transaction fee. If you refund a client, the 1.75% (or whatever rate you’re on) stays with the provider. On a £200 refund, that’s £3.50 gone. If you take deposits that sometimes get refunded, it’s worth factoring in.
Chargebacks happen occasionally. A client disputes a payment with their bank, the money is pulled from your account while it’s investigated. Square charges £15 per dispute. SumUp doesn’t charge a fee. Keeping records of what was agreed — a message, an email, a signed quote — is your main protection.
Most readers accept Amex. Square charges the same 1.75% for Amex in-person payments. If your clients are business owners who pay on company cards, you can take them.
Frequently asked questions
No. Sole traders sign up with personal details — name, address, bank account. No company registration or business bank account required.
Yes. Square and SumUp both let you apply VAT and generate a VAT receipt. If you’re not VAT registered, you can still issue a standard receipt.
Yes, as two separate transactions. There’s no built-in deposit system, but processing them separately works fine.
The payment won’t complete. If battery is a real concern in your line of work, either carry a portable charger or look at a reader with its own screen: SumUp Solo (£99 + VAT) or myPOS Go 2 both work without a phone.
No minimum for Square, SumUp, or Zettle. The maths works on small amounts, though taking a card payment for 50p is probably not worth anyone’s time.
For a broader comparison covering more reader types, total cost at higher volumes, and what suits different business setups, see our full guide to the best card readers for small businesses in the UK.
