If you’ve just started taking card payments, or you’re comparing what you’re currently paying against other options, the fee structure can look more confusing than it actually is. There are only a few things you really need to understand.
The short version: Most UK card readers charge between 1.69% and 1.75% per transaction with no monthly fee. On £3,000/month in card sales, that’s around £51–£53 per month in fees. A monthly plan can cut that, but only makes sense once your volume is predictable enough that the fixed cost is worth committing to.
Two types of cost
Transaction fees are charged as a percentage of every payment you take, sometimes with a small flat charge on top. The provider deducts this automatically; you never send a separate payment. You just receive a little less per transaction than the customer paid.
Monthly plan fees are a fixed subscription charge, regardless of volume. Some providers offer a lower transaction rate in exchange for this. Others don’t have a monthly option at all, you just pay per transaction.
The choice between them comes down to one question: how consistently busy are you?
Pay-as-you-go
No monthly fee. You pay a percentage on every transaction.
Square charges 1.75%. SumUp charges 1.69%. Zettle charges 1.75%. These are flat rates — the same whether it’s a debit card, a credit card, or a Sunday in December. If you process nothing, you pay nothing.
This model suits most small businesses, and almost all sole traders and freelancers. Your costs scale with your revenue. January being slow doesn’t add anything to your overheads. And you’re not locked into anything if you switch providers or stop taking card payments.
The trade-off is that the rate is higher than it needs to be at significant volume. At 1.75%, every £10,000 processed costs £175 in fees. Once you’re consistently taking that kind of money by card, a monthly plan starts to look worth running the numbers on.
Monthly plans
A monthly subscription in exchange for a lower per-transaction rate.
The clearest example is Revolut’s Grow plan: £25/month for a rate of 0.8% + 2p per transaction. That’s less than half of Square’s pay-as-you-go rate.
The breakeven against Square:
£25 ÷ (1.75% − 0.8%) = roughly £2,630/month in card sales
Below that, Square is cheaper. Above it, Revolut Grow saves money. At £5,000/month, you’d save around £20/month. At £8,000/month, closer to £55/month. Over a year that’s real money — but it’s only worth having if you can reliably hit that volume, not just in good months.
Fees at different volumes
These figures use standard pay-as-you-go rates. The myPOS figures assume roughly 100–300 transactions depending on volume, since they also charge 2p per transaction flat.
At £1,000/month in card sales:
| Provider | Monthly fee cost |
| SumUp (1.69%) | £16.90 |
| Square (1.75%) | £17.50 |
| Zettle (1.75%) | £17.50 |
| myPOS Go 2 (1.75% + 2p/txn) | ~£19.50 |
| Revolut Grow (0.8% + £25/month) | ~£33 |
At £3,000/month:
| Provider | Monthly fee cost |
| SumUp | £50.70 |
| Square | £52.50 |
| Zettle | £52.50 |
| Revolut Grow | ~£49 |
| myPOS Go 2 | ~£56 |
At £3,000/month, Revolut Grow is fractionally cheaper than Square — but only just, and only after the £25 plan fee. That gap widens as volume increases.
At £6,000/month:
| Provider | Monthly fee cost |
| Revolut Grow | ~£73 |
| SumUp | £101.40 |
| Square | £105 |
| Zettle | £105 |
By £6,000/month, Revolut Grow is saving roughly £30/month over the pay-as-you-go options. Worth switching for, if your volume is there.
The costs that aren’t in the headline rate
Chargebacks. When a customer disputes a payment with their bank, the amount is pulled back from your account while it’s investigated. Square charges £15 per dispute. SumUp doesn’t charge a fee. That difference is easy to overlook when comparing rates, but it adds up if you ever have to deal with a difficult transaction.
Refunds. If you refund a customer, you don’t get the original fee back. The percentage stays with the provider. On a £200 refund at 1.75%, that’s £3.50 permanently gone. If you take deposits or have a returns policy of any kind, this accumulates.
International cards. Some providers charge more for cards issued outside the UK. Square charges 2.5% for non-UK billing addresses. If any of your customers are overseas visitors or international business clients, this is worth knowing before you pick a provider.
American Express. Amex sets its own (higher) interchange rates, and most providers either don’t accept Amex or charge extra for it. Square takes Amex at the standard 1.75% in-person rate, which is unusual. Worth knowing if you serve businesses whose staff travel and pay on company Amex.
What about interchange?
Every card payment involves the customer’s bank (the issuing bank) charging a fee to the business’s bank (the acquiring bank). That’s interchange, and it’s set by Visa and Mastercard.
The rates vary by card type. Personal debit cards are capped at 0.2% under UK regulation. Personal credit cards are capped at 0.3%. Business credit cards typically run 1.5–2.5%. Amex sets its own rate, typically 2–3%.
Most card reader providers bundle interchange into a single flat rate. That’s simpler for planning, but it means you pay the same 1.75% whether a customer taps a basic debit card (where the actual interchange cost is 0.2%) or a premium business credit card (where it’s much higher). You overpay on cheap transactions and underpay on expensive ones, relative to actual cost. For most small businesses, the predictability is worth the rough averaging.
When do I receive the money?
Square and Revolut (for Revolut Business customers) settle next working day. SumUp and Zettle take one to three working days. myPOS settles into its own account within seconds, but you then need to transfer it out, adding another day or two.
For most businesses, the settlement timing is irrelevant. It starts to matter when you’re taking a deposit before beginning work and need to confirm it’s cleared.
A few other things worth knowing
Surcharging is illegal in the UK. You cannot add a card fee to a customer’s bill: it was banned in January 2018 under the Payment Services Regulations. You can offer a cash discount if you want to encourage non-card payments, but you can’t add a surcharge for paying by card.
Transaction fees are VAT-exempt. Financial services fees in the UK are outside the scope of VAT. You won’t reclaim VAT on your transaction fees because there’s none charged. The reader hardware itself does include VAT.
Card-present vs card-not-present matters. The published rates of 1.75%, 1.69%, etc. apply to in-person transactions where the card is physically tapped or inserted. Payments taken over the phone or through a website are “card-not-present” and typically attract higher rates. Check the small print if you take phone orders.
Frequently asked questions
Not automatically. You stay on the published rate unless you move to a monthly plan or negotiate a custom rate directly with the provider. Square and SumUp both offer custom pricing for businesses processing significant volume — typically upwards of £10,000–£15,000/month.
Card readers are for one-off, in-person transactions. Recurring billing — memberships, subscriptions, regular client invoices — requires a different product. GoCardless (direct debit) and Stripe (recurring card charges) are the usual options for UK businesses. Different fee model, different setup.
Technically yes with some providers, but practically it varies. Square lets you set up multiple locations within one account, each with a different name and address. SumUp doesn’t have a native multi-business feature. Worth checking with your chosen provider before assuming it works.
No legal minimum in the UK, and none set by Square, SumUp, or Zettle. Technically you could process a 10p transaction. In practice, the maths work fine for any amount above a pound or so — it’s more a question of whether it’s worth the time.
For a side-by-side comparison of which card reader works best at your trading volume and business type, see our guide to the best card readers for small businesses in the UK.
