KP Law is leading a UK group action on behalf of qualifying businesses seeking damages from Mastercard and Visa for unlawful Multilateral Interchange Fees (MIFs) applied to credit, debit and prepaid card transactions.
Recent judgments of the Competition Appeal Tribunal (CAT) have confirmed that Visa and Mastercard set interchange fees in breach of UK and EU competition law. These practices resulted in UK merchants paying materially inflated fees over a prolonged period.
KP Law’s claim forms part of the ongoing Umbrella Proceedings in the CAT and focuses on the recovery of historic overcharges, including claims relating to corporate card transactions that have not been fully addressed by earlier settlements or judgments.
Each time a business accepted a Visa or Mastercard payment, a portion of the merchant service charge was allocated to the issuing bank in the form of a Multilateral Interchange Fee. These fees were set centrally by Visa and Mastercard and passed through the acquiring banks to merchants.
On 27 June 2025, the CAT delivered a landmark liability judgment confirming that Visa and Mastercard’s MIFs:
The Tribunal held that the MIF arrangements were unlawful “by object”, meaning they were inherently anti-competitive. As a result, merchants are not required to prove market impact and can instead focus on the quantification of loss.
Your business may be eligible to join the KP Law group action if:
Businesses may still be eligible even if they have ceased trading or previously entered into a settlement, subject to review.
Once you have initiated your claim with us, we will collect and analyse Visa/Mastercard sales data from the last six years, calculating the MIF’s applied to these transactions.
This will allow us to calculate loss by comparing your records to hypothetical scenario in which the MIF was not applied at all. This is a widely accepted methodology by the CAT for claims of this type.
KP Law has appointed Punter Southall Analytics Limited to undertake a forensic assessment of loss.
The claim is fully funded and pursued under a Damages Based Agreement (DBA). Legal fees are payable only in the event of a successful recovery. KP Law will arrange After the Event (ATE) insurance to protect against adverse costs exposure.
Subject to compliance with the DBA, participants bear no financial risk if the claim does not succeed.
Duncan Hedar is the solicitor leading KP Law’s Mastercard and Visa interchange fee proceedings. He specialises in high-value competition and collective redress litigation and has extensive experience managing complex, data-intensive claims in the Competition Appeal Tribunal. Duncan is responsible for overall legal strategy, coordination of expert evidence and engagement with the Tribunal and defendants.
Emma Birch is a Partner at KP Law overseeing the day-to-day conduct of the litigation. Emma focuses on claim management, procedural matters and client coordination, ensuring that participating businesses receive clear, timely advice and that the claim progresses in line with the CAT’s timetable and procedural requirements.
KP Law is a specialist collective redress law firm who has considerable experience in successfully resolving group claims on behalf of thousands of claimants. Our team have extensive experience bring claims to the CAT and in interchange fee litigation.
Joining a group claim allows your business to benefit from the power of collective bargaining, while eliminating your upfront costs. Our team will work hard on your behalf to ensure you receive the best outcome possible for your business.
FAQs about the Mastercard & Visa Group Action
Civil litigation between commercial counterparties is common. KP Law can review relevant agreements where appropriate, but any decision to proceed remains a commercial judgment for your business.
Your time commitment is intentionally limited, we will make this process as simple and time effective as possible for you. Once you have provided us with all the necessary data, we will handle everything else.
Not necessarily. This claim relates to a new category of loss. Prior settlements may not cover these claims and may apply differently across corporate groups.
Claims of this scale and complexity require specialist external counsel. KP Law manages the entire process on a risk-free basis, allowing internal teams to remain focused on core business priorities.
There has been a long history of regulatory intervention, findings and litigation against Visa and Mastercard in relation to their MIFs, now going back some 20 years or more, in the UK, EU and US. This has resulted in many significant fines, settlements and awards against Visa and Mastercard.
Many of the previous settlements have however related to consumer cards. Our claim is in respect of both Commercial and Consumer Cards.
The only other Commercial Cards claims currently being pursued for merchants with an annual turnover of greater than £100m was issued in 2021 (“CICC Claim”). However, the time period for joining that claim closed in February 2025.
You may also have heard of a related ‘opt-out’ Commercial Cards claim being brought. Only smaller businesses (with an annual turnover less than £100m) are eligible for that claim.
Early participation maximises leverage, reduces procedural risk and avoids potential limitation issues or restrictions on future standalone claims.
Standing up for justice, our solicitors are pursuing claims against the affected claimants just like you.
You will only pay fees if your case is successful.*
Our team has extensive experience in claims and is committed to achieving the best outcome for you.
We are ready to take on large, deep-pocket companies that other law firms shy away from.
Together, let’s hold Mastercard & Visa accountable and secure the compensation you deserve.
*Subject to the terms and conditions of your retainer with us