Tether Hires Big Four Firm for First Full Audit of $184 Billion USDT Reserves

Tether selected an unnamed Big Four accounting firm to conduct its first full financial statement audit, a step it has promised and failed to deliver for nearly a decade.

Tether announced Tuesday it has selected a Big Four accounting firm to conduct its first full financial statement audit, a step that would address the longest-running transparency question in the stablecoin industry. The company did not name the firm.

The distinction between what Tether has done and what an audit requires is significant. For years, Tether published quarterly attestation reports through BDO Italia that confirm reserve balances at a single point in time. A full financial statement audit goes further: it involves a continuous review of assets, liabilities, internal controls, and reporting systems. Tether’s reserves currently sit at $184 billion, making USDT by far the largest stablecoin in circulation.

The announcement arrives with considerable baggage. Tether has floated audit plans multiple times over its history. A 2017 engagement with Friedman LLP ended without a completed report. In 2021, the CFTC fined the company $41 million for misrepresenting its reserves. CFO Simon McWilliams, appointed in March 2025, was hired specifically to advance the audit process. “The Big Four Firm was selected through a competitive process because the organisation is already operating at Big Four audit standard,” McWilliams said Tuesday.

This story is an excerpt from the Unchained Daily newsletter.

What has changed is the regulatory environment. The GENIUS Act, signed into law in July 2025, requires stablecoin issuers with more than $50 billion in volume to undergo annual audits. Tether, at $184 billion, has no path around that requirement. The company now says more than 80% of its reserves are held in U.S. Treasury bills, a composition that should simplify the audit process considerably. Whether a Big Four firm actually delivers a clean opinion on the world’s largest stablecoin remains the open question. Tether’s track record demands patience before celebration.