Tether (USDT) announced Tuesday it has engaged a Big Four accounting firm to conduct its first full independent financial statement audit of USDT reserves, covering a $184 billion stablecoin that has operated without one since its 2014 founding.
The company did not disclose which firm was selected, and no completion timeline was given.
The audit goes beyond the quarterly attestations Tether has historically published through BDO Italia.
A full financial audit covers assets, liabilities, internal controls, and reporting systems on a continuous basis - the standard applied to publicly traded companies. The Big Four firms are Deloitte, EY, KPMG, and PwC.
Context: Years of Scrutiny
Tether has faced persistent questions about USDT's reserve backing since its founding. In November 2025, S&P Global downgraded USDT's peg stability score to its weakest level, citing higher-risk assets rising to 24% of reserves and persistent disclosure gaps.
Bitcoin represented approximately 5.6% of reserves - more than the implied coverage buffer at that time.
Tether's Q3 2025 attestation showed total reserves of roughly $181 billion, with approximately $135 billion in U.S. Treasuries.
CEO Paolo Ardoino publicly disputed the S&P assessment.
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What the Engagement Covers
The onboarding phase - which included a review of Tether's systems, internal controls, and financial reporting - concluded several weeks ago, the company said.
CFO Simon McWilliams, appointed in early 2025, said the firm was chosen because "the organisation is already operating at Big Four audit standard."
The audit will cover digital assets, traditional reserves, and tokenized liabilities. Tether said it will also be moving certain listed securities as part of the process.
Regulatory Backdrop
The move arrives under pressure from two directions. The GENIUS Act, signed in July 2025, requires foreign stablecoin issuers operating in the U.S. to undergo reserve audits.
The EU's MiCA framework imposes its own transparency requirements on stablecoin issuers active in European markets. Tether has previously said it intends to comply with both.
Tether has announced an engagement - not a completed audit. The outstanding questions are which firm was hired, when the audit will finish, and what it will actually reveal about reserve composition and counterparty arrangements.
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