Blended PAYG rates are the simplest basis for comparison across providers, but they hide the three-layer cost structure of interchange, scheme fees, and acquirer margin. High-volume merchants on interchange-plus contracts will pay well below the PAYG range; the headline rate is a starting point, not a target.

BusinessExpert partner providers are listed first. Providers without a published PAYG rate operate on negotiated interchange-plus contracts or subscription models. All rates are indicative (Q1 2026) and carry Experimental status until backed by citation-engine observations.

At £20,000 monthly card volume and a £45 average ticket, the difference between the lowest and highest published PAYG rates runs to roughly £220/month. The gap narrows when merchants negotiate interchange-plus contracts at higher volumes, but the relative ordering tends to hold.

The table below shows an indicative monthly cost for each provider at the default assumptions. BusinessExpert partner providers are listed first. Providers without a published PAYG rate require a quote from the provider directly.

A headline rate buries three separate costs into one number: the interchange fee paid to the card-issuing bank, the scheme fee paid to Visa or Mastercard, and the acquirer's own margin. Tier-1 acquirers expose all three on an interchange-plus contract; resellers and SaaS platforms collapse them into a single blended rate.

For a typical UK debit transaction, interchange is capped at 0.2% by the EU Interchange Fee Regulation as retained in UK law, scheme fees run roughly 0.05–0.10%, and acquirer margin accounts for the rest. A 1.4% blended rate therefore implies an acquirer margin closer to 1.0–1.1%.

The wider the fee range, the more weight a merchant's negotiating leverage carries. Tier-1 acquirers publish narrow bands because their model is interchange-plus and the interchange portion is fixed by regulation. Resellers publish wide bands because the blended rate captures different merchant profiles, terminal types, and contract lengths.

A merchant on a 1.8% reseller rate is paying roughly 1.5–1.6% acquirer margin once interchange and scheme fees are stripped out. A merchant on a 0.40% interchange-plus rate is paying acquirer margin in the 0.10–0.20% range. The difference is typically more about scale and contract terms than about any structural difference between providers.

Two cost layers sit outside the EU Interchange Fee Regulation caps that bound domestic UK consumer-card transactions: cross-border transactions on consumer cards (post-Brexit), and commercial cards of any nationality. Both are material for SMEs that take a meaningful share of their card volume from EEA shoppers or from corporate buyers.

UK→EEA consumer card interchange: 1.5% (Payment Systems Regulator — Market Review MR22/2.7 — Cross-Border Interchange, 23 April 2022)

Commercial card interchange: 1.65%–1.90% (Visa — Visa Domestic UK Interchange Reimbursement Fee Schedule, 15 April 2025)

Scheme fees are the second of the three layers in a card-acquiring rate (after issuer interchange and before acquirer margin). They are set by Visa and Mastercard, not by regulators, and have risen materially in real terms since 2017 — a finding the Payment Systems Regulator confirmed in its market review of card-scheme and processing fees (MR22/1.10).

Annual £-value uplift to UK businesses: £170 million (Payment Systems Regulator — Market Review MR22/1.10 — Scheme and Processing Fees, 2017-01-01 – 2023-12-31)

Ancillary fee categories: Ancillary and optional fees beyond interchange and core scheme fees (PSR MR22/1.10 Final Report, 6 March 2025 + Mastercard 2026 updates): Categories identified by PSR (MR22/1.10 Annex 4 — specific magnitudes commercially redacted): - Behavioural fees: levied on acquirers based on merchant activity (chargebacks, late settlements, failed transactions). Described as 'optional in theory but practically mandatory to avoid business disruption.' - Digital Enablement fees: charged for token-based or digital wallet transactions. Mastercard Digital Enablement Service fee (effective April 2026): USD 0.025 per transaction ≤$100; variable 0.00025 × auth value for $100–$2,000; capped at USD 0.50 per transaction ≥$2,000. - Optional services with limited competitive alternatives: dynamic currency conversion, reporting services, CVC verification, credential continuity programs. - Network authorisation / force-post fees: Mastercard Force Post Transaction fee published for US region (USD 0.09/transaction, April 2026); UK applicability TBD. PSR key finding: 'There are no formal definitions in the industry of which fees are behavioural, optional, or mandatory.' Fee magnitudes in Annex 4 are redacted in the publicly published version of the report. (Payment Systems Regulator — Market Review MR22/1.10 — Scheme and Processing Fees, 6 March 2025)

PSR ITC remedy: PSR transparency remedies for card scheme and processing fees (as at April 2026): 1. Specific Direction 14 — Merchant Summary Box (LIVE, varied 29 May 2024): Acquirers must provide a free, standardised summary box to merchants with annual card turnover ≤£50 million. The box itemises: interchange fees, scheme fees, and acquirer service fees as separate line items. PSR provides a template; charge to merchant for this summary is prohibited. Effective since July 2023; SD14/15/16a variation published 29 May 2024 updated implementation guidance. 2. ITC Remedy — Scheme Transparency to Acquirers (CONSULTATION, not yet live): PSR CP25/3 (December 2025) proposes to require Visa and Mastercard to provide acquirers with clear, timely data on scheme and processing fees — 6 months' notice for new/modified fees, 3 months for behavioural fee changes, and transaction-level reconciliation data. Consultation closed 13 February 2026. Final direction expected 31 March 2026. Effective date for ITC obligations not yet published. (Payment Systems Regulator — Specific Directions 14, 15, 16 — APP Reimbursement, 29 May 2024)