Tether Promises Long-Awaited Audit—But Keeps Accounting Firm a Mystery

Tether says it has hired a Big Four accounting firm to conduct the first full independent audit of the reserves behind USDT.

The stablecoin issuer announced the engagement on March 24 but did not name the firm or say when the audit would be completed. USDT has a market capitalisation of about US$184 billion (AU$263 billion), while Tether says total reserves stand at roughly US$192 billion (AU$275 billion).

Chief executive Paolo Ardoino said the audit is meant to strengthen confidence in the stablecoin’s reserve infrastructure, and CFO Simon McWilliams said the firm was chosen through a competitive process and that onboarding, including reviews of systems, controls and reporting, had already been completed.

The Big Four Firm was selected through a competitive process because the organization is already operating at Big Four audit standard; the audit will be delivered.

Simon McWilliams, chief financial officer of Tether.

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Pressure to go Beyond Attestations

The announcement matters because Tether has promised a full audit before and failed to deliver one. A 2017 engagement with Friedman LLP ended without a completed report, and Ardoino said in 2025 that securing a Big Four firm had proved difficult.

Until now, Tether’s reserve disclosures have relied on quarterly attestations from BDO Italia. Those reports provide limited assurance at a specific point in time, rather than the deeper examination of internal controls and asset verification expected in a full audit.

The timing also reflects rising regulatory pressure. The GENIUS Act, signed in July 2025, requires foreign stablecoin issuers handling more than US$50 billion (AU$71 billion) in volume to undergo annual reserve audits. Tether is well above that threshold.

Tether says most of its reserves are held in US Treasury bills, with smaller positions in Bitcoin, loans and about 148 tonnes of physical gold valued at around US$23 billion (AU$32 billion).

Its reserve claims have faced scrutiny for years, and we’re talking way back. In 2021, Tether paid US$18.5 million (AU$25 million) to settle with the New York Attorney General over misleading statements about backing. 

The CFTC also fined the company US$41 million (AU$58 million) for overstating the extent of its dollar reserves.

The new audit could become Tether’s most significant transparency test yet, but for now the company has offered a promise without a firm name or deadline.

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