Flatpay vs Square: UK Comparison 2026

On paper, Flatpay and Square look like they compete in the same space: both offer payment terminals, both target small businesses, and both position themselves as transparent alternatives to traditional merchant services. In practice, they are quite different platforms built for quite different types of merchant.

Flatpay is a pure in-person payment specialist. One product category, one flat rate, one defining service feature — a specialist who installs everything at your premises. Square is a full commerce ecosystem: card readers, POS software, online stores, appointment booking, team management, loyalty programmes, and business loans.

This comparison uses data sourced directly from both providers’ UK websites in August 2026.

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Flatpay vs Square: At a Glance

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About Flatpay

Flatpay was founded in 2022 in Copenhagen, Denmark, by Peter Lüth, Sander Janca-Jensen, and Rasmus Busk. Backed by Seed Capital, Dawn Capital, AVP, and Smash Capital, Flatpay has grown to over 70,000 merchants across six European markets, with its UK office in London’s White City.

Flatpay ApS is registered at Companies House as a UK establishment (BR027644) but does not appear to hold FCA authorisation. Merchants who need regulatory certainty should check register.fca.org.uk before signing up. Flatpay does not offer business bank accounts, invoicing, payment links, online stores, or booking systems.

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About Square

Square was founded in 2009 in San Francisco by Jack Dorsey and Jim McKelvey and is owned by Block, Inc. (NYSE: SQ). In the UK it operates through Squareup Europe Ltd, registered in England and Wales (company number 08957689) and FCA authorised under the Electronic Money Regulations 2011 (FRN 900846).

Square’s product suite extends far beyond card processing: dedicated POS systems for restaurants, retail, and appointments; an online store; invoicing; virtual terminals; Clearpay BNPL integration; loyalty programmes; marketing tools; team management; and a full developer API. Square Loans — the business lending product — is explicitly not FCA regulated, as stated on Square’s own UK website.

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Fees: The Full Picture

The headline rate comparison is straightforward: Flatpay’s Terminal charges 1.49% per in-person transaction, Square charges 1.75%. But there is more to understand than the headline numbers.

Key Differences to Understand

Flatpay charges the same rate for every card type, including AMEX and non-domestic cards. Square charges an additional 1.5% surcharge on top of its standard rate for cards issued outside the UK — a real cost for businesses serving international tourists or corporate clients with foreign-issued cards.

Square keeps the processing fee when a merchant issues a refund. Flatpay does not publish a refund policy on its UK website — confirm this directly before signing up if your business has high return rates.

Square charges £0 for chargebacks. Flatpay does not publish a chargeback fee. Square’s £0 chargeback policy is a commercially meaningful advantage for any business in sectors prone to disputes.

Square’s online payment rate of 1.4% + 25p for UK cards does not apply to Flatpay, which has no online payment product.

Always confirm current pricing before signing up.

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Hardware: What You Get

Flatpay’s Hardware Approach

Flatpay’s entire hardware range is built around the PAX A920 Pro — an Android terminal with NFC, WiFi, and 4G connectivity, a built-in SIM card, and a fast integrated receipt printer. The Terminal carries no setup fee. Moving up to the mPOS, POS Pro, or POS Premium requires one-off onboarding fees of £995, £1,495, or £2,495 respectively, covering hardware, installation, configuration, and training. Flatpay does not publish warranty or returns terms on its UK website — confirm before purchasing.

Square’s Hardware Approach

Square’s hardware range is broader and more accessible. The Reader starts at £19 plus VAT. The Terminal at £149 is standalone with a built-in printer. The Register at £699 is a dual-screen countertop POS. All hardware carries a 2-year limited warranty and free 30-day returns. Interest-free instalment plans are available from 3 to 12 months on purchases of £29 to £3,000. Tap to Pay is free on any compatible iPhone or Android phone — no hardware needed at all to get started.

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Software & Features

Flatpay’s Software

Flatpay’s software covers payment processing and basic POS operations: sales, refunds, Z-reports, X-reports, and transaction history. The mPOS and POS products add table management, Dine-in/Dine-out mode, discounts, split billing, and optional kitchen printing. All merchants access the Merchant Portal for real-time reporting and automatic accounting uploads. Flatpay has no invoicing, payment links, online store, loyalty programme, gift cards, or appointment booking system.

Square’s Software

Square’s software breadth is its defining advantage. Square for Restaurants handles table management, kitchen displays, course routing, and online ordering. Square for Retail covers advanced inventory, multi-location selling, and barcode scanning. Square Appointments handles online booking, SMS reminders, and waitlists. Beyond vertical POS, Square offers free invoicing, free payment links, a virtual terminal, an online store, loyalty programmes, gift cards, email marketing, team management, and a full developer API with hundreds of App Marketplace integrations.

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Security & Regulation

Square: Strong Regulatory Transparency

Squareup Europe Ltd is FCA authorised (FRN 900846) under the Electronic Money Regulations 2011. Payments are end-to-end encrypted. Active fraud prevention is built into the platform. Chargebacks cost merchants £0 — a meaningful advantage compared to providers that charge up to £25 per dispute. The 2-year hardware warranty applies to all devices. The one important exception: Square Loans is not FCA regulated, as stated by Square on its own website.

Flatpay: Regulatory Position

Flatpay ApS is a Danish company registered at Companies House as a UK branch (BR027644). It does not appear to hold FCA authorisation. All card processing requires PCI DSS compliance and transaction encryption as standard — these are mandatory requirements for any business accepting card payments through Visa and Mastercard networks, and Flatpay’s processing will meet them. However, businesses in regulated sectors or any merchant for whom FCA authorisation matters should verify Flatpay’s status at register.fca.org.uk before committing.

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Business Funding

Flatpay Capital

Flatpay Capital is a merchant cash advance for existing Flatpay merchants, provided by Flatpay Financial Services A/S and powered by Liberis. Offers are pre-approved based on card sales history. Repayment is a daily percentage of card sales. Flatpay states 60% of merchants received funding within 3 business days in September 2025. All applications subject to underwriting. A minimum monthly repayment applies.

Square Loans

Square Loans is an invite-only business loan for eligible existing Square merchants. A typical offer: £10,000 with a flat fee of £1,325 (representative APR 18.90%). Repayment is 17.25% of daily Square card sales. Maximum term 18 months. No credit checks, no interest, no late fees. Explicitly not FCA regulated, as stated by Square. Eligibility limited to company or corporation structures — sole traders may not qualify.

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Best For: Side-by-Side

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Who Should Choose Flatpay?

Flatpay is the right choice for businesses that:

• Take almost all payments in person and need a simple, transparent flat rate — 1.49% Terminal beats Square’s 1.75%
• Want full hardware setup and staff training done by a specialist at their premises
• Run a hospitality business needing table management, Dine-in/Dine-out, and kitchen printing without a monthly subscription
• Don’t need online selling, invoicing, appointment booking, or loyalty tools

Flatpay may not suit:

• Businesses that also sell online — Square’s 1.4% + 25p for UK cards is significantly cheaper
• New or low-volume merchants needing the cheapest starting point — Tap to Pay or Square Reader are both cheaper to start
• Businesses that need confirmed FCA authorisation from their payment provider

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Who Should Choose Square?

Square is the right choice for businesses that:

• Need a complete commerce platform — payments, online store, invoicing, appointments, and team management from one provider
• Are just starting out and want the lowest cost of entry — Tap to Pay costs £0 in hardware, Reader costs £19
• Run a restaurant, retail store, or appointment-based business wanting dedicated vertical software
• Value £0 chargeback fees and clear FCA regulation
• Want interest-free hardware instalment plans
• May need developer API access or third-party integrations

Square may not suit:

• Businesses wanting the absolute lowest flat in-person rate — Flatpay’s 1.49% Terminal undercuts Square’s 1.75%
• Businesses that want on-site professional installation and configuration

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Verdict

Flatpay and Square serve different masters. Flatpay is for the merchant who wants one thing done really well: taking in-person card payments at a low, predictable rate, with a real person setting everything up. Square is for the merchant who wants one platform for everything: payments, online selling, bookings, staff management, and loyalty — all connected.

If you primarily trade in person with no need for online channels or digital tools — Flatpay’s 1.49% Terminal with on-site installation is a strong proposition. The absence of FCA authorisation disclosure is a legitimate due diligence concern; verify at register.fca.org.uk before committing.

If you sell online as well as in person, or if you plan to grow into multi-channel commerce — Square’s ecosystem is significantly more capable. The 1.75% in-person rate is slightly higher, but the breadth of tools, the £0 chargeback fee, and the strong hardware warranty more than compensate for most merchants.