Square and SumUp come up more often than any other names when a UK small business starts looking at card readers. Both are no-contract, both are pay-as-you-go, both cost under £100 to get started. The fee difference is small — 1.75% for Square, 1.69% for SumUp — and on most individual transactions you won’t notice it.
So why does the choice matter? Because under the surface they’re quite different products. SumUp does one thing well: cheap, simple card payments. Square does considerably more, and that’s either an asset or noise depending on what you need.
| Card Machine | Upfront/Device Cost | Monthly Fee | Transaction Fees | Contract Length | Key Features | Connectivity | Battery Life |
|---|---|---|---|---|---|---|---|
| Square Card Reader | £19 + VAT | None | 1.75% flat rate | No contract | Built-in receipt printer, offline mode, POS software included | WiFi & Ethernet | Full business day |
| SumUp Air | £34 + VAT | None | 1.69% (1.49% with Business Account) | No contract | OLED display, compact size | Bluetooth | 12 hours/500 transactions |
Fees
In-person transactions: SumUp charges 1.69%, Square charges 1.75%. On a £100 transaction, SumUp costs £1.69 and Square costs £1.75. Over a year of consistent trading it adds up, but it’s rarely the deciding factor.
Online and invoicing: SumUp charges 2.5% for payment links and invoices. Square charges 2.5% for invoices but 1.4% + 25p for payments through Square Online. If your average online order is above roughly £23, Square’s online rate is cheaper.
Subscription plans: both offer an optional monthly plan that drops the in-person rate. SumUp Payments Plus is £19/month and brings the rate to 0.99%. The crossover is around £3,300/month in card revenue — above that, the subscription pays for itself. Square’s paid plans start from £0 to £69/month and offer reduced rates plus additional software features.
Refunds: Square refunds its transaction fee when you issue a refund. SumUp doesn’t. On a £200 transaction that gets refunded, you’ve paid SumUp £3.38 and won’t see it again. If your business has frequent refunds — retail, events, deposits — that’s a real difference.
The net picture on fees: SumUp is marginally cheaper for in-person payments on the standard plan. Square is cheaper online above a low transaction threshold, and its refund policy is better. For a business that purely takes in-person payments and never issues refunds, SumUp saves a small amount. For most businesses with any online element, Square is more competitive. For more information, read our guide to card reader fees.
Hardware
SumUp’s 2026 range: the original Air has been replaced by the Solo Lite (£25 + VAT), a compact touchscreen reader that pairs with your phone via Bluetooth. The Solo (£79 + VAT) is a standalone terminal with its own SIM card — no phone required. SumUp also makes a Register (full EPOS terminal with printer) at the higher end.
Square’s 2026 range: the Square Reader 2 (£19 + VAT) is a small Bluetooth reader for your phone. The Square Terminal (£149 + VAT) is a standalone counter device with a large touchscreen and customer-facing display. The Square Register (£599 + VAT) is a full dual-screen POS system.
Build quality: the SumUp Solo Lite is compact and light, which is good for portability. Field reports note the plastic casing doesn’t survive rough handling particularly well — replacements take three to five business days. The Square Reader is smaller and similarly light; the Square Terminal is sturdier. Neither entry reader is rugged. If payments are your main income, a backup device (another Solo Lite at £25, or a second Square Reader at £19) is sensible insurance.
Warranty: Square gives you two years. SumUp gives you one.
The verdict on hardware: Square’s entry reader is cheaper (£19 vs £25), has a broader hardware range, a longer warranty, and the Terminal is a better counter device than anything SumUp offers at a similar price point.
Software and POS features
This is where the gap opens up.
Square’s free app includes a full item catalogue with images and variants, inventory tracking with stock alerts, staff accounts with individual permissions, detailed sales reports by item and staff member, tipping, loyalty programmes, gift cards, appointment booking (Square Appointments), and a free online store. For a small business that wants more than a payment app, it covers a lot of ground without a monthly fee.
SumUp’s app handles payments, a basic item library, team management (added in recent updates), and simple reports. It’s quick to learn and uncluttered. It doesn’t have the depth of Square for growing businesses — and it doesn’t try to.
The verdict on software: Square is materially more capable. For a business that wants EPOS features, online integration, staff tracking, or appointments, Square wins clearly. For a sole trader who wants to take payments with minimal fuss, SumUp’s simplicity is a feature, not a shortcoming.
Settlement
SumUp: next-day settlement by 7am, including weekends, to any UK bank account. No extra fee. Instant payout to a free SumUp business account at no charge.
Square: typically one to two business days to your bank. Instant transfer available for a 1.5% fee.
The verdict on settlement: SumUp’s next-day guarantee (including weekends) is better than Square’s standard settlement. If consistent fast access to funds matters — covering stock, paying suppliers — that’s worth noting.
Customer support
Both providers have had mixed reviews for support. SumUp’s Trustpilot score (4.1/5 from over 23,000 reviews) is solid, with praise for setup ease and hardware reliability. The consistent complaint is slow response from customer support, particularly for standard accounts on email or chat. Account holds during identity verification are the other recurring issue.
Square’s support is also variable. Paid plans include phone support; free accounts rely on chat and community forums.
Neither provider is known for outstanding support. Having a backup reader and a cash float is practical insurance regardless of who you choose.
Who should choose SumUp
SumUp is the better fit if you mainly take in-person payments and online sales aren’t a significant part of your business. If you want the simplest possible setup with minimal configuration. If you’re above £3,300/month in card revenue and the 0.99% Payments Plus rate is compelling. If you want guaranteed next-day settlement including weekends. If you’re a sole trader, market trader, or mobile worker who doesn’t need staff profiles or advanced reporting.
Who should choose Square
Square is the better fit if you take meaningful online sales alongside in-person payments — Square’s online rate is better above about £23 per transaction. If you want staff accounts, inventory tracking, or appointment booking on the free plan. If you issue refunds frequently and want the fee returned. If you’re likely to grow and want a platform that scales with you. If you want a two-year hardware warranty.
Quick comparison
| Square | SumUp | |
|---|---|---|
| Entry reader price | £19 + VAT | £25 + VAT (Solo Lite) |
| In-person rate | 1.75% | 1.69% |
| Online rate | 1.4% + 25p | 2.5% |
| Invoice rate | 2.5% | 2.5% |
| Subscription option | Yes (from £0/month) | Yes (£19/month, 0.99%) |
| Refunds fee back? | Yes | No |
| Standalone terminal | £149 (Terminal) | £79 (Solo) |
| Settlement | 1–2 days (instant for 1.5%) | Next day by 7am incl. weekends |
| POS software | Strong | Basic |
| Hardware warranty | 2 years | 1 year |
Our verdict
For most UK small businesses: Square. The slightly higher transaction rate is offset by better online pricing, fee refunds on returns, stronger software, and a longer warranty. If you’re building a business rather than just accepting the occasional payment, Square’s platform grows with you in a way SumUp’s doesn’t.
For sole traders and very simple businesses that purely need in-person payments: SumUp. Marginally cheaper on transactions, faster settlement, and less to configure. If you want to start taking cards today and not think about it again, SumUp gets out of your way.
See our guide to the best card readers for small businesses for the full comparison across all providers, or our guide to choosing a card reader if you’re still working out what you need.
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