Most card readers sold in the UK depend on an internet connection to process payments. Some use your phone’s data via Bluetooth. Others need your business WiFi. A few have their own SIM card and don’t need either. If you have a reliable connection, these differences don’t matter. If you don’t, for example trading outdoors, visiting customer sites, working at events, or based in a building with poor signal, then it matters a lot. A reader that can’t connect can’t take payments, and that failure tends to happen at the worst possible moment.
This guide covers the options for businesses that can’t rely on WiFi or stable mobile data.
Why a good connection matters
Most card reader comparisons assume you’re running a shop with broadband. For a significant portion of small businesses, that assumption is wrong.
Market stalls, food vans, festival sellers, tradespeople, mobile beauticians, garden centres, farm shops, pop-up shops — all of these involve taking payments in environments where WiFi either doesn’t exist or is too unreliable to depend on.
The problem with Bluetooth card readers, which are the most popular and cheapest type, is that they don’t have their own internet connection. They pair with your phone and use your phone’s mobile data. On a crowded market with hundreds of people all streaming and hotspotting, that signal degrades. In a basement or rural location, it may not exist at all. The practical result is a failed payment at the worst possible moment.
Option 1: Standalone readers with built-in 4G SIM
The most reliable solution is a card reader with its own SIM card. These devices connect directly to mobile networks without depending on your phone’s data. Most roam across networks, finding signal independently rather than being tied to one carrier.
1. myPOS Go 2 — best value standalone 4G reader
Here’s something different – the myPOS Go 2 works completely independently without needing your smartphone. This standalone portable card reader has integrated 4G connectivity built right in, weighing just 180g and actually smaller than most modern smartphones. You’ll pay £29 excluding VAT upfront with zero monthly fees.Cost: £29 upfront, no monthly fee. Transaction fee: 1.1% + 7p. Settlement: Instant to built-in Visa account.
The myPOS Go 2 doesn’t need your phone for anything. Payments are processed through the device, receipts sent by SMS or email from the device, and money settled instantly into a built-in myPOS Visa account. It’s 180g and smaller than most smartphones. Battery handles a full day’s trading.
At £29 with no monthly fee, it’s the cheapest standalone 4G reader available in the UK and probably the most practical card reader for outdoor trading.
The fee structure (1.1% + 7p) is cheapest for mid-to-high-value transactions. Below roughly £10 per transaction, the 7p flat element makes it marginally more expensive than SumUp. For most market stalls, trades businesses, and mobile services, average transaction values are well above that threshold.
2. SumUp Solo – reliable standalone alternative
Cost: £79 + VAT upfront, no monthly fee. Transaction fee: 1.69% (or 0.99% on Payments Plus at £19/month). Settlement: Next day by 7am.
The SumUp Solo has its own SIM and WiFi. More expensive than myPOS upfront but with a cleaner percentage-only fee structure — no flat element per transaction, so costs are more predictable across varied transaction values.
Battery lasts around 10 hours. Settlement is next day rather than instant, which matters if cash flow is tight.
3. Dojo Go — best for businesses needing contracted rates
Cost: From ~£20–30/month rental, or £179 + VAT to buy outright. Transaction fee: From 1.4% + 5p. Contract: 12 months (rental).
Dojo is designed for hospitality and mobile businesses. Its hardware runs on 4G with strong network uptime and doesn’t need a phone or WiFi. The touchscreen is large, battery life is long, and tipping is handled natively.
The rental model comes with a 12-month contract. For businesses with consistent volume that want a proper terminal rather than a pocket-sized reader, Dojo’s combination of 4G independence and negotiated rates is worth considering.
4. Takepayments Plus — best standalone terminal with receipt printer
Cost: From ~£25/month, 12-month contract. Transaction fee: Tailored rates. Settlement: Next business day.
The Takepayments Plus runs on 4G and has a built-in receipt printer — the only mainstream portable terminal that doesn’t require a separate printer. The right choice for businesses that need to print receipts on the move: food traders with allergen labelling requirements, antiques dealers, mobile tradespeople.
Requires a 12-month contract and tailored pricing (a sales call rather than a website signup). Better suited to established businesses with consistent volume.
Option 2: Offline mode on phone-dependent readers
Several Bluetooth readers that normally pair with your phone can store transactions locally when the connection drops and process them once connectivity restores — sometimes called “store and forward.”
Square introduced automatic offline mode for all UK devices from April 2026. Transactions made offline are encrypted and stored on the device, then processed and cleared at the standard transaction fee when connectivity restores. One important caveat: tap-to-pay with physical cards doesn’t work in offline mode. Only digital wallets (Apple Pay, Google Pay) tap offline.
The risk with any offline mode: you won’t know if a card is declined until the connection is restored. If the card is fraudulent, stolen, or over its limit, the transaction will fail after the fact — by which point you’ve already completed the sale. For most businesses the risk is low, but worth knowing about for high-value transactions.
Offline mode is a contingency, not a strategy. If your location regularly has no signal, a standalone 4G reader is more reliable.
Option 3: MiFi devices
A MiFi device is a portable 4G router that creates its own WiFi hotspot. You connect your phone (and through it, your Bluetooth card reader) to the MiFi rather than the shared venue WiFi or your personal mobile data.
MiFi devices cost around £30–60 to buy outright. You need a data SIM, either a dedicated SIM-only plan (£5–15/month) or an additional SIM on an existing plan. The hotspot runs on its own data connection, completely separate from the congested public WiFi at a market or event venue.
This is the cheapest upgrade if you already use Square or SumUp and want better connectivity without replacing the hardware. At a trade fair or festival, running your reader through a dedicated MiFi rather than the venue’s overloaded network makes a real practical difference.
The limitation: if 4G coverage is genuinely absent — remote areas, thick-walled basements — a MiFi won’t help. In those cases, a standalone reader with a multi-network SIM that roams between carriers is more likely to find signal.
Option 4: Ethernet (fixed premises with unreliable WiFi)
For businesses in a fixed location where WiFi is unreliable — an old building, a basement, a retail unit with a poorly placed router — a countertop terminal connected via Ethernet is the most reliable fix.
Countertop terminals from Worldpay (Ingenico DX4000), Takepayments, and Barclaycard’s contracted range all support wired Ethernet connections. These come with contracts and monthly rentals, but for a permanent retail location the wired connection essentially eliminates connectivity problems.
Not relevant for mobile businesses, but worth knowing for fixed premises where WiFi performance is the actual problem.
Quick comparison
| Reader | Connection type | Needs phone? | Works without WiFi? | Offline mode? |
|---|---|---|---|---|
| myPOS Go 2 | Built-in 4G SIM | No | Yes | No (always connected) |
| SumUp Solo | Own SIM + WiFi | No | Yes (4G) | No |
| SumUp Solo Lite | Bluetooth to phone | Yes | Only via phone data | Yes (basic) |
| Square Reader 2 | Bluetooth to phone | Yes | Only via phone data | Yes (from Apr 2026) |
| Dojo Go | Built-in 4G | No | Yes | No |
| Barclaycard Smartpay | Bluetooth to phone | Yes | Only via phone data | No |
| Takepayments Plus | 4G + WiFi | No | Yes (4G) | No |
Our pick
For outdoor trading, events, or any location with unreliable signal: myPOS Go 2 (£29). Cheapest standalone 4G reader on the market, instant settlement, no monthly fee. The practical first choice for anyone whose livelihood depends on payments working in variable-signal environments.
For businesses already using Square or SumUp that need a connectivity upgrade: a MiFi device (~£30–60) is the cheaper fix before switching hardware.
For mobile businesses needing a full terminal with receipt printing: Takepayments Plus or Dojo Go, on a contract once volume justifies it.
See our best card readers for market traders, and our best card readers for small businesses for more detail on specific use cases.
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