UK card-terminal fee structures explained
UK card-terminal pricing is genuinely confusing. The same merchant can be quoted "1.4%", "1.65% blended", "0.3% + 0.05 + interchange", "1.69% flat", or "tiered, qualified rate 1.95%". They are all different pricing models, and the headline number does not directly compare. This guide explains what each model means, when it works in your favour, and the hidden fees that catch operators out.
The four main UK pricing models
Flat rate: one number for every transaction (1.69% SumUp, 1.75% Square, 1.5% Tide). Simple, predictable, fair to small operators, expensive at high volume. Blended rate: one number that bundles interchange, scheme fees and the acquirer margin (1.4% to 1.9% Dojo, bespoke Tyl). Cheaper than flat at higher volumes. Interchange-plus (IC++): the underlying interchange + scheme fees passed through directly, plus the acquirer margin separately (Adyen, some Stripe deals, Worldpay enterprise). Most transparent at high volume. Tiered: a "qualified" headline rate applies to standard cards but premium and corporate cards downgrade to "mid-qualified" or "non-qualified" tiers at much higher rates. Worldpay and Barclaycard legacy contracts use this. Often the most expensive model for the merchant.
Why the same headline number means different things
A 1.5% blended rate from Dojo is genuinely 1.5% all-in (subject to volume bands). A 1.5% qualified-tier rate from a legacy Worldpay contract can be 1.5% for some transactions, 2.5% for premium-tier card transactions, and 3% for corporate-card transactions. The actual cost depends on your transaction mix. If you take a lot of business-to-business cards (corporate cards), tiered pricing is much more expensive than the headline suggests. Always ask: "is this rate the all-in cost, or is there a downgrade structure I should see?"
Interchange and scheme fees, the underlying cost
Every UK card transaction has an underlying cost the acquirer pays to the card scheme (Visa, Mastercard, Amex). Interchange is paid to the issuing bank; scheme fees are paid to Visa or Mastercard. Together they typically run 0.2% to 1.6% depending on card type. UK consumer debit is the cheapest (~0.2%). UK consumer credit is mid (~0.3% to 0.6%). Premium and corporate cards run 1.0% to 1.6%+. International cards (US-issued, EU-issued) run higher. Interchange-plus pricing exposes this; blended and flat-rate pricing absorb it into the headline. The acquirer's margin sits on top.
Monthly platform fees and the small-print costs
Headline transaction rate is rarely the whole picture. Watch for: monthly platform fee (£15 to £30 typical for contract products, £0 for SumUp/Square/Zettle), PCI compliance fee (£3 to £15 a month, often hidden), authorisation fee (£0.01 to £0.05 per transaction on top of the rate), statement fee (£0 to £5 a month), chargeback fee (£15 to £25 per chargeback, often non-refundable even on chargebacks you win), early-termination fee, and minimum monthly transaction fee (you pay it even if you do not trade). Total cost of acceptance is rate × volume + monthly fees + ad-hoc fees; not just the rate.
Worked example: £15k monthly volume
Dojo Go blended 1.5%: £15,000 × 1.5% × 12 = £2,700 / year. Plus typical £0 platform fee. Total: £2,700. SumUp Solo flat 1.69%: £15,000 × 1.69% × 12 = £3,042 / year. Plus £0 platform fee. Total: £3,042. Worldpay tiered 1.5% qualified, 2.5% premium, 3% corporate (assuming 70% qualified, 20% premium, 10% corporate mix): blended effective rate ~1.85%. £15,000 × 1.85% × 12 = £3,330. Plus £25/month platform = £3,630. The Worldpay tiered headline of 1.5% actually costs more than the SumUp flat 1.69%. Tiered pricing is the trap.
When each model wins
Flat rate (SumUp, Square, Zettle, Tide): wins for sub-£15k monthly volume. Predictable, no contract, no surprises. Blended (Dojo, Tyl): wins £15k to £100k monthly. Better all-in cost than flat at scale, simpler than IC++. Interchange-plus (Adyen, enterprise Stripe): wins £100k+ monthly, especially with a low-premium-card transaction mix. Maximum transparency. Tiered (Worldpay legacy): rarely wins for the merchant in 2026; if you have a tiered contract, run the comparison and consider switching.
FAQs
What is the difference between blended rate and interchange-plus?
Blended bundles interchange, scheme fees and acquirer margin into one number (e.g. 1.5%). Interchange-plus splits them: interchange + scheme fees pass through directly (typically 0.2% to 1.6% depending on card type), and the acquirer margin is quoted separately (typically 0.1% to 0.5%). Interchange-plus is more transparent and usually cheaper at high volume; blended is simpler at low to mid volume.
Why is tiered pricing risky?
Tiered pricing quotes a "qualified" headline rate but downgrades premium and corporate-card transactions to higher tiers (often 2.5% to 3.5%). The actual cost depends on your transaction mix, which you cannot fully control. UK acquirers are moving away from tiered in 2026 but legacy Worldpay and Barclaycard contracts still use it. Always ask for the full tier schedule before signing.
Are flat-rate products always more expensive at high volume?
Usually yes. SumUp's 1.69% flat rate at £30k monthly volume costs £6,084 a year. Dojo's blended 1.5% at the same volume costs £5,400. The £684 saving from blended pricing exceeds the cost of a 12-month contract risk. Above £30k monthly, flat-rate products become uncompetitive.
What hidden fees should I watch for?
Monthly platform fee, PCI compliance fee, authorisation fee, statement fee, chargeback fee, early-termination fee, and minimum monthly transaction fee. Together these can add £25 to £75 a month to a contract product. SumUp, Square, Zettle, Tide and Revolut publish these clearly (mostly £0). Worldpay and ISO-deployed PAX A920 contracts often hide them; ask for a written schedule of all fees before signing.
Related terminal reviews
Related rankings
Get a quote
Open quote form →Reviewed by Oliver Mackman, Director. Last reviewed: 2026-05-09.