Tether hires Big Four auditor for first full reserves audit

Tether says it is moving toward its first full financial audit and has hired a Big Four accounting firm to examine the reserves behind its USDT stablecoin, the largest among fiat-pegged tokens.

The company said it has formally engaged a top-tier auditor to complete a comprehensive review of its financial statements, marking a shift away from the quarterly attestations that have defined its transparency efforts to date.

"The Big Four Firm was selected through a competitive process because the organisation is already operating at Big Four audit standard," said Simon McWilliams, Tether's CFO. "The audit will be delivered," he added.

Tether did not disclose which firm it selected. The so-called Big Four includes Deloitte, PwC, EY, and KPMG. Deloitte has previously issued a reserve attestation for Tether-linked USAT — a U.S.-regulated stablecoin issued via Anchorage Digital — though that review was limited to a point-in-time snapshot and did not extend to USDT or Tether’s broader finances.

End to a long era of FUD?

For years, the company has faced scrutiny over whether its tokens are fully backed, publishing attestations that confirm reserve balances at a point in time but fall short of a full audit of its accounts. A completed audit would provide a more detailed and continuous view of assets, liabilities, and internal controls.

Tether said the engagement followed a competitive process and comes after years of internal work to strengthen governance, reporting systems, and reserve management. The company added that the audit will cover a complex balance sheet spanning digital assets, traditional reserves, and tokenized liabilities.

"Trust is built when institutions are willing to open themselves fully to scrutiny," said Tether CEO Paolo Ardoino.

USDT remains the largest stablecoin in circulation, with a market capitalization above $180 billion and more than 500 million users globally, according to the company.

The scale has made Tether a significant player in short-term government debt markets, with executives previously signaling it could rank among the largest buyers of U.S. Treasury bills.

Hiring a Big Four firm arrives as Tether has been expanding its geographical footprint and corporate size.
The company recently launched a U.S.-focused stablecoin offering, USAT, and has outlined plans to add roughly 150 staff over the next 18 months as it scales operations. Earlier disclosures also showed continued user growth for USDT even during periods of market stress.

The Block reached out to Tether and the Big Four accounting firms for comment.