Mastercard Asia/Pacific (Australia) Pty Ltd v Australian Competition and Consumer Commission [2026] FCAFC 37

This was a Full Federal Court appeal in a live ACCC civil penalty proceeding against Mastercard entities. The main competition case had not yet been decided. It was listed for trial from 13 April 2026 with an eight-week estimate.

The ACCC's case was that Mastercard developed a credit leverage strategy in 2017 aimed at discouraging merchants from using the eftpos network for debit transactions. The alleged mechanism was a set of strategic merchant agreements, or SMAs, under which merchants could receive incentives, including lower prices for credit card acceptance services, if they routed dual-network debit card transactions through Mastercard.

Mastercard did not deny entering into SMAs. Its position was that the agreements were entered into for legitimate commercial reasons, not for the anti-competitive purpose alleged by the ACCC. That made purpose the central battleground. The appeal then arose because Mastercard served affidavits from senior personnel explaining what they understood the strategy to be, and what they said it was not.

Mastercard filed and served affidavits from senior personnel including Richard Koh and Bobby Molu. Their evidence was directed to Mastercard's internal purpose and understanding of the SMAs. In broad terms, they said they did not understand Mastercard's strategy to be one of preventing eftpos from competing for debit routing.

Mr Koh's affidavit described his role in reviewing and approving Australian deals from a finance perspective. He said he was concerned that a proposed SMA could be interpreted as Mastercard leveraging favourable interchange rates in return for commercial benefits, which he considered potentially inconsistent with Mastercard's usual neutral role in relation to interchange. He said that concern led him to draft a paper in September 2017 after consulting others within Mastercard Singapore.

The judgment reproduces part of that paper. It said the Australia team wished to tie commercial obligations from merchants to the offering of strategic merchant rates and referred to potential reputational risks in leveraging preferential interchange rates for marketing promotions or merchant benefits. Mr Koh nevertheless said that his concern was not about using lower credit interchange rates to prevent or discourage merchants from routing debit transactions through eftpos, and that nobody had suggested anything along those lines to him.

Mr Molu's affidavit also addressed purpose. He said he had been consulted by Mr Koh in September 2017, referred to receiving an email and attached paper raising concerns, and said that to his knowledge it was not a strategy of Mastercard Australia or Mastercard Singapore to use SMAs to hinder eftpos' ability to compete for debit transactions. He also said that was not his objective when approving or signing SMAs.

The problem for Mastercard was that these affidavits did more than deny the ACCC's allegation in a bare way. They gave a positive account of internal purpose, internal concerns and internal decision-making. The ACCC sought production of categories of documents that Mastercard said were confidential and privileged. The primary judge held that Mastercard had impliedly waived privilege over communications relevant to the matter it had put in issue.

The Full Court had to decide two connected questions. First, was implied waiver limited to cases where a party makes express or implied assertions about the content of confidential communications themselves? Mastercard argued for a narrower approach. The ACCC argued that waiver could also arise where a party opened a broader subject-matter to scrutiny.

Second, could implied waiver arise before the affidavits were read into evidence at trial? Mastercard argued that any waiver should not operate until that later point. The Court had to consider not only privilege principles, but also case management and the overarching purpose of civil practice under the Federal Court of Australia Act.

The Court referred to the established principle from Mann v Carnell that implied waiver turns on inconsistency. The question is whether the privilege holder has acted inconsistently with maintaining the confidentiality that privilege is intended to protect. That is an objective assessment. It does not depend on whether the party subjectively intended to waive privilege.

The Full Court dismissed the appeal. It held that the primary judge did not err in concluding there was an implied waiver of the content of confidential communications relevant to a matter put in issue by Mastercard. It also held that waiver at the pre-trial stage was not dependent on reading the affidavits into evidence.

The Court's catchwords state the point directly. Implied waiver is not limited to the making of express or implied assertions about the content of confidential communications. It can arise from opening a subject-matter to scrutiny. In this case, the subject-matter was Mastercard's purpose in devising and implementing the commercial transactions and SMAs.

That matters because Mastercard's affidavits were not merely procedural documents. They were part of Mastercard's substantive response to the ACCC's allegation about anti-competitive purpose. The affidavits said, in effect, that the relevant decision-makers did not hold the anti-competitive purpose alleged and that their concerns were of a different kind. Once Mastercard chose to advance that account, the Court held it was open to find that maintaining privilege over related confidential communications on the same subject was inconsistent.

The Court also rejected the idea that the issue had to wait until trial. The judgment says the Court considered case management and the overarching purpose of civil practice as relevant to the assessment of inconsistent conduct. In practical terms, that means courts can deal with waiver issues when affidavits are served and production is sought, rather than postponing the issue until the hearing itself.

This case is a warning about the interaction between witness evidence and privilege. Many businesses assume privilege is only at risk if they expressly rely on legal advice, quote a lawyer, or disclose the contents of a confidential communication. The Full Court confirmed the position is broader. If your evidence opens a subject-matter, especially purpose, motive, internal reasoning or internal concerns, the court may find it inconsistent to keep related privileged communications hidden.

The risk is highest where the business wants to prove that it acted for proper commercial reasons. That is common in competition cases, consumer law disputes, shareholder disputes, employment matters involving motive, and director duty cases. A witness may honestly want to explain what the company was trying to achieve and what was not intended. But once that evidence is served, the other side may argue that fairness requires access to related internal communications on the same topic.

Businesses should also note the timing point. The Court confirmed that waiver can be found before trial. So this is not something to leave until the hearing. It needs to be considered when affidavits are being drafted, when privilege reviews are being done, and when decisions are made about how much of the internal story to put forward through witness evidence.

No case can eliminate waiver risk entirely, but businesses can manage it better. Start by deciding what factual propositions really need to be proved through affidavit evidence. If the issue is commercial purpose, ask whether the witness needs to give a broad narrative of internal thinking, or whether the evidence can be confined to objective facts, process and personal involvement.

Next, review draft affidavits alongside the privilege log and the underlying document set. If a witness says there was no anti-competitive purpose, no intention to hinder a competitor, or that internal concerns were of a different kind, ask what emails, papers, legal reviews or internal discussions sit behind that proposition. If there are privileged communications on the same subject, there may be a waiver argument.

Also be careful with references to internal consultations. In this case, the affidavits referred to consultations with others and to an internal paper that reflected an internal consensus. That kind of evidence can make it easier for the other side to argue that the company has opened the field and cannot fairly withhold related communications.

Finally, remember that the court may deal with the issue before trial. That means the drafting stage is the right time to assess risk. Once an affidavit is served, the strategic options may narrow quickly.

The Full Court delivered judgment on 30 March 2026. The appeal was from orders made by the primary judge on 29 August 2025 in Australian Competition and Consumer Commission v Mastercard Asia/Pacific Pte Ltd (No 3) [2025] FCA 1043. At the time of the appeal judgment, the main ACCC proceeding was listed for trial commencing on 13 April 2026 with an eight-week estimate.

The Full Court ordered that the appeal be dismissed and that the appellants pay the ACCC's costs as taxed, assessed or otherwise agreed.