What is a Card Machine?
A card machine is the single most important piece of kit for most UK businesses, and one of the least understood. What actually happens when a customer taps? Why do rates differ so much between providers? And what is the difference between a £19 card reader and a £30-a-month terminal? This guide answers all of it, in plain English, so you can choose and pay with confidence.
What is a card machine?
A card machine is a device that accepts debit and credit card payments in person, by contactless tap, chip and PIN, or mobile wallets like Apple Pay and Google Pay. It securely sends the card details to the banking system, gets an approval in around two seconds, and the money settles to your business account.
You will hear card machines called card payment machines, card terminals, PDQ machines or card readers. They all do the same core job; the differences are in form, features and how they are paid for. The older term PDQ has its own story, covered in what is a PDQ machine.
How does a card machine work?
When a customer taps or inserts their card, the machine encrypts the card details and sends them via your provider to the customer's bank, which approves or declines in seconds. The approved funds are then settled to your account, typically within one to three working days.
Behind that two-second tap sits a chain of players: the card scheme (Visa or Mastercard), the customer's bank, and your acquirer, each taking a small slice of the transaction. Understanding that chain is the key to understanding your fees, and it is mapped out fully in what is an acquirer and why are card machine fees so high.
What is the difference between a card reader and a card machine?
In everyday use, a card reader is the small, app-connected device from providers like SumUp and Square, bought outright from around £19 to £25, while a card machine usually means a full standalone terminal, typically rented from around £15 a month on a merchant account contract. Readers pair with flat-rate pricing; terminals pair with negotiated rates.
Neither is universally better. The reader route wins on simplicity and zero commitment; the terminal route wins on transaction rates and features once volume grows. There is also a third option now: phone-as-terminal apps that turn a standard smartphone into a contactless card machine with no hardware at all.
What types of card machine are there?
Four main types: countertop machines wired to a fixed point, portable machines that roam a premises on Wi-Fi, mobile machines that work anywhere on 4G, and app-based card readers or phone-as-terminal setups. The right one follows from where your customers pay.
| Type | How it connects | Best for |
|---|---|---|
| Countertop | Fixed, wired or Wi-Fi | Shops and counters with one till point |
| Portable | Wi-Fi around the premises | Restaurants, pubs, salons with table or chair service |
| Mobile | 4G and Wi-Fi | Trades, markets, taxis, anywhere without fixed premises |
| Card reader / phone-as-terminal | Pairs with a phone app | New, low-volume and occasional sellers |
Sector-specific picks are covered in our guides to the best card machine for small businesses and the best card machine for tradespeople and mobile businesses.
How much does a card machine cost?
There are two cost models. App-based readers cost £19 to £150 upfront with flat transaction fees around 1.69% to 1.75%. Contract terminals cost from around £15 a month in rental with negotiated rates from around 0.35% for debit and 0.65% for consumer credit, plus a standard PCI compliance fee of around £6 a month.
The crossover arrives around £3,000 to £5,000 a month in card takings: below it, flat-rate simplicity usually wins; above it, negotiated rates save real money because roughly 80% of UK consumer card payments are debit, the cheapest card type. The full working is in flat-rate vs custom pricing, and the standard monthly line items are decoded in how to read your card machine statement.
How do you get a card machine?
For an app-based reader, order the device and verify your details; most businesses take their first payment the same day. For a contract terminal, you apply through a provider for a merchant account, underwriting takes a few days, and the terminal arrives configured and ready.
Before signing any terminal contract, check the length (12 or 18 months is standard, and be wary of anything longer), the exit terms, and whether the hardware sits on a separate agreement, a known trap covered in merchant services contract traps. If you already have a machine and the deal has gone stale, switching provider is far less disruptive than most owners fear.
Do you need a card machine at all?
For face-to-face sales, almost certainly yes: cards dominate UK payments and cash-only costs sales. But if your customers pay remotely, a card machine may be the wrong tool entirely; payment links, QR codes and virtual terminals take card payments with no hardware.
Plenty of businesses run a hybrid: a machine for the counter, a QR code as backup and overflow, and a virtual terminal for phone deposits. Judge the setup on your true blended cost across all of it, not the headline rate on any single channel.
Choosing a card machine, or questioning the one you have?
Send us a recent statement, or just your expected monthly takings if you are starting out, and we will show you what a fair setup looks like for your volume. Free, no obligation.
Get your free statement reviewFrequently asked questions
How much is a card machine per month in the UK?
Contract terminals typically rent from around fifteen pounds a month, plus a PCI compliance fee of around six pounds and your transaction fees. App-based readers have no monthly cost at all; you buy the device outright and pay a flat rate per transaction.
Can I get a card machine without a contract?
Yes. Providers such as SumUp and Square sell card readers outright with no contract, no monthly fee and pay-as-you-go transaction rates. The trade-off is a flat rate around 1.69 to 1.75 percent, which becomes expensive as volume grows.
What fees do card machines charge?
The main cost is the transaction fee, either a flat rate around 1.69 to 1.75 percent or negotiated rates from around 0.35 percent for debit and 0.65 percent for consumer credit. Contract setups add terminal rental from around fifteen pounds and a PCI fee of around six pounds a month.
Do card machines need Wi-Fi?
Countertop and portable machines typically use Wi-Fi or a wired connection, while mobile machines include 4G so they work anywhere with signal. App-based readers use your phone's connection via Bluetooth pairing.
How long does money from a card machine take to reach my bank?
Typically one to three working days, with some providers offering next-day settlement as standard. Whether settlement is gross or net of fees changes how the amounts appear against your till records.
Can I use my phone as a card machine?
Yes. Tap-to-pay apps turn a standard NFC-enabled smartphone into a contactless card machine with no extra hardware, which suits very low-volume or occasional sellers. Dedicated devices remain better for busy counters and chip and PIN fallback.
What is the cheapest way to take card payments?
For low volume, an app-based reader with no monthly fee is cheapest overall. Above roughly three to five thousand pounds a month in card takings, a contract terminal with negotiated rates works out cheaper despite the monthly costs, because most UK payments are low-cost debit transactions.
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