📋 What Is an Attestation?
An attestation is a formal review conducted by an independent accounting firm that provides limited assurance on specific financial figures or statements. In the context of stablecoins like USDT, an attestation verifies that the issuer's reported reserve assets match the liabilities (tokens in circulation) and that the figures are accurate based on the procedures performed.
Attestations are governed by professional standards that dictate the scope and methodology of the review. The attestation report includes a letter from the accounting firm confirming that the reported figures are accurate and that the reserves are held in accordance with the stated policies.
Attestations provide a level of independent verification that helps build trust in stablecoins. They assure users that the issuer holds assets sufficient to redeem all tokens, reducing the risk of a de-pegging event and supporting confidence in the stablecoin.
⚖️ Attestation vs. Audit: Key Differences
Understanding the distinction between an attestation and a full audit is essential for interpreting the level of assurance provided.
| Feature | Attestation | Full Audit |
|---|---|---|
| Scope | Specific financial figures | Full financial statements & controls |
| Assurance Level | Limited | Reasonable / High |
| Internal Controls | Not examined | Tested in detail |
| Transaction Testing | Limited | Extensive |
| Time Required | Faster | Longer |
| Cost | Lower | Higher |
| Tether's Current Status | Yes | Planned |
The key takeaway: an attestation provides a snapshot of specific figures, while an audit offers a comprehensive examination of the entire financial picture. Tether currently provides attestations but has announced plans to transition to full audits.
Attestations allow Tether to provide timely transparency on a quarterly basis. Full audits are more time-consuming and may not align with the pace of stablecoin operations. However, Tether is moving toward full audits to meet growing demand for higher assurance.
⚙️ Tether's Attestation Process
Tether's attestation process is carried out by BDO, a top-five global independent accounting firm. The process typically involves the following steps:
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1
Data Collection
Tether compiles its Financial Figures and Reserves Report (FFRR), detailing total reserves, asset breakdown, and liabilities (USDT in circulation).
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2
Independent Review
BDO performs procedures to verify the accuracy of the reported figures. This includes confirming the existence and valuation of assets, reviewing custody arrangements, and checking for consistency.
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3
Attestation Report
BDO issues a formal attestation letter confirming that the figures are accurate based on the procedures performed. The letter is included in the published report.
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4
Publication
The attested report is published on Tether's website under the Transparency section, along with daily updates on the circulating supply.
BDO is a globally recognized accounting firm with a strong reputation. Their involvement adds credibility to Tether's attestations, as they are bound by professional standards and ethics.
📊 What Is Attested in Tether's Reports?
Tether's attestation covers the following key components:
- Total Reserves: The total value of all assets held in reserve, broken down by asset class.
- Liabilities: The total amount of USDT tokens in circulation (the liability owed to token holders).
- Excess Reserves: The difference between total reserves and liabilities, representing a buffer above the 1:1 backing.
- Asset Composition: A detailed breakdown of the types of assets held, including U.S. Treasuries, gold, Bitcoin, repurchase agreements, money market funds, secured loans, and bank deposits.
| Component | What It Shows | Why It Matters |
|---|---|---|
| Total Reserves | Total value of assets held | Confirms the stablecoin has backing |
| Liabilities | USDT in circulation | Represents the obligation to token holders |
| Excess Reserves | Assets above liabilities | Provides a safety buffer |
| Asset Breakdown | Composition of reserves | Indicates risk profile (Treasuries = low risk; Bitcoin = higher risk) |
Excess reserves are a key indicator of stability. A positive excess reserve means the stablecoin is over-collateralized. As of Q4 2025, Tether's excess reserves were approximately $6.34 billion, representing a collateralization ratio of about 103-104%.
⚠️ Limitations of Attestations
While attestations provide valuable transparency, they have inherent limitations:
Attestations focus on specific figures and do not examine internal controls or operational processes. They provide less assurance than a full audit.
Unlike an audit, attestations do not test the effectiveness of internal controls, which are critical for preventing errors and fraud.
Attestations reflect the figures at a specific point in time. They do not guarantee that the reserves remain at the same level between attestation dates.
Attestations are performed quarterly, leaving gaps in transparency between reports.
Tether addresses some of these limitations by providing daily updates on the circulating supply and by announcing plans to transition to full audits, which would offer greater assurance.
📜 History of Tether's Attestations
Tether's transparency journey has evolved significantly over the years:
- 2021: Tether began publishing quarterly attestations with the accounting firm Moore Cayman.
- 2022: The company transitioned to BDO, a more globally recognized firm, to enhance credibility.
- 2023: Tether started providing more granular asset breakdowns in its attestations, including the proportion of U.S. Treasuries and other specific asset classes.
- 2024: The company introduced the disclosure of excess reserves, providing greater transparency into the buffer above liabilities.
- 2025: Tether announced plans for a first full audit with a Big Four accounting firm, signaling a move toward the highest level of transparency.
This evolution reflects Tether's commitment to improving transparency and addressing market concerns, which has helped maintain USDT's position as the leading stablecoin.
🔍 How to Interpret an Attestation Report
When reading a Tether attestation report, focus on these key indicators:
- Excess Reserves: A positive number indicates the stablecoin is over-collateralized. Negative would be a red flag.
- Asset Quality: A high percentage of U.S. Treasuries and cash equivalents indicates a conservative, liquid portfolio. A growing share of Bitcoin or secured loans indicates higher risk.
- Trend Over Time: Compare the current report with previous quarters. Is the reserve composition becoming more or less conservative?
- BDO's Opinion: The attestation letter from BDO confirms that the figures are accurate based on the procedures performed.
If you see that U.S. Treasuries have increased from 55% to 64% over a year while secured loans have decreased, it suggests a shift toward safer assets — generally positive for stability.
🚀 The Future of Attestations and Full Audits
Tether has announced plans to transition from attestations to full audits with a Big Four accounting firm. This represents a significant step forward in transparency and would provide a higher level of assurance to users, regulators, and the broader market.
A full audit would involve a comprehensive examination of Tether's financial statements, internal controls, and operational processes. It would provide reasonable assurance that the reported figures are accurate and that the company is managing its reserves responsibly.
The transition is expected to further strengthen confidence in USDT and set a new standard for stablecoin transparency.
A full audit would provide even greater confidence that USDT is fully backed and that Tether is operating with the highest standards of transparency and accountability.
🏆 Best Practices for Using Attestation Information
- Verify Regularly: Check the latest attestation report before making significant decisions involving USDT.
- Compare Over Time: Track changes in reserve composition to identify trends.
- Assess Asset Quality: Favor stablecoins with a high proportion of liquid, low-risk assets.
- Understand the Limitations: Recognize that attestations are not full audits and plan accordingly.
- Cross-Check with Other Sources: Use independent analysis and market sentiment to complement the attestation.
- Stay Informed: Follow Tether's announcements regarding changes to its reporting practices.
Deepen your understanding with our guides on What Backs USDT, Reserve Reports, and USDT Transparency.