Interchange plus pricing UK providers sell has one property that a blended card rate lacks. When the fee kept by the customer's bank goes down, the shop's bill goes down with it, because the provider passes that fee through at cost instead of folding it into one fixed percentage.
The Payment Systems Regulator measured this after the 2015 caps. Its final report on card acquiring, published in November 2021, compared what happened to merchants on different prices and put the clearest result in one line: “Merchants on IC++ pricing received full pass-through of the IFR savings”.
Small and medium-sized merchants mostly sat on standard pricing. On average they got little or no pass-through of the same savings, and new customers paid less than existing ones.
We read the report again in October 2026. Beside it we read the UK text of the interchange regulation, the regulator's guidance for merchants and the current Visa and Mastercard tables for UK cards, because those documents decide what a shop can ask for.
The law is stricter on this point than one blended percentage suggests. Unless a merchant asked in writing for a blended charge, the acquirer must price each card category and brand separately.
Only interchange plus ties those prices to interchange itself. Only the double plus version shows the scheme fee as well, and that second line is the one a blended rate never shows.
A shop owner should know the pricing type before reading any rate. Ask each provider in writing which type the quote uses, make sure the answer names the scheme fees, and do not compare two headline percentages until both answers are in.
Interchange plus pricing UK: what does each line on a statement mean?
Each line stands for one part of the merchant service charge. That charge is the total a provider takes for accepting a card, and the regulator's report splits it into interchange fees, scheme fees and acquirer net revenue.
Interchange goes to the bank that issued the card. Mastercard's own page describes it from the scheme's side: “Interchange is a small fee typically paid by acquirers (retailer’s bank) to issuers (cardholder's bank)”.
For UK consumer cards it has a legal ceiling. The regulator's guide for merchants gives the caps as 0.2 per cent of the value of a transaction for consumer debit and prepaid cards and 0.3 per cent for consumer credit cards.
Scheme fees go to Visa or Mastercard instead. The regulator's glossary describes them as fees paid to the operator of a card payment system, covering both scheme services and processing services.
Acquirer net revenue is whatever the provider keeps. In the glossary it covers the provider's own costs of supplying the service, other than interchange and scheme fees, plus its margin.
On a blended statement all three arrive as one percentage. The shop then cannot see where interchange ends and the provider's margin begins.
Statements on interchange plus show the first part at cost. The glossary defines interchange fee plus pricing as a price “whereby for any given transaction, the acquirer automatically passes through at cost the interchange fee applicable to that transaction”.
The provider then adds a processing fee on top. The report says this fee is also called a management fee, and that acquirers selling interchange plus contracts compete on it rather than on a headline rate.
A hundred pounds of UK consumer debit sales carries twenty pence of interchange at most, by our arithmetic on the 0.2 per cent ceiling.
Visa's guide to fees adds a point about who sets the total. It describes the merchant service charge as a bundle of component fees and then states: “This rate is negotiated directly between the retailer and its bank”.
Bargaining therefore happens over the provider's own fee. On a double plus contract that fee is the single number worth comparing between two quotes, since interchange and scheme fees pass through at cost either way.
Blended vs interchange plus: which price falls when interchange falls?
Prices on interchange plus fall by themselves when interchange falls. A blended or standard rate falls only when the provider decides to lower it, and that difference runs through the whole pass-through chapter of the regulator's report.
The regulator calls this other type standard pricing. It covers any price that does not pass interchange through at cost.
Unlike interchange plus, the report says, “with standard pricing there will always be circumstances in which the same headline rate applies to transactions that attract different interchange fees”.
That paragraph also explains how such a rate gets built. The provider sets the headline rate high enough to recover interchange across the whole mix of cards the merchant accepts, plus its other costs, so one number can stay put while the fee underneath it moves.
Standard pricing is the normal case for small firms. The report puts its share at approximately 98 per cent of all small and medium-sized merchants, offered by most acquirers, independent sales organisations and payment facilitators.
Double plus merchants were very few in number. Yet they accounted for 77 per cent of transaction value, and the regulator put their benefit from the caps at around six hundred million pounds in 2018.
Its guide for merchants explains why a cap on interchange need not lower a shop's bill. “While the IFR caps certain interchange fees, it does not cap the MSC”, the guide says, and the merchant service charge is the figure a shop actually pays.
New customers paid less on average than existing ones. We read that as a sign that an old blended rate is rarely repriced unless the merchant asks for it.
Any shop on a blended rate should ask at renewal what changed. Ask whether the rate has moved since it was set and against which interchange figures, and do not accept a reply that names only the headline percentage.
Why does a single plus still hide the scheme fee?
A single plus contract passes through interchange alone. The scheme fees stay inside the provider's own charge, and the report draws that line in one sentence: “With IC+ pricing, only interchange fees are automatically passed on at cost”.
The processing fee then carries several costs at once. On such a contract it recovers some or all of the scheme fees, the acquirer's other costs and a margin, so the shop sees interchange clearly and everything else as one lump.
The double plus version opens that last box. In the report's words, “IC++ pricing automatically passes on interchange fees and scheme fees at cost to the merchant”, so the processing fee covers only the provider's other costs and margin.
Fees charged by the schemes moved fast in the years studied. The regulator's review of 2014 to 2018 found that they increased significantly, and that “a substantial proportion of these increases are not explained by changes in the volume, value or mix of transactions”.
Blended rates pass such rises on without a label. A rise reaches the shop only as a repriced headline figure, and nothing on the statement shows which of the three parts grew.
Single plus contracts behave the same way here. There the scheme fee sits inside the provider's charge, so a scheme rise and a margin rise look identical on paper.
Reading the statement settles which version is in place. By the regulator's definitions, a separate scheme fee line points to double plus, and an interchange line with one provider charge beside it points to single plus.
Does UK law allow one blended rate for every card?
UK law allows it, but only on written request. Article 9 of the UK version of the Interchange Fee Regulation carries the heading Unblending, and it sets the default the other way round.
Each acquirer must price card categories and brands separately. The article tells it to charge separately for categories and brands of cards with different interchange levels, “unless payees request the acquirer, in writing, to charge blended merchant service charges”.
The second paragraph reaches into the contract itself. Agreements must contain “individually specified information on the amount of the merchant service charges, interchange fees and scheme fees applicable with respect to each category and brand of payment cards”.
A merchant can later ask in writing for something different. Without such a request, the scheme fees belong in the agreement card category by card category, whatever pricing type the provider sells.
Article 12 deals with each individual card payment. After every sale the provider must give the payment's reference, its amount and the charges, “indicating separately the merchant service charge and the amount of the interchange fee”.
Grouping that information is allowed only with consent. With the merchant's prior and explicit consent it can be aggregated by brand, card category and interchange rate, and a contract may provide for it at least once a month, in a form the merchant can store unchanged.
Unblending in law differs from interchange plus pricing. A provider can comply with Article 9 by charging a fixed rate for each category of card, with no pass-through of interchange at all.
Stripe's UK price list is a published example. It charges 1.5 per cent plus 20p on standard UK cards and 2.8 per cent plus 20p on premium UK cards, the commercial, corporate and business cards in its own support page's definition.
The legislation.gov.uk page for Article 9 carries a status note. It lists a revocation by the Financial Services and Markets Act 2023 among the changes yet to be applied, so the unblending rule stands in the revised text as we read it this month.
Breaches can be reported to the regulator directly. Its merchant guide says the regulator may open an investigation after a complaint, and the Treasury made it the lead competent authority for the regulation in the UK.
How far apart are UK interchange rates on the cards a shop takes?
The range runs from 0.2 to about 2 per cent. The low end is a UK consumer debit card, the high end some business and corporate cards, and the consumer caps apply only when the shop, the acquirer and the issuer are all in the UK.
Mastercard's page states the boundary in the scheme's own terms. It says the UK version of the regulation caps interchange only on UK domestic consumer debit and credit transactions.
Business and corporate cards sit outside those caps. Visa's current UK table lists 0.75 per cent for a Visa Business Debit card used in person and 1.75 per cent for a Visa Corporate card.
Mastercard's commercial card table is the newer of the two. It lists 1.30 per cent for a Mastercard Business card tapped contactless and 1.75 per cent on a Mastercard World Elite Business card used the same way.
The schemes give slightly different answers on business debit. For a business debit card tapped at the till, Visa lists 0.75 per cent and Mastercard 0.70 per cent, so even two similar cards can cost a shop different amounts.
Our arithmetic shows the gap on a hundred pounds. That sum carries seventy five pence of interchange on the Visa business debit card, against twenty pence at most on a UK consumer debit card.
A blended rate must price that spread in advance. It rests on the provider's estimate of the card mix, so customers moving towards business cards cost the provider more, a counter full of consumer debit taps costs it less, and the rate stays where it was.
Pass-through pricing charges the mix the shop actually took. Business cards show up as business cards, consumer debit taps appear at their capped level, and the monthly total follows the customers rather than a guess made when the contract was signed.
Can a small shop or cafe get interchange plus pricing?
A small shop can ask, but offers go mostly to large merchants. The review is blunt on this point: “Most acquirers told us that IC+ and IC++ pricing is only available to, or suitable for, large merchants”.
One acquirer called both versions more complex and volatile. Its explanation in the report was that the cost of each transaction varies with the characteristics that drive interchange and scheme fees, so the merchant's cost per payment is not one fixed figure.
About 35 per cent of large merchants had either version. The report says they were typically the largest merchants of all, with annual card turnover above £50 million, and that most of the remaining large merchants stayed on standard pricing.
Published UK price lists follow the same pattern too. Stripe's UK pricing page lists IC+ pricing inside a custom package for businesses with large payments volume or unique business models, beside the standard rates anyone can see.
Asking still tends to work for those who try. In the regulator's merchant survey, 78 per cent of small and medium-sized merchants had never tried to negotiate with their provider, and nearly nine in ten of those who did got better price or non-price terms.
Growing shops are the group the report singles out. It says merchants with growing card turnover may benefit from comparing offers to see whether their current deal still fits their needs, and may otherwise end up paying too much.
The regulator's remedies make that comparison easier to run. Since July 2023 the fourteen firms named in its directions have had to send each business a summary box of key prices and show it prominently in the online account.
Trigger messages, sent near the end of a fixed-term contract, started on the same date.
Each fee entry in the box is a total. The format guidance asks providers to add interchange, scheme and acquirer fees into one figure per entry, so an interchange plus quote and a blended quote can sit side by side in the same layout.
What do the regulator's figures not tell a shop owner?
The report's figures describe the years around the caps. They do not describe any shop's contract this month: the benefit estimate is for 2018, and the scheme fee review starts in 2014.
Very small merchants are missing from one key finding. The regulator made no pass-through finding for merchants with annual card turnover up to £15,000, so the smallest card takers have no measured result either way.
Averages cannot price a single shop's card mix. The report gives results for groups of merchants, so it cannot say whether one cafe's blended rate is fair for its own customers.
Even a double plus contract leaves the provider's margin open. The processing fee is negotiated, and additional fees for events such as authorisation requests and chargebacks can sit beside it on the statement.
Scheme fee lines were the one part we could not test. The Visa and Mastercard tables we read list interchange only, so we could not check a scheme fee line against any published figure.
One shop's answer sits in its own contract and statements. A bookkeeper or accountant can rebuild last year's card costs under each quote, and the provider is the one to confirm in writing which pricing type the contract uses.
Is interchange plus worth asking for at the next renewal?
Our view is that interchange plus pricing UK shops can negotiate is worth asking for when many customers pay by business card. The same goes for any shop that has grown well past the turnover it signed at, because its blended rate was priced on a card mix and a size that may no longer exist.
Cafes taking mostly consumer debit have less to gain. A simple published rate can still be the easier contract there, provided the owner knows what sits inside it and checks it at each renewal.
Its final decision on remedies promises continued monitoring. The regulator says it will monitor the firms' compliance with its directions and the impact of the remedies, to decide whether any further action is required.
Article 9 is the next thing we are watching. If the revocation listed under the 2023 Act is applied, the question for every shop becomes what, if anything, replaces the unblending rule and the written request it requires.
The task before the next statement needs last month's statement and a pen. Find the interchange line and the scheme fee line; if neither exists, write to the provider asking which of the four pricing types applies and when blended charges were requested in writing.
Nobody in our sources publishes a newer count of small UK shops on interchange plus than the regulator's own. That count is now nearly five years old.