Tether announced on Tuesday that it has engaged a Big Four accounting firm to conduct what the firm says is its “first full independent financial statement audit.” The issuer of USDT, the largest stablecoin by market cap with over $184 billion, did not name which specific firm would conduct the audit, and described it as potentially the largest inaugural audit in financial markets history.
The company, which reports a global user base of more than 550 million, said the engagement follows a competitive onboarding process during which multiple audit firms assessed Tether's systems, internal controls, and financial reporting.
The move comes after years of criticism over Tether's transparency practices. Rather than full audits, Tether has historically provided quarterly attestations from BDO Italia — a more limited form of financial review. In 2021, the Commodity Futures Trading Commission (CFTC) issued a $41 million fine over misleading claims that USDT was fully backed by U.S. dollars.
No timeline for completion of the audit was disclosed in today’s announcement.
As The Defiant reported in 2023, then-CTO Paolo Ardoino — now CEO — attributed the lack of a full audit in part to difficulties with auditing firms themselves.
More recently, both the EU's MiCA framework for digital asset regulation and the U.S. stablecoin-focused GENIUS Act have included provisions calling for full reserve backing and transparent audits of stablecoin issuers, as The Defiant reported previously. In November, S&P Global downgraded USDT's dollar-peg stability score to its lowest mark, citing growing exposure to higher-risk assets.
Tether credited the appointment of CFO Simon McWilliams in early 2025 as key to preparing the company's internal architecture for a full audit, per today’s announcement. McWilliams said the firm was "selected through a competitive process because the organisation is already operating at Big Four audit standard."
The announcement comes alongside Tether's broader push into the U.S. market. Last August, the company hired Bo Hines, former executive director of the White House Crypto Council, as a strategic advisor overseeing its U.S. expansion. More recently, Tether invested $200 million in commerce platform Whop, building on the launch of its regulated U.S. stablecoin USAT, which it first unveiled in September.
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