Card machines for smarter businesses

A card machine, also known as a credit card reader or PDQ machine, is a device that lets businesses accept card payments from customers in person. It connects to a payment processor, reads the customer's card or contactless payment via chip, tap, or swipe, and securely transmits the transaction for authorisation. Most modern card machines accept chip and PIN, contactless cards, and mobile wallets like Apple Pay and Google Pay. Once a payment is approved, funds are processed and settled into the business's nominated account, typically within one to two business days.

These terms are often used interchangeably, but there are some distinctions. A card reader usually refers to a smaller, more basic device that connects to a smartphone or tablet via Bluetooth to process payments. A card machine (or terminal) is typically a standalone device with its own screen, often supporting additional features like receipts, tipping, and point-of-sale functions. PDQ, which stands for "Process Data Quickly", is an older British term for the same category of device and is still commonly used, particularly by older or more established payment providers, though "card machine" and "terminal" are now more widely used.

Card machine costs vary greatly depending on the pricing model and provider. Some providers offer a pay-as-you-go model whereby you purchase the payment terminal upfront for a one-off cost and then pay a percentage transaction rate every time your customer pays. Alternatively, monthly hire contracts charge a recurring fee to rent the payment hardware, often with a customised transaction rate negotiated based on your turnover, but typically tied to a minimum contract term. Zeller follows the pay-as-you-go model, with no monthly fees and a flat 1.3% transaction fee on domestic Visa and Mastercard payments.

No. Zeller charges a flat 1.3% transaction fee on domestic Visa and Mastercard payments, 1.5% for manually entered transactions, and 1.99% for American Express — with zero monthly rental fees and zero PCI compliance fees. There are no setup fees, no lock-in contracts, and no hidden chargeback fees either.

Most card machines require Wi-Fi to process payments, but some modern machines, like Zeller Terminal, feature dual-connectivity, using an integrated, free 4G SIM card to process payments over cellular networks as well. This gives businesses flexibility to take payments without a fixed internet connection. Premium devices also support offline payments, allowing transactions to be processed and queued even when completely disconnected, syncing once a connection is restored.

Choosing the right card machine is one of the most consequential decisions a small business will make, with implications that extend well beyond the device itself. The right choice affects your cash flow, your day-to-day operational efficiency, and how much of your revenue you keep after fees.

Card machine vs card reader vs PDQ terminal: which do you need?

Not all card machines are built the same, and understanding the differences will help you choose the right device for how your business operates.

Card readers are the most compact and affordable option. They connect to a smartphone app via Bluetooth, rely entirely on your phone's screen and internet connection, and are ideal for very low-volume or occasional sellers, think market stalls or pop-up events. They typically can't operate independently of a paired phone.

Smart and portable card terminals, like Zeller Terminal, are standalone touchscreen devices that don't require a separate phone or app to operate. They connect via Wi-Fi or an integrated 4G SIM card, making them suited to businesses that move around: hospitality staff taking payment at the table, tradespeople on a job, or retailers who want the flexibility to walk the shop floor. Some, like Zeller Terminal 1x, include a built-in thermal receipt printer; others rely on digital receipts via email or SMS.

PDQ terminals (an older term standing for "Process Data Quickly") are typically wired, countertop devices built for fixed checkout points with consistently high transaction volumes, such as larger retail counters.

For most small and micro businesses, a smart portable card machine like Zeller Terminal offers the best balance: the reliability and features of a standalone device, without being tied to a single countertop location.

How much does a card machine cost?

Card machine pricing in the UK generally falls into two models, and understanding the difference is the single biggest factor in keeping costs under control.

Pay-as-you-go, where you buy the hardware outright (typically £19 to £199 + VAT depending on the device) and pay a per-transaction fee, usually ranging from around 0.8% to 1.75% for domestic cards, with no ongoing monthly cost.

Monthly hire, where you pay a recurring rental fee (typically £10 to £25 per month) in exchange for the hardware, often combined with a custom transaction rate negotiated based on your turnover. This model usually involves a longer-term contract.

Zeller follows the pay-as-you-go model: Zeller Terminal starts from £99 to purchase outright, with no monthly fees, no lock-in contracts, and a flat 1.3% transaction fee on domestic Visa and Mastercard payments (1.5% for transactions taken manually over the phone). For businesses that want to avoid long-term commitments, this is generally the more flexible option.

When comparing providers, look beyond the headline transaction rate. Some providers add monthly account fees, PCI compliance fees, chargeback fees, or minimum monthly transaction requirements that aren't obvious until after sign-up. The true cost of a card machine is the combination of hardware cost, transaction fees, and any recurring charges, not any single number in isolation.

Payout and settlement speed

How quickly funds reach your account can be just as important as the fee you're paying, particularly for cash-flow-sensitive businesses. Settlement speed varies significantly by provider, ranging from instant access (often tied to a provider's own business account) to two or more business days when settling to a third-party bank.

Zeller settles payments overnight into a free Zeller Transaction Account, or the next business day if you'd prefer to settle into a different bank account.

For businesses operating on tight margins, faster settlement isn't just a convenience; it directly affects your ability to pay suppliers, staff, and overheads on time, without relying on additional working capital or overdraft facilities.

Connectivity and offline payments

Some modern standalone card machines, like Zeller Terminal, offer dual connectivity, connecting via Wi-Fi or an integrated 4G SIM card so payments can still be processed if one connection drops. This is particularly useful for mobile or outdoor businesses without reliable Wi-Fi.

Some premium terminals also support an "offline mode", which allows transactions to be queued and processed once connectivity is restored, even if the device is fully disconnected. This feature isn't universal across providers, so it's worth checking with your provider directly if uninterrupted connectivity is a priority for your business. Zeller Terminal connects via Wi-Fi or 4G SIM but does not currently support offline payment processing, so an active connection is required to process transactions.

For most businesses operating in areas with reliable 4G or Wi-Fi coverage, dual connectivity alone is sufficient. Offline mode tends to matter most for businesses regularly trading in low-signal environments, such as rural markets or large event venues.

Integrating your card machine with other business software

A card machine increasingly needs to work as part of a wider business toolkit, not just as a standalone payment device. When choosing a provider, consider how well the terminal integrates with point-of-sale software, accounting tools like Xero, inventory management, and invoicing.

Zeller Terminal integrates natively with Zeller POS, at no extra cost, allowing businesses to build an item library, track sales, and manage stock across multiple sites.

If your business already relies on specific software for point of sale, stock management, or accounting, it's worth confirming integration compatibility before committing to a provider, since switching terminals later can mean re-establishing those connections from scratch.

Choosing the right card machine for your business

There's no single "best" card machine, only the device that best matches how your business operates. As a starting point:

• If you're an occasional or very low-volume seller, a basic Bluetooth-connected card reader paired with a smartphone app is likely the most cost-effective choice.

• If you run a small or growing business that needs reliability, mobility, and built-in features like POS, receipts, and tipping, a standalone card machine, like Zeller Terminal, is a good fit.

• If you operate from a fixed location with consistently high transaction volumes, a wired countertop PDQ machine, like Zeller Terminal, may offer the most stable, heavy-duty solution.

Whichever route you choose, weigh up the full picture: hardware cost, transaction fees, contract length, settlement speed, software integrations, and security compliance, rather than focusing on any single factor in isolation.